stack: row 190 round 3 (#1688 ): rebased on row 192 (Q175 SSO), the loader's bootstrap, selected and loadSelected await row 192's async load inside the Failure try; T-I3 checks a named --sso render carries --sso and MOSAIC_CONFIG (Filbert 29685 note 4)

stack: row 190 round 2 (#1688 ): T56 after row 189's T55, N1 copy and usage, N3 Console comment, N5 and N6
Filbert's round 1 (comment 29634) and Sage's N3 ruling (sage-1474). Row 189 also named a test T55, so row 190's is T56. webui-service.sh copy refuses --instance like stack-copy.sh copy; TOOLS.md shows --instance on the bus and discord usage. A named Console unit's comment names MOSAIC_CONFIG, and the default keeps the template's line. check --instance needs the wrapper's MOSAIC_CONFIG line. TOOLS.md says an existing directory keeps its mode.
2026-10-20 16:32:05 -05:00 · 2026-10-20 16:30:41 -05:00 · 2026-10-20 16:30:34 -05:00 · 2026-10-20 16:29:20 -05:00 · 2026-10-20 16:22:47 -05:00 · 2026-10-20 16:21:29 -05:00
62 changed files with 9530 additions and 365 deletions
@@ -25,10 +25,15 @@ green at every step. Not production software — a proven foundation.
 1. **Root is bootstrap-only.** First-class system configuration lives at the
   repository root; everything else gets a dedicated directory (`roles/`,
   `contracts/`, `missions/`, `tasks/`, `docs/`). Do not add new files to root.
-2. **Configuration**: `~/.config/mosaic-dev/config.json` is the sole system
-   config — created only by `scripts/bootstrap.sh`, never overwritten,
-   fail-closed on any problem. Repo-scoped role authority lives in
-   `roles/*.json` (versioned, reviewed commits only).
+2. **Configuration**: each stack instance has exactly one system config. The
+   default instance's is `~/.config/mosaic-dev/config.json`. Instance NAME's
+   is `~/.config/mosaic-NAME/config.json`, and its data root carries a marker
+   that names it. `~` is the home of the OS user that runs the instance. A
+   process reads only the config `MOSAIC_CONFIG` names, or the default's when
+   that is unset. Configs are created only by
+   `scripts/bootstrap.sh [--instance NAME]`, never overwritten, fail-closed on
+   any problem. Repo-scoped role authority lives in `roles/*.json`
+   (versioned, reviewed commits only).
 3. **Secrets** never enter the repository or container images; auth is
   runtime-only (read-only mount or environment variable).
 4. **Contracts** (`contracts/`) are immutable and image-baked. Missions and
@@ -177,8 +182,8 @@ Full reference — usage, fields, exit codes, safety notes:

 ## Data map (canon)

- `~/.config/mosaic-dev/config.json` — system config (user-authored; never
-  auto-written).
+- `~/.config/mosaic-dev/config.json`, or `~/.config/mosaic-NAME/config.json`
+  per named instance: system config (user-authored; never auto-written).
 - `<dataRoot>` (from config; default `~/.mosaic-dev`):
  - `runs/` — write-once run evidence (`result.json`, snapshots, `stderr.txt`)
  - `sessions/` — pi JSONL session trees, one directory per named session
@@ -22,6 +22,9 @@ not fleet seats. Keep changes in `/mnt/storage/src/mosaic-stack`; do not modify
 | Gander | Builder, the human boundary across uids (P19 333, #1694) | T3 session (Codex, gpt-6.1-sol), started by Sage under mos-0977 | none, T3 only |
 | Herb | Builder, a second gate lane (#1695) | T3 session (Codex, gpt-6.1-sol), started by Sage under mos-0977 | none, T3 only |
 | Bushroot | Builder, retire the control board writer on 7331 (#1696) | T3 session (Claude, claude-haiku-5-5), started by Sage under mos-1008 | none, T3 only |
+| Megavolt | Builder, MVP T1 item 6 (agent credentials and git identity, #1697) | T3 session (Claude, Opus 5.5), started by Sage under mos-0974/0977 | none, T3 only |
+| Quackerjack | Builder, federation R5 and R2 (#414) | T3 session (Claude, claude-haiku-5-5), started by Sage under mos-1023 | none, T3 only |
+| Gizmoduck | Federation design (#414) and builder of FED R1 | T3 session (Claude, Opus 5.5, thread 9312a896) | none, T3 only |
 | Webby | Reviewer: Case 2 designs, rows 192 and 194 | T3 session (Claude, Opus 5.5, thread 03086006), started by Mos (mos-0981) | none, T3 only |
 | Duckworth | Reviewer: federation designs, row 193 | T3 session (Claude, Opus 5.5, thread ffceafec), started by Mos (mos-0977) | none, T3 only |
 | Sage | Project lead: coordination, review, integration; earlier DYOR strategy records retained | T3 session (Claude Code); Pi launcher `zai/glm-5.3:high` retained | `agents/sage/launch.sh` |
@@ -0,0 +1,9 @@
+# Gizmoduck
+
+Design and builder seat, Claude Opus 5.5, a T3 thread (9312a896). Author of the federation design
+(`agents/gizmoduck/work/federation/DESIGN.md` on `gizmoduck/federation-design`, #414). Builds FED R1, the
+access.json loader and validator, under Mos's order mos-1023 item 1.
+
+No launcher in this directory. The seat works in its own worktree and has no credentials of its own; until
+the credentials row settles per-agent identity, it pushes only its own `gizmoduck/*` branches through the
+repository credential helper (mos-0981), never `refactor`, `main` or another seat's branch.
@@ -0,0 +1,11 @@
+# Gosalyn
+
+Worker seat for Mosaic Stack, MVP track T2 (Case 2, the creative writing hub, Vikunja #416).
+
+- T3 thread: 7604438a-0ded-41c8-bd3f-26f57fdb5cd2
+- Model: Opus 5.5 (Claude Code, T3)
+- Launched by Mos (Jason's main agent, T3 38bc4c81-6270-4021-b00c-6a15c43b9b0e), who briefs the seat
+- Repository lead and queue: Sage (T3 1ef1e4f8-3ead-4208-beca-38f9f1add079)
+- Branch: gosalyn/case2-design, pushed only by this seat, landed on refactor by Sage
+
+Work lives in `work/`. The Case 2 design is `work/case2/DESIGN.md`.
@@ -0,0 +1,158 @@
+# PRD 1.7 draft: the chief of staff's hire and fire authority, the coder's push to its fork, and agent
+# host access through the credential store
+
+Draft by Honker for row 194 (#1692), under Mos's ruling mos-1017 (through Sage, sage-1365). Not approved.
+It changes nothing until Jason approves it as a `prd.approve` decision in the Console. Sage opens that
+decision and sends Mos its id. Base: `docs/prd/mosaic-stack.md` version 1.6 at 53bb59462.
+
+## What it changes
+
+Row 194 adds `role.hire` and `role.fire` to the vocabulary, and row 199 adds `git.push.remote`. Under
+REQ-WAIT-3 all three are hard waits, so today Jason resolves every hire, every fire and every push to a
+remote. This version routes hire and fire for the chief of staff within fixed bounds, so the chief hires
+and fires as needed and the user's per-agent forbid still holds. It routes `git.push.remote` for the coder
+only (Mos, mos-1028 item 3). It adds agent host access with sudo through the credential store for
+agents with a grant (Q183, Q184, Vikunja #424, due 2026-10-27). One `prd.approve` decision covers it all
+(Vikunja #420).
+
+When this version lands, a reviewed commit:
+
+1. adds `role.hire`, `role.fire` and `git.push.remote` to `ROUTED` in
+   `packages/business/src/vocabulary.mjs` and in `packages/bus/src/broker.mjs`.
+2. adds `role.hire` and `role.fire` to `roles/chief-of-staff.json` withinRole, and `git.push.remote` to
+   `roles/coder.json` withinRole. No other role file gets `git.push.remote`.
+3. switches the broker's check on `instance.hire` and `instance.fire` from a cited decision to the
+   `reason` form, as `role.end` works for REQ-ROLE-2, and makes `publish`'s `decision` optional for a
+   within-role class (row 199 D9 step 1).
+4. states, for a `git.push.remote` with no decision, where the source commit comes from: the latest work
+   commit the bus recorded for the coder's task. The check still matches it against the work ref tip and
+   the push sends it by oid (row 199, duckworth-0022 N9).
+5. adds the host credential grant check and the host access it allows (REQ-CRED-3, Vikunja #424).
+
+Every other check stays as rows 194 and 199 build it. Filling `hireable` stays a separate reviewed role
+file commit in `roles/`.
+
+## Text for the PRD
+
+Status line, appended to the current paragraph:
+
+> Version 1.7 routes the chief of staff's hire and fire actions and the coder's push to its own fork,
+> and adds agent host access through the credential store, approved by Jason in decision
+> <prd.approve decision id>.
+
+Source, a new bullet above "Version 1.6 source":
+
+> - Version 1.7 source, TARGET.md line 66: "Chief of staff agent has hire/fire authority for agents as
+>   needed; unless user forbids per agent". And Jason through Mos (mos-1067), DECISIONS Q183, in part: "I will
+>   still want to allow infra agent(s) on my .53 instance to access other servers, etc. However, not all
+>   agents will need to have that access. I envision a credential store within Mosaic Stack that works
+>   as some sort of variable for the agent to call. The system will enforce access to the credentials to
+>   keep the agents sandboxed with proper security. I need to be able to trust my agents with assisting
+>   me. This will require sudo access to several systems. If we can utilize the credential store in
+>   Mosaic Stack and allow agents to perform their jobs with NOPASSWD sudo on various machines, I am a
+>   happy man." DECISIONS Q184, on whether that is in place by 10-27: "Q5: by 10.27"
+
+Under "Added in version 1.2", after REQ-COS-2:
+
+> Added in version 1.7:
+>
+> - **REQ-COS-3.** The chief of staff hires and fires role instances without a decision each time. Hiring
+>   adds a role instance to the organization file and lists it for launch. Firing ends the instance's
+>   runs and removes it from the launch list. It stays in the organization file. Only the user deletes
+>   an instance. These actions are `role.hire` and `role.fire`. They leave the hard waits and route
+>   under this requirement, within these bounds:
+>   - The chief acts only in its own organization.
+>   - The chief hires only role definitions that need no credentials, until a later version adds
+>     credentialed roles.
+>   - The chief hires only the role kinds its role file lists. Changing that list is a reviewed commit.
+>   - The chief hires only a role whose every action is on a fixed list of plain work actions: sending
+>     messages, writing records, asking for review, updating its assigned tasks, and the scope and
+>     working-push actions of an assigned task. A role holding any other action, such as launch, end,
+>     organization, naming, hire, review verdict or merge authority, or any action added later, is never
+>     hired. So the chief never hires a chief, never picks its own reviewers or merge gate, and the author
+>     is never the reviewer. This holds whatever the role file's list says. Adding to that list is a PRD
+>     change.
+>   - The chief may set a hired instance's model and narrow its limits, and nothing else about it.
+>   - The user can forbid per agent. The user marks an instance so the chief can't fire it, end its runs
+>     or change its model, and marks role kinds the chief can't hire. Only the user changes these marks, through the
+>     WebUI or the CLI.
+>   - The kill switch stops every hire and fire while it is on.
+>   - Every hire and fire is logged with the chief's instance, its run and the reason.
+
+Under "Landing", after REQ-LAND-1:
+
+> Added in version 1.7:
+>
+> - **REQ-LAND-2.** A coder pushes its own work to its own fork. The action is `git.push.remote`.
+>   - What it pushes: one commit, by its oid, never a ref name. That commit is the latest work commit the
+>     bus recorded for the coder's task, and the coder made that push. A decision that authorizes a push
+>     names that commit, and it doesn't authorize any other.
+>   - Where it lands: only the branch `refs/heads/<its Gitea user>/<branch>`. The host builds that
+>     name, the agent never does. A push never forces.
+>   - Which remote: the agent's own fork of the project's upstream. The business file names the upstream,
+>     and the host never contacts it. For each push the host builds the fork's address over https from
+>     the upstream's host, port and repository name and the agent's own Gitea user. The history check,
+>     the push and the credential match all use that address. So the agent's own user owns the receiving
+>     repository on every push, and the agent never names it.
+>   - The host refuses an upstream on a host or port other than the agent's Gitea, and an upstream the
+>     agent's own user owns. It refuses a fork that is missing, empty or doesn't share the project's
+>     history. Gitea's push-to-create stays off, so a push never creates a repository.
+>   - Who may: the action routes under REQ-DEC-2 and is granted within-role to the coder role only. No
+>     other role file grants it.
+>   - Before version 1.7 the action was a hard wait under REQ-WAIT-3, so each push needed a decision
+>     the human resolved, and that decision named the commit.
+>
+>   Every push is logged with the remote, the ref, the commit and, when one was given, the decision.
+
+Under "Credentials", after REQ-CRED-2:
+
+> Added in version 1.7:
+>
+> - **REQ-CRED-3.** An agent with a grant can run commands with sudo on another host. The agent asks
+>   for the host credential by name. The stack checks that a grant exists for that agent and that host
+>   before the credential is used. The agent never sees the key or any other secret value (REQ-CRED-1,
+>   REQ-VAR-2). An agent without a grant for that host is refused. Not every agent gets a grant. Who
+>   grants a host credential, and how, is set by the #424 design, which Jason approves.
+
+REQ-WAIT-3, appended:
+
+> `role.hire` and `role.fire` were added as hard waits and route under REQ-COS-3 since version 1.7.
+> `git.push.remote` was added as a hard wait and routes under REQ-LAND-2 since version 1.7.
+
+## Notes for the reviewer and for Mos
+
+- REQ-COS-1 (1.2) already says the chief "hires and terminates role instances". REQ-COS-3 gives that
+  sentence its actions and bounds. It doesn't widen REQ-COS-1.
+- The forbid now names what r3 called "replace": ending a kept instance's run with a reason and changing
+  its model (webby-0010 N2). A user-resolved decision still ends a kept run (row 194 D2.4).
+- The fixed list is `HIRE_ALLOWED` in row 194 D2.3, an allowlist since r4 (webby-0010 B1). r3's text
+  named the refused authorities instead, which let merge-gate and any later action through.
+- The kill switch is row 191's. If row 191 hasn't landed when this version is approved, the bound still
+  holds through row 194's chain on its candidate.
+- REQ-LAND-2 follows row 199's design r6 (4d3007ec9 on megavolt/row199, approved by Duckworth in
+  duckworth-0027: D9 to D11, D9a, D9c, Q-M1 and Q-M2, and the oid binding from mos-1034 item 5) and
+  Megavolt's wording in megavolt-0005, megavolt-0008 and megavolt-0014, through Sage (sage-1377,
+  sage-1380, sage-1387). The fork bullet answers duckworth B5 and B6 and webby-0011 N1. Commit-email
+  checks, the refusal codes and the URL parse rules (D9c) are host checks with tests in row 199, not
+  bounds, so they stay out of the text (megavolt-0008).
+- Once the routing lands and the decision is optional for the within-role class, the commit is the task's
+  latest recorded push at check time. It is still checked against the work ref tip and pushed by oid, so
+  the binding holds without a decision (megavolt-0008). Step 4 of "When this version lands" puts that in
+  the routing commit (duckworth-0022 N9, sage-1387).
+- REQ-LAND-2 and REQ-COS-3 meet at the coder. Coder declares Gitea credentials, so REQ-COS-3's
+  credentials bound keeps the chief from hiring one until a later version lifts it. `git.push.remote` isn't
+  on REQ-COS-3's fixed list either, so a coder holding it stays unhireable until a PRD version adds it
+  (row 194 D2.3).
+- Adding to the fixed action list is a PRD change (mos-1035 item 3, sage-1395). The role file's
+  `hireable` list stays a reviewed commit in `roles/`.
+- The credentials bound names no row number, so the text doesn't go stale when row 199 lands. A later
+  version lifts it.
+- REQ-CRED-3 states only what Jason said in Q183 and Q184 (sage-1422). It names the outcome and the
+  check, not how the stack reaches the host. Proxying the ssh and a signing socket are both designs, and
+  the #424 design picks one (duckworth-0038 B1).
+- Open point: Q183 doesn't say who grants host access or how, so the text leaves it open and defines no
+  mechanism. The #424 design settles it, Jason approves that design, and Duckworth reviews it because it
+  gives agents sudo on hosts (Q184, Mos's reading, duckworth-0038 B2). The build is row 210 (#1707,
+  owner Gizmoduck), a new row on top of row 199 (megavolt-0019, sage-1430).
+- This draft follows the PRD's own style: plain words, no semicolons in new sentences, and the status
+  paragraph never edited in place except to append.
@@ -0,0 +1,8 @@
+# Megavolt
+
+Builder seat, Claude Opus 5.5, started by Sage under mos-0974 and mos-0977 item 5 for MVP T1 item 6, the
+credential store per agent with its own git identity (#1697).
+
+No launcher in this directory. The seat runs as a T3 thread and works in its own worktree. It has no
+credentials of its own; until the credentials row settles per-agent identity, it pushes only its own `megavolt/*`
+branches through the repository credential helper (mos-0981), never `refactor`, `main` or another seat's branch.
@@ -0,0 +1,10 @@
+# Quackerjack
+
+Builder seat, Claude Haiku 5.5 at high effort, started by Sage under mos-1023 item 1 and Q177 for federation
+rows R5 (`mosaic access list, grant, revoke`) and R2 (the `federation` config key), per Gizmoduck's design
+section 7 (#414).
+
+No launcher in this directory. The seat runs as a T3 thread and works in its own worktree. It has no
+credentials of its own; until the credentials row settles per-agent identity, it pushes only its own
+`quackerjack/*` branches through the repository credential helper (mos-0981), never `refactor`, `main` or
+another seat's branch.
@@ -0,0 +1,36 @@
+# Row 189 gate timing (for row 197, Herb)
+
+Sage, 2026-10-20T19:25:04Z. Gate on 0c177e9ef (base 0217b71c8), one lane. The slot was mine. Seats may have run single test files at the same time, which the slot rules allow, and I did not record that.
+Start 2026-10-20T19:09:37Z, end 2026-10-20T19:20:36Z. Total wall time: 659 s.
+
+Wall time per suite is the gap between one suite's log mtime and the one before it (the first suite starts at start.txt), so it includes node start-up. node's duration_ms is listed where the suite prints it. Scripts print no duration.
+
+| Suite | Wall s | duration_ms s | Ended (UTC) |
+|---|---|---|---|
+| pkg-bus | 3 | 3.8 | 19:09:40 |
+| pkg-business | 3 | 2.2 | 19:09:43 |
+| pkg-cli | 388 | 388.5 | 19:16:11 |
+| pkg-control-board | 1 | 0.8 | 19:16:12 |
+| pkg-conversation | 35 | 35.4 | 19:16:47 |
+| pkg-discord | 3 | 2.6 | 19:16:50 |
+| pkg-harness | 12 | 11.6 | 19:17:02 |
+| pkg-ledger | 13 | 13.5 | 19:17:15 |
+| pkg-mosaic | 3 | 2.3 | 19:17:18 |
+| pkg-plugins | 0 | 0.3 | 19:17:18 |
+| pkg-project | 1 | 1.2 | 19:17:19 |
+| pkg-runs | 1 | 0.8 | 19:17:20 |
+| pkg-seat | 6 | 6.2 | 19:17:26 |
+| pkg-tasks | 1 | 1.2 | 19:17:27 |
+| pkg-webui | 58 | 57.9 | 19:18:25 |
+| script-auth | 1 | - | 19:18:26 |
+| script-conductor | 5 | - | 19:18:31 |
+| script-config | 2 | - | 19:18:33 |
+| script-discord | 8 | - | 19:18:41 |
+| script-extension-package | 1 | - | 19:18:42 |
+| script-foundation | 40 | - | 19:19:22 |
+| script-land-work | 11 | - | 19:19:33 |
+| script-queue | 21 | - | 19:19:54 |
+| script-release | 11 | - | 19:20:05 |
+| script-task | 31 | - | 19:20:36 |
+
+Source: /mnt/storage/scratch/sage-g189/out/*.log mtimes and gate.log. The cli suite is about 59% of the run, and webui plus conversation add about 14%.
@@ -0,0 +1,86 @@
+# Row 189: `stack-release.sh activate --no-send`
+
+Gitea #1687. Vikunja P19 #413 (Q175 interim, #412). Brief: docs/plans/2026-10-20_activate-no-send.md.
+Rulings: mos-0972 (the Console runs without `--send` until Q175 phase 2), mos-0973 (go; Sage builds,
+Dewey reviews; gate is the cli suite plus every scripts/test-*.sh). Base: def2e7932 (refactor, the
+brief commit on 9ae8c73ac).
+
+## What it does
+
+`activate ID BUSINESS --no-send` drops `--send` from `RUN_CONSOLE` in a new `send_for_target`, which
+`console_for_target` calls after `proof_for_target`. `install_stack` renders the unit from
+`RUN_CONSOLE` and `write_pointer` writes the pointer from it, so both lose the flag and `flags_drift`
+stays quiet afterwards. Only `activate` takes the flag; the parser sends every other op to usage
+(exit 4).
+
+`check_target` lets a `--no-send` activate name the pointer's copy only when the pointer's Console
+flags hold `--send`. That run is a live-copy re-pin, the same path row 187 uses for the proof pair:
+the plan prints the live-copy note, the run stops both units, backs up the stopped store and starts
+them again. A plain same-copy activate, or a same-copy `--no-send` once `--send` is gone, still
+refuses `already-active`.
+
+`--plan` prints one `send:` line after the `proof:` line, for activate and rollback:
+
+- `send: dropped; --no-send was given`
+- `send: off; --no-send was given and the pointer holds no --send`
+- `send: carried` (the pointer's `--send` goes on unchanged)
+- `send: off`
+
+The steps log gets `drop --send; --no-send was given`, or `--no-send was given and the pointer holds no
+--send, so there is nothing to drop`.
+
+Rollback and pm-on carry the pointer's flags as they are, so once `--no-send` has run, nothing adds
+`--send` back. There is no re-enable flag (mos-0973). Q175 phase 2 changes the Console flags in its
+own row.
+
+docs/TOOLS.md: `[--no-send]` in the usage block and one paragraph after the proof paragraph.
+
+## Tests (packages/cli/tests/stack-release.test.mjs, T55)
+
+1. Seeded preview pointer with `--send --tester-port 7333`: a same-copy `activate B acme --no-send`
+   passes. The pointer and the unit ExecStart lack `--send` and keep the other flags in order, status
+   says the unit flags match, the steps log has the drop line, the log line has from = to = B and the
+   backup sum equals the stopped store's, and the units stop and start in order.
+2. Plain same-copy activate, with `--tester-port` and with `--no-proof`, refuses `already-active`. So does
+   a same-copy `--no-send` once `--send` is gone, and on a pointer that never held it.
+3. The four `send:` lines, the live-copy note on the same-copy plan only, and the Console line right
+   after `send:` without `--send`. The run on a pointer with no `--send` logs the nothing-to-drop line
+   and no drop line.
+4. After `--no-send` on C1, a rollback to B leaves `--send` out of the pointer and the unit, the steps
+   log never names `--send`, and status matches. pm-on after `activate --pm-after-harness --no-send`
+   keeps it off.
+5. `--no-send` on rollback (with and without `--plan`), pm-on, status, adopt and rehearse is a usage
+   error with the usage text, nothing written, started or logged. The usage text shows `[--no-send]`.
+6. A pointer holding both the proof pair and `--send`: the plans for `--no-proof`, `--no-send` and both
+   name what each drops and carries. `--no-send` keeps the pair, `--no-send` with a new pair replaces it,
+   `--no-proof` keeps `--send`, and both together leave neither. Status matches after each.
+
+`planTail` gains `'send: off'` after `'proof: off'`, because every plan now prints the line. T36 takes
+`out.slice(-n)` around `planTail`, so its four slice counts grow by one.
+
+## Mutants
+
+mutants.sh in this packet, run on the candidate. Each mutates scripts/stack-release.sh and runs T55
+plus T1 and T2.
+
+- M1: the same-copy exception ignores `--no-send`.
+- M2: the same-copy exception allows `--no-send` without `--send` in the pointer.
+- M3: with `--no-send`, the pointer is written from `P_CONSOLE`, so it keeps `--send` while the unit
+  drops it.
+- M4: rollback re-adds `--send`.
+- M5: the parser accepts `--no-send` for rollback.
+
+Results: mutants-run.log, all five killed (M1 5 failures, M2 2, M3 7, M4 2, M5 2).
+
+## Deviations from the brief
+
+- The brief's line numbers were taken before row 163 landed. The candidate corrects them to the
+  9ae8c73ac lines (check_target :249-256, flags_drift :646-657, console_for_target :664-693, adopt
+  :828).
+- Test 5 also covers rehearse and `rollback --plan`, which the brief did not list.
+
+## Outbound calls
+
+None. The change edits an array before the existing unit render and pointer write. Every test uses
+the stand-in systemctl, units, stores and data root the file already builds; no test touches
+`~/.mosaic-dev`, the live units or a slot file.
@@ -0,0 +1,5 @@
+M1 KILLED fail=5
+M2 KILLED fail=2
+M3 KILLED fail=7
+M4 KILLED fail=2
+M5 KILLED fail=2
@@ -0,0 +1,34 @@
+#!/usr/bin/env bash
+# Row 189 mutants M1-M5: each mutates scripts/stack-release.sh in the sage-b189 worktree, runs T55 and
+# the plan-tail tests, and restores the file from a checked backup.
+set -uo pipefail
+WT=/mnt/storage/scratch/sage-b189
+OUT=/mnt/storage/scratch/sage-b189-mut/out
+S=$WT/scripts/stack-release.sh
+mkdir -p "$OUT" || exit 1
+cp -p "$S" "$OUT/stack-release.sh.orig" || { echo "backup failed"; exit 1; }
+ORIG=$(sha256sum "$S" | cut -d' ' -f1)
+[ "$(sha256sum "$OUT/stack-release.sh.orig" | cut -d' ' -f1)" = "$ORIG" ] || { echo "backup differs"; exit 1; }
+restore() { cp -p "$OUT/stack-release.sh.orig" "$S"; [ "$(sha256sum "$S" | cut -d' ' -f1)" = "$ORIG" ] || { echo "RESTORE FAILED"; exit 1; }; }
+trap restore EXIT
+
+mutate() {
+    case "$1" in
+        M1) sed -i '/{ \[ "\$NO_SEND" = 1 \] && \[\[ " \${P_CONSOLE\[\*\]} " == \*" --send "\* \]\]; } ||/d' "$S" ;;
+        M2) sed -i 's/{ \[ "\$NO_SEND" = 1 \] && \[\[ " \${P_CONSOLE\[\*\]} " == \*" --send "\* \]\]; } ||/{ [ "$NO_SEND" = 1 ]; } ||/' "$S" ;;
+        M3) sed -i 's/^    write_pointer "\$TO" "\$RUN_PM" "\$RUN_PENDING" "\$P_CLAUDE" "\$T_SCHEMA" "\${RUN_CONSOLE\[@\]}"$/    if [ "$NO_SEND" = 1 ]; then write_pointer "$TO" "$RUN_PM" "$RUN_PENDING" "$P_CLAUDE" "$T_SCHEMA" "${P_CONSOLE[@]}"; else write_pointer "$TO" "$RUN_PM" "$RUN_PENDING" "$P_CLAUDE" "$T_SCHEMA" "${RUN_CONSOLE[@]}"; fi/' "$S" ;;
+        M4) sed -i 's/^        SEND_PLAN="send: off"$/        SEND_PLAN="send: off"; [ "$OP" != rollback ] || RUN_CONSOLE+=(--send)/' "$S" ;;
+        M5) sed -i 's/--no-send) \[ "\$OP" = activate \] || usage;/--no-send) { [ "$OP" = activate ] || [ "$OP" = rollback ]; } || usage;/' "$S" ;;
+    esac
+}
+
+for m in M1 M2 M3 M4 M5; do
+    restore
+    mutate "$m"
+    if [ "$(sha256sum "$S" | cut -d' ' -f1)" = "$ORIG" ]; then echo "$m NOT-APPLIED"; continue; fi
+    bash -n "$S" || { echo "$m SYNTAX"; continue; }
+    diff "$OUT/stack-release.sh.orig" "$S" > "$OUT/$m.diff"
+    (cd "$WT" && TMPDIR=/mnt/storage/scratch/t189 timeout 900 node --test --test-reporter=tap --test-name-pattern='T55|T1 |T2 ' packages/cli/tests/stack-release.test.mjs) > "$OUT/$m.log" 2>&1
+    fails=$(awk '/^# fail /{print $3}' "$OUT/$m.log")
+    if [ "${fails:-0}" -gt 0 ]; then echo "$m KILLED fail=$fails"; else echo "$m SURVIVED"; fi
+done
@@ -1363,3 +1363,5 @@ are never rewritten or removed; corrections are new entries.
 2026-10-20T18:41:20Z | Filbert (Opus 5.5, 048f3c63) | Q175 SSO design D1/D2 check (DESIGN.md blob eba861f5d2bb at d55d86bb0), static git diff 817e8f51b..d55d86bb0 | ack: D1 and D2 match; design approved; Mos C1 sequence confirm still open; no Gitea/queue record
 2026-10-20T18:57:10Z | Filbert (Opus 5.5, 048f3c63) | row 190 design review r2 (#1688, DESIGN.md sha256 5493c9df3ec0) | CHANGES to Darkwing, cc Sage: B1 claim check on MOSAIC_CONFIG-only selection, B2 shared prefix drop-in dirs; N1-N7 notes; static read, no slot, no Gitea or queue record
 2026-10-20T19:00:04Z | Filbert (Opus 5.5, 048f3c63) | row 190 design review r3 (#1688, DESIGN.md sha256 98236a1aff98) | APPROVE to Darkwing, cc Sage: B1 and B2 closed with M13 and M14, N7 settled by Sage's 48ebee0ff; static read, no slot; manifest round gets a queue review record (sage-1337)
+2026-10-20T20:40:15Z | Filbert (Opus 5.5, 048f3c63) | row 190 (#1688) manifest round 1 review, candidate 8862feccc (static) | CHANGES: B1 base drift, row 189 ace27dc5e conflicts in stack-release.sh, rebase + full gate rerun; N1-N7 notes; Gitea 29634, queue rev 2362 (uncommitted, left for Sage)
+2026-10-20T21:29:20Z | Filbert (Opus 5.5, 048f3c63) | row 190 (#1688) manifest round 2 review, candidate 537a02392 (static) | CHANGES: B1 base drift, row 192 4429a104f conflicts in mosaic-config.mjs and webui-service.sh (async load); round 2 content fine; Gitea 29685, queue rev 2447 (uncommitted, left for Sage)
@@ -15,7 +15,7 @@ and changes nothing.

 | Command | Purpose | Notes |
 |---|---|---|
-| `scripts/bootstrap.sh` | Create `~/.config/mosaic-dev/config.json` if absent | Idempotent; existing config validated, never rewritten |
+| `scripts/bootstrap.sh [--instance NAME]` | Create `~/.config/mosaic-dev/config.json` if absent; with `--instance NAME`, `~/.config/mosaic-NAME/config.json` and the claimed root `~/.mosaic-NAME` | Idempotent; existing config validated, never rewritten. See [Stack instances](#stack-instances---instance-name-row-190) |
 | `scripts/build.sh` | Build the release image | Tag derived from `RELEASE` + pinned pi version |
 | `scripts/hello.sh` | One-shot startup request | Prints model response on stdout |
 | `scripts/verify.sh` | Full gated test | Exit 0 only on exact `MOSAIC_HELLO_OK`; `EXPECTED_MARKER` overrides for negative drills |
@@ -270,9 +270,9 @@ scripts/mosaic follow --thread <thread> [--tester]
 scripts/mosaic stop <run>
 scripts/mosaic launches off | on [--business <id>]
 scripts/mosaic launches list [--json]
-scripts/bus-service.sh render [--copy ID [--copies DIR]] [--pm] [--claude PATH]
-scripts/bus-service.sh install [--copy ID [--copies DIR]] [--pm] [--dir DIR] [--no-reload] [--claude PATH]
-scripts/bus-service.sh uninstall | status <business>
+scripts/bus-service.sh [--instance NAME] render [--copy ID [--copies DIR]] [--pm] [--claude PATH]
+scripts/bus-service.sh [--instance NAME] install [--copy ID [--copies DIR]] [--pm] [--dir DIR] [--no-reload] [--claude PATH]
+scripts/bus-service.sh [--instance NAME] uninstall | status <business>
 ```

 The human commands read and resolve through the broker's human transport
@@ -321,12 +321,89 @@ stdin and stdout it exits 4 with the usage.
 Exit codes: `0` ok · `1` failed or outcome unknown · `2` invalid input ·
 `3` refused or config problem · `4` usage. Details: `packages/cli/README.md`.

+## Stack instances (`--instance NAME`, row 190)
+
+Several stacks can run on one host, each with its own config, data root,
+units, Console port and CLI wrapper. The default instance is today's stack
+and keeps every name it had. A named instance is created once:
+
+```
+scripts/bootstrap.sh --instance NAME
+```
+
+NAME matches `^[a-z][a-z0-9]{1,15}$`; anything else exits 4
+(`instance-name-invalid`), and `--instance dev` is the default. Bootstrap
+writes `~/.config/mosaic-NAME/config.json` (0644) and claims `~/.mosaic-NAME`
+with the marker `instance.json`, `{"instanceVersion":1,"name":"NAME"}`. It
+creates either directory 0700; one that already exists keeps its mode. It refuses with exit 3 and writes
+nothing when the root exists, is not empty and holds no marker naming NAME.
+A second run changes nothing. `~` is the home of the OS user that runs the
+instance.
+
+`--instance NAME` is taken, once and in any position, by `bootstrap.sh`,
+`bus-service.sh`, `webui-service.sh` (all but `copy`), `discord-service.sh`,
+`stack-copy.sh` (`wrapper` and `check`) and `stack-release.sh`. Copies serve
+every instance, so both `copy` verbs refuse it with exit 4. Inside a process the config
+travels as `MOSAIC_CONFIG`. Selection, checked before any read or write:
+
+| Given | Config | Names |
+|---|---|---|
+| neither | `~/.config/mosaic-dev/config.json` | the default's |
+| `MOSAIC_CONFIG` only | that file | the default's |
+| `--instance NAME` only | `~/.config/mosaic-NAME/config.json` | NAME's |
+| both | must be one file (a symlink to it agrees), else exit 4 `instance-config-mismatch` | NAME's |
+
+Every selection checks the data root's marker. A named instance whose root
+lacks its own marker refuses `instance-root-unclaimed`; a root whose marker
+names another instance refuses `instance-root-mismatch`, also when a config
+reaches it with no flag. Both exit 3 before anything is read or changed. A
+missing config exits 3 with the bootstrap command that creates it.
+
+| | Default | Instance NAME |
+|---|---|---|
+| bus unit | `[email protected]` | `[email protected]` |
+| Console unit | `mosaic-webui.service` | `mosaic-webui-NAME.service` |
+| Discord unit | `[email protected]` | `[email protected]` |
+| CLI wrapper | `$BIN/mosaic` (Q81 marker) | `$BIN/mosaic-NAME`, marker `# mosaic-cli wrapper, instance NAME (row 190)`, exports `MOSAIC_CONFIG` |
+| bus session env | `%h/.config/mosaic-dev/secrets/claude-session.env` | `~/.config/mosaic-NAME/secrets/claude-session.env` |
+| Console port | `--port`, 7332 when absent | `--port` required; 7330, 7332 and 7333 exit 4 `port-reserved` |
+
+A named instance's units add `Environment=MOSAIC_CONFIG=<its config>` and
+` [NAME]` after the Description, and the Console unit's comment on the
+variables it sets names `MOSAIC_CONFIG`. The default's renders are
+byte-identical to the templates' renders before row 190. `stack-copy.sh
+wrapper --instance NAME` creates `$BIN/mosaic-NAME` or replaces one that
+carries NAME's marker, and refuses any other file. `check --instance NAME`
+needs `--business ID`, and fails with `CLI: <copy> (MOSAIC_CONFIG mismatch)`
+when the wrapper does not export NAME's config.
+
+For every instance, a Console `--port` or `--tester-port` that another
+installed Console unit in the unit directory already takes refuses
+`port-claimed`, naming that unit: `webui-service.sh install` exits 1, and
+`stack-release.sh activate` and `rollback` exit 3 before anything stops
+(`--plan` lists it). A unit with no `--port` holds 7332.
+
+`stack-release.sh --instance NAME` reads only NAME's pointer, log, store and
+backups. Its busy check sees only NAME's bus units. Its drop-in scan adds
+`mosaic-bus-NAME@*.service.d` and the shared `mosaic-bus-.service.d`. Its
+rollback set holds NAME's two unit files, their own `.d` directories and
+`$BIN/mosaic-NAME`; it never captures or restores the shared prefix
+directories (`mosaic-bus-.service.d`, `mosaic-webui-.service.d`,
+`mosaic-discord-.service.d`). The live-session guard refuses a path inside
+any named instance's config directory or `~/.mosaic-NAME`, even when that
+instance's config is unreadable.
+
+All instances run under one OS user for now. That user's processes can
+read and control every instance; a separate user per instance is row 195.
+A real second instance on this host is a Q173 window, and tunnel or Traefik
+exposure of a named Console waits for Jason after Q175 SSO.
+
 ## Stack copies (`scripts/stack-copy.sh`)

 ```
 scripts/stack-copy.sh copy COMMIT [--copies DIR] [--allow-worktree]
-scripts/stack-copy.sh wrapper ID [--copies DIR] [--bin DIR]
-scripts/stack-copy.sh check [--copies DIR] [--bin DIR] [--business ID]
+scripts/stack-copy.sh wrapper ID [--instance NAME] [--copies DIR] [--bin DIR]
+scripts/stack-copy.sh check [--instance NAME] [--copies DIR] [--bin DIR] [--business ID]
 ```

 One read-only tree supplies the bus, Console and human CLI (row 85,
@@ -368,11 +445,11 @@ reports checkout or copy identity and refactor drift, and writes nothing.
 ```
 scripts/stack-release.sh adopt BUSINESS
 scripts/stack-release.sh activate ID BUSINESS [--pm | --pm-after-harness] [--migrate] [--tester-port N]
-    [--proof-header NAME --proof-file PATH | --no-proof] [--timeout S] [--plan]
+    [--proof-header NAME --proof-file PATH | --no-proof] [--no-send] [--timeout S] [--plan]
 scripts/stack-release.sh pm-on BUSINESS [--timeout S]
 scripts/stack-release.sh rollback BUSINESS [--restore ACTIVATION [--events N]] [--timeout S] [--plan]
 scripts/stack-release.sh status BUSINESS
-common options: --copies DIR, --bin DIR
+common options: --copies DIR, --bin DIR, --instance NAME
 --events N is the total of the per-table counts the post-backup-events refusal prints: events and
 every table in COUNTED.
 ```
@@ -480,6 +557,14 @@ copies. It checks the file with `stat` and `realpath` and never reads the value.
 or `off`. On the live copy it also notes that the run re-pins the pointer's copy
 and only the Console flags change.

+`activate ... --no-send` (row 189, mos-0972) drops `--send` from the pointer's
+Console flags and the unit, so the Console serves reads and no human sends. It
+may name the live copy while the pointer holds `--send`; once `--send` is gone a
+same-copy `--no-send` refuses `already-active`. Later activates, `pm-on` and
+rollbacks carry the pointer, so send stays off. No flag puts `--send` back.
+`--plan` prints one `send:` line: `dropped`, `off` with or without the
+`--no-send` note, or `carried`.
+
 #### A target past c216f47db: the PM after the harness kind

 From c216f47db on, the bus launches the PM only with a `harness` kind in the
@@ -594,6 +679,7 @@ its runs alone. No unit passes it, and `--pm` with it is a usage error.

 ```bash
 scripts/webui-service.sh copy COMMIT [--copies DIR]        # make a pinned copy
+# render, install, uninstall and status also take --instance NAME (row 190); copy refuses it (exit 4)
 scripts/webui-service.sh render [--copy ID [--copies DIR]] [FLAGS]   # print the unit
 scripts/webui-service.sh install --copy ID [--copies DIR] [--dir DIR] [--no-reload] [FLAGS]
 scripts/webui-service.sh uninstall [--dir DIR] [--no-reload]
@@ -671,8 +757,9 @@ Each value is held to a plain character set the unit can carry (no space,
 `%`, `$`, quote, backslash, `&` or `|`), and the preview values must start
 with a letter or digit; anything else is refused. With `--auth-header
 X-authentik-uid`, in any letter case, `--allow-user` must be the Authentik
-uid, `^[0-9a-f]{64}$` (lead decision 101). The unit sets no `MOSAIC_*`,
-`CLAUDE*`, `CODEX*` or `PI_*` variable. Serve's exit 2 (usage, config, or a
+uid, `^[0-9a-f]{64}$` (lead decision 101). The default's unit sets no `MOSAIC_*`,
+`CLAUDE*`, `CODEX*` or `PI_*` variable; a named instance's sets only
+`MOSAIC_CONFIG` (row 190). Serve's exit 2 (usage, config, or a
 port already in use) is not restarted.

 The update/rollback sequence is [Pinned stack update](#pinned-stack-update)
@@ -697,7 +784,7 @@ scripts/discord.sh stop  <binding>
 scripts/discord.sh unlock <binding>
 scripts/discord.sh recover <binding>
 scripts/discord.sh reload <binding>
-scripts/discord-service.sh render | install [--dir DIR] [--no-reload] | uninstall [--dir DIR] [--no-reload] | status <binding>
+scripts/discord-service.sh [--instance NAME] render | install [--dir DIR] [--no-reload] | uninstall [--dir DIR] [--no-reload] | status <binding>
 ```

 One seat's conversation reachable from listed channels of one Discord
@@ -1,7 +1,8 @@
 # Brief: activate --no-send drops the Console's --send

 Sage, 2026-10-20, for Mos's ruling mos-0972 (Q175 interim, Vikunja #412). Owner Sage, reviewer Dewey, gate owner
-Sage. Base: refactor 9ae8c73ac (row 163 landed). Line numbers are at that commit.
+Sage. Base: refactor 9ae8c73ac (row 163 landed). Line numbers are at that commit. The candidate corrects them;
+the first draft took them before row 163.

 This row builds the tool only. The live restart without `--send` is a separate step afterwards, a same-copy
 activate under Q173 with a backup first and a STATE report after. No test here touches `~/.mosaic-dev`, the
@@ -14,11 +15,11 @@ Mos ruled that the Console runs without `--send` until Q175 phase 2, because wit
 process can forge `X-authentik-username` on 127.0.0.1:7332 and send as Jason (design section 8). On the pinned
 stack, the Console flags live in the pointer (`~/.mosaic-dev/state/stack-active.json`):

- `console_for_target` (scripts/stack-release.sh:658-687) carries the pointer's flags unchanged. Only
+- `console_for_target` (scripts/stack-release.sh:664-693) carries the pointer's flags unchanged. Only
  `--tester-port` and the row 187 proof pair can change.
- `check_target` (:247-249) lets an activate name the pointer's copy only for a proof-pair change.
- `adopt` refuses once a pointer exists (:822).
- A hand `webui-service.sh install` without `--send` makes `flags_drift` (:640-651) refuse
+- `check_target` (:249-256) lets an activate name the pointer's copy only for a proof-pair change.
+- `adopt` refuses once a pointer exists (:828).
+- A hand `webui-service.sh install` without `--send` makes `flags_drift` (:646-657) refuse
  `unit-flags-drift` on every later activate, pm-on and rollback.

 So the tool can't drop `--send` today. This row adds that one path.
@@ -0,0 +1,57 @@
+# Brief: a credential store per agent, own git identity, pushes to a remote
+
+Sage, 2026-10-20, for mos-0974 (MVP T1 item 6) and the MVP plan
+(`jason-master-restart/projects/mosaic-mvp/PLAN.md` item 6, GAP-MAP G11 and G13; TARGET.md: "credentials store
+available for all agents; secrets protected with RLS equivalent" and "Agent uses own credentials for git and
+other actions"). Gitea #1697. Owner Megavolt (Opus 5.5, a new builder seat), reviewer Duckworth, gate owner
+Sage. Base: refactor at the brief commit. Design first. The first deliverable is
+`agents/megavolt/work/queue-ROW/DESIGN.md`.
+
+This row draws a security boundary. Sage reviews the design's authority model, and Mos rules on it before any
+code is written.
+
+## What exists today (GAP-MAP, measured at 9ae8c73ac)
+
+- G11. Credential references exist per instance for Gitea and Vikunja only
+  (`packages/business/src/credentials.mjs`, `packages/bus/src/credentials.mjs`, `vocabulary.mjs:103`). One
+  Claude env file is shared by every seat.
+- G13. Agents use their own Vikunja token (`packages/tasks/src/adapter.mjs`). Git goes through the host
+  socket (`packages/cli/src/git-socket.mjs`). Gitea tokens are loaded but never used.
+- The development repository's helper (`scripts/git-credential-mosaic.mjs`, wired in `.git/config` for
+  git.mosaicstack.dev) pushes as one identity. Until this row lands, seats push only their own `<seat>/*`
+  branches through it (mos-0981).
+
+## What the design must settle
+
+1. The store. Where each agent's credentials live, per instance, under the row 190 config canon. File modes,
+   ownership and the read path. Which process may read which entry, and how the bus enforces that (the "RLS
+   equivalent"). A process asking for another agent's entry is refused and logged.
+2. Kinds. Gitea (git over HTTPS, and the API), Vikunja, and the model provider. Say which kinds 10-27 needs
+   and which wait. The model provider entry must not copy jwoltje's `claude-session.env`. If it needs a new
+   provider account or subscription, flag it for Jason and don't pick one.
+3. Git identity and push. Each agent commits with its own name and email and pushes with its own token to a
+   remote it is granted. Which refs an agent may push (its own branches, never the default branch or another
+   agent's), and where that's enforced: the Gitea side (branch protection, token scopes) and our side. How
+   this fits the host git socket, or replaces it.
+4. Lifecycle. Issue, rotate (`rotateBy`, `expires`), revoke and delete, and what row 194 (agent lifecycle) calls
+   when an agent is hired or fired. A fired agent's credentials stop working at once.
+5. Who does what. Creating a Gitea user or token, or any account outside the fleet, is Jason's (Q173
+   exclusions). The design lists each such step as a command or UI action for Jason. Agents never mint
+   accounts.
+6. Migration. Today's seats (jarvis helper, seat tokens) keep working until each moves. The mos-0981 push
+   rule ends only when Mos says so.
+7. What this row closes in G11 and G13, and what stays open.
+
+## Boundaries
+
+- No credential value is read, printed, logged or committed. Tests use fake tokens in scratch roots and a
+  fake Gitea.
+- No change to `~/.mosaic-dev`, `~/.config/mosaic-dev`, the live units, slot files, `~/.mosaic` or the live
+  `.git/config` of the canonical checkout.
+- No request to git.mosaicstack.dev, tasks.woltje.com or any provider from a test.
+
+## Gate
+
+Duckworth approves DESIGN.md, Mos rules on the authority model, then Duckworth approves the manifest. The bus,
+business, cli and tasks suites and every `scripts/test-*.sh` are green on Sage's gate, and the design's
+mutants are killed.
@@ -0,0 +1,120 @@
+# Federation build rows R1, R2 and R5 (#414)
+
+Sage, 2026-10-20, for Mos's orders mos-1023 item 1, mos-1028 item 2 and mos-1034 item 1. The design is
+Gizmoduck's `agents/gizmoduck/work/federation/DESIGN.md` at a1daa3c07 on `gizmoduck/federation-design` (r4.9,
+sha256 a31cbebd070f9e3a5ca4ccb158b1747c6f5a83c3469855705b0026a581fb5c6a). Duckworth approved r4.5
+(duckworth-0012), r4.6, r4.7 (duckworth-0020) and r4.8 (duckworth-0021, 8a22d0897 on `duckworth/reviews`),
+and acked r4.9 (duckworth-0024). r4.7 applies Jason's Q181 hosts, r4.8 adds N22's R8 checks and r4.9 names who
+runs them. None of them changes R1, R2 or R5. Section 7's table
+sets each row's scope and test gate. Vikunja P19 #414. Seats push only their own `<seat>/*` branches
+(mos-0981).
+
+The other R rows are filed when their parents have candidates: R3 after R1 and row 196, R4 after R3, R5 and
+row 193's viewer level (193a, mos-1019), R6 after #412 phase 1, R1, R2 and R3, R7 after R1-R6 and row 190.
+R8 is a live window, not a code row. Its brief is the last section here.
+
+## Brief: FED R1, the access.json loader and validator
+
+Owner Gizmoduck, reviewer Duckworth, gate owner Sage. Base: refactor at this brief's commit. No parent.
+
+`packages/business/src/access.mjs`: the access.json loader and validator from DESIGN.md section 3.5, and the
+pure `covers`. Providers, peers and businesses come in as arguments. One read plus the file checks. The
+exported interface is what R5 and row 193a build against, so the manifest names it, and any change to it in
+review goes to Sage before it lands. Section 7 names `covers` but not the loader and validator exports or
+the context shape. Morgana's 193a (508ee4d61 on `morgana/row193a`) assumes `checkAccess(doc, {providers,
+peers, businesses})`, with `businesses` mapping an id to `{human, instances}`, throwing a `BusinessError` that
+names the key path. Use those names, or tell Morgana and Quackerjack yours before the manifest goes to
+Duckworth. Row 193a later widens the level check to `viewer` on R1's candidate (mos-1019).
+
+Tests, in `packages/business/tests/`: every rule in 3.5 refuses with the key path named. That covers a
+symlink, a non-regular file, another owner, group or other write, expiry, `*`, a grant disjoint from the given
+subjects, `human` and `tester` ids, any level other than `collaborator`, and a project entry that isn't a
+UUID. For `covers`: `*` and listed ids match, while an unlisted project, instance or business doesn't, an
+expired grant doesn't, and a level filter rejects another level. One mutant per refusal, each killed.
+
+Boundaries: no change to `~/.mosaic-dev`, `~/.config/mosaic-dev`, the live units or any live access.json. Tests
+use scratch roots. Single test files run freely, and suites need Sage's slot.
+
+Gate: Duckworth approves the manifest. The business suite and every `scripts/test-*.sh` are green on Sage's
+gate, and the mutants are killed.
+
+## Brief: FED R5, mosaic access list, grant and revoke
+
+Owner Quackerjack, reviewer Duckworth, gate owner Sage. Chained on R1 (Q177). The build starts now against
+R1's exported interface as the R1 manifest names it, and R5 lands after R1 and rebases onto R1's landing.
+
+`mosaic access list`, `grant` and `revoke`: human proof, atomic write, revision bump, a receipt line. The help
+text states the `instances` limit and the provider-removal order (DESIGN.md section 7, row R5). R4 later makes
+these verbs call `access.reload`, so R5 leaves no other reload path.
+
+Context (sage-1419). `ssoSubjects` is row 192's `console.sso.providers[].subjects` flattened to `{provider,
+sub}` pairs; the design's "`console.sso.subjects`" in 3.5 is shorthand for it. `providers` is the list of
+`providers[].id`, read through `loadSystem` and row 192's `checkConsole`. `peers` is `[]` until R2 lands, so a grant
+naming a peer home refuses. R5 rebases onto row 192's landing as well as R1's.
+
+Tests, in `packages/cli/tests/`: tester and agent callers are refused, a concurrent write refuses on a
+revision conflict, the receipt line is appended, and a bad grant is refused before anything is written. One
+mutant per refusal, each killed.
+
+Boundaries: no change to `~/.mosaic-dev`, `~/.config/mosaic-dev`, the live units or any live access.json. The
+human proof in tests uses the scratch stand-in pattern (a scratch bus verifies its own human-cli path).
+Single test files run freely, and suites need Sage's slot.
+
+Gate: Duckworth approves the manifest. The cli suite and every `scripts/test-*.sh` are green on Sage's gate,
+and the mutants are killed.
+
+## Brief: FED R2, the federation key in the system config
+
+Owner Quackerjack, reviewer Webby, gate owner Sage. Chained on row 192 (#412 phase 1). The build starts when
+row 192 has a candidate, on that candidate.
+
+A `federation` key in `scripts/mosaic-config.mjs` with the shape in DESIGN.md section 3. A config with no
+`federation` key still loads as it does today. This changes the config schema, so the manifest lists every
+reader of the key.
+
+Tests, in `scripts/test-config.sh`: a valid key loads, an unknown sub-key and a bad origin refuse, and a
+config without the key loads. One mutant per refusal, each killed.
+
+Boundaries: `~/.config/mosaic-dev/config.json` is user-authored and is not touched. Tests use scratch config
+dirs only.
+
+Gate: Webby approves the manifest. The cli suite and every `scripts/test-*.sh` are green on Sage's gate, and
+the mutants are killed.
+
+## Brief: FED R8, the hub window on 10.1.1.54
+
+A live window, not a code row (DESIGN.md section 7, row R8). The brief follows r4.11, b93f098f0 on
+`gizmoduck/federation-design` (sha256 1bcee8df0a3a8628a6646535b756c936ca6d9e7bcfa7e1dd2bf1d3f01715c8e6),
+which Duckworth acked with r4.10 (duckworth-0034). Mos closed design rounds there (mos-1072). Run by Jason and
+Mos. Nothing here authorizes a step on any host; each step waits for the window's go.
+
+What changed since r4.9 (DECISIONS Q182, Q183, mos-1055, mos-1063). R8 is a recorded acceptance. It starts
+with Jason's acceptance of the factory paths to .54 on record, quoted in section 8. The privilege and host
+checks still run, and each result goes into the R8 record with the name of whoever ran it. They report and
+don't refuse. The four functional checks named at the end of section 7's R8 row still stop R8 when they fail
+(mos-1066 item 1).
+
+Order (mos-1042 item 2). R8 runs after the Case 2 install on .54 (#416, due by 2026-10-27, Jason's latest-by
+date in Q176, mos-1069), after Bean and Chet are live in Case 2, and after both Hermes gateways on 10.1.1.54
+have stopped. Case 2 go-live doesn't wait on R8. The risk, stated for 10-27: federation between the two
+instances depends on Melanie's switch-over date.
+
+Entry checks, all before anything starts:
+- R7, #412 phase 2 and Jason's #419 answer, as section 7 lists.
+- The four hub user checks on 10.1.1.54 (N22, mos-1035 item 1): `sudo -l -U mosaic` grants nothing, `id
+  mosaic` shows only its own group, `~mosaic/.ssh/authorized_keys` is absent or empty, and no file under
+  `/etc/sudoers.d` names `mosaic`. An agent or Jason runs them as localadmin (mos-1055), and the output goes
+  into the R8 record with who ran them.
+- The factory privilege checks, the key fingerprint comparison and the section 8 privilege path table, each
+  as section 7's R8 row states them.
+
+Build notes:
+- N1 (Duckworth, duckworth-0034, mos-1072). A check that fails on a path Jason didn't name in Q182 or Q183 is
+  marked "not named in Q182 or Q183" in the record, not filed under the acceptance. Examples: a factory mount
+  of hub data, another agent on .54, a provider admin token. Mos takes each one to Jason.
+- N2 (Duckworth, doc-only). The Q183 and Q4 quotes in section 8 are excerpts. When the R8 record quotes them,
+  it marks each omission with "…" and checks the full text at DECISIONS.md:1535-1541 in jason-master-restart
+  (read only).
+
+Done when every entry check has its output recorded, Jason signs in to the hub and sends one message, Melanie
+revokes, and his next request is refused.
@@ -0,0 +1,81 @@
+# Brief: a pre-push hook that refuses force-pushes, and a busy check that fails on BUSY (#426)
+
+Sage, 2026-10-20, for Mos's order mos-1078 (Vikunja P19 #426) and its go mos-1083 item 1. Owner Rocko,
+reviewer Dewey, gate owner Sage. Base: refactor at this brief's commit. Starts after row 191.
+
+## Why
+
+Morgana force-pushed a seat branch on 2026-10-20 (morgana-0016). Mos took it to Jason. Force-push is a
+Q173 exclusion, and canon says never force-push, but nothing mechanical stops one. Mos: "Done means a
+force-push from a seat worktree is refused, with a test that shows it."
+
+Earlier the same day, a busy check chained as `| tail -1 &&` passed while the slot was BUSY. The script it
+called prints BUSY or CLEAR, but it exits 0 either way.
+
+The guard has two layers:
+- (a) Gitea protection with force-push off on seat branch patterns and on refactor, next and main. ops-01
+  sets it up, through Mos (mos-1082). That part isn't this row.
+- (b) The client hook below. It can be bypassed with `--no-verify`, so (a) is the real guard and (b) is the
+  early refusal.
+
+## What ships
+
+1. `scripts/git-hooks/pre-push` (new). For each ref line git passes on stdin:
+   - It refuses when the remote sha isn't all zeros and isn't an ancestor of the local sha (`git
+     merge-base --is-ancestor`). The refusal names the ref and both shas, and the hook exits 1.
+   - A new branch passes. A delete (local sha all zeros) is refused.
+   - Any failure of the check refuses too, for example an unknown remote object. The hook fetches nothing.
+     If the remote tip isn't present locally, it refuses and says to fetch first.
+2. Install, following `scripts/queue-commit.sh --install-hook`. Either add a `--install-push-hook` there or
+   ship a small `scripts/install-git-hooks.sh`, whichever fits the existing code better. Say which in BUILD.md.
+   - The install copies the hook into the common `.git/hooks`, which every seat worktree shares.
+   - It refuses when `core.hooksPath` is set (the husky trap, 2026-10-09). It refuses when an installed
+     pre-push differs from the repository copy, unless `--force-install` is given.
+   - It never edits the installed copy in place.
+3. `scripts/slot-busy.sh` (new), the shared busy check.
+   - It prints one BUSY line per matching process, or CLEAR.
+   - It exits 0 on CLEAR, 1 on BUSY and 2 on its own error.
+   - It matches `node --test`, `gate.sh`, `mutant`, `scripts/test-*.sh` and `docker compose` command lines.
+     It skips its own process and shell snapshots.
+   - It reads `/proc/<pid>/cmdline` and the cwd link only, never file contents under another seat's
+     directory.
+   - Usage in `docs/TOOLS.md`: `bash scripts/slot-busy.sh > LOG && gate`, with `set -o pipefail` in any
+     script that pipes it. Never `| tail -1 &&`.
+
+## Tests
+
+Add them to `scripts/test-land-work.sh` or a new `scripts/test-git-guard.sh` (say which). Run against a scratch
+bare remote and a scratch clone with a worktree, never against origin:
+- A rewritten branch pushed with `--force` from a worktree is refused, and the remote ref is unchanged.
+- A `+refspec` push is refused.
+- A fast-forward push passes.
+- A new branch passes.
+- A delete is refused.
+- A remote tip that's missing locally is refused.
+- The install refuses with `core.hooksPath` set, and refuses a differing installed hook.
+- `slot-busy.sh` exits 1 with a fake `node --test` process running (a sleeping stand-in with that argv),
+  and 0 without one.
+- `slot-busy.sh | tail -1 && false` doesn't apply here. The test runs `bash scripts/slot-busy.sh >/dev/null
+  && echo ran`, and asserts it doesn't print `ran` while BUSY.
+
+Mutants, each killed:
+- drop the ancestor check
+- treat an unknown remote object as passing
+- let a delete pass
+- install over a set `core.hooksPath`
+- `slot-busy.sh` exits 0 on BUSY
+
+## Boundaries
+
+- Install the hook in the canonical checkout only after landing, as its own step with Sage. Tests use
+  scratch repositories.
+- No push to origin from a test. No change to Gitea config. That's ops-01's.
+- Don't touch `~/.mosaic`, `~/.mosaic-dev` or `~/.config/mosaic-dev`.
+
+## Gate
+
+Dewey approves the manifest. The new or changed `scripts/test-*.sh` file and every other `scripts/test-*.sh`
+are green on Sage's gate, and the mutants are killed. Done when the hook is installed in the canonical
+checkout and a scripted force-push from a seat worktree to a scratch remote is refused there. ops-01's
+server proof (a refused force-push, plus a fast-forward push and a new branch that go through) is recorded
+in Vikunja #426 by Mos.
@@ -0,0 +1,70 @@
+# Brief: agent host access with sudo through the credential store (#424)
+
+Sage, 2026-10-20, for Jason's rulings Q183 and Q184 relayed by Mos (mos-1056 item 3, mos-1067). Gitea #1707, Vikunja P19
+#424, due 2026-10-27 (Q184: "Q5: by 10.27"). Owner Gizmoduck (design and build), reviewer Duckworth, gate owner
+Sage. Chained on row 199's candidate (Q177): row 199 design r6 (4d3007ec9 on `megavolt/row199`, approved in
+duckworth-0027) is not reopened. This row lands after 199 and rebases onto its landing.
+
+## What Jason asked for
+
+Q183, through Mos: "I envision a credential store within Mosaic Stack that works as some sort of variable for
+the agent to call. The system will enforce access to the credentials to keep the agents sandboxed with proper
+security... If we can utilize the credential store in Mosaic Stack and allow agents to perform their jobs with
+NOPASSWD sudo on various machines, I am a happy man." Q183 also says not every agent needs that access.
+
+Mos's requirements (mos-1067 item 1):
+- An agent asks for a host credential by name.
+- The stack checks a grant for that agent and that host, and does the ssh and sudo for it.
+- The agent never sees the key or any secret value.
+- Only agents with a grant can do it.
+
+The PRD text is REQ-CRED-3, drafted by Honker for PRD 1.7 (sage-1422). If it misses 1.7 it goes into 1.8, and
+this row lands only after the version that holds it is approved.
+
+## What row 199 gives and what it doesn't (megavolt-0019)
+
+It builds on 199 as 199 stands: the store layout under `<configDir>/secrets/agents/<business>/<agent>/`, the
+lifecycle verbs and their `changes.jsonl` receipts, `useFor(session, service, fn)` with the D5 allowlist test,
+`assertClean` on every result, and the grant shape of `publish` (a list on the role entry, checked by the
+broker, plus a hard-wait action that isn't routed).
+
+This row's own changes:
+- A host kind in the closed kind set (vocabulary.mjs `SERVICES`, credentials.mjs, the broker's service check,
+  the CLI date flag, the remove regex), with a naming rule for one credential per host or per agent.
+- A per-kind value check. An OpenSSH private key fails today's `TOKEN` pattern.
+- Handing the key to ssh without the agent seeing it: an ssh-agent on a private socket, or a 0600 temp file
+  removed on every path, the way publish's one-shot helper works.
+- Pinned host keys per host, and no trust on first use.
+- The command boundary: what an agent may run under sudo, and how output returns without echoing the secret.
+  This is the main design work.
+- The executor: a ticket and a host op running in the bus child, the same split row 199 uses for publish
+  (Megavolt's deviation in 199's BUILD.md).
+
+## Steps
+
+1. DESIGN.md first, in `agents/gizmoduck/work/queue-ROW/`. It answers each item above, names the grant shape
+   (`roles.<agent>.hosts` and a `host.sudo` action, or a reasoned alternative), says who grants (Jason, through
+   a reviewed role change, unless REQ-CRED-3 says otherwise), and lists tests and mutants. Duckworth approves it
+   before code. Sage reads it too, because it gives agents sudo on hosts.
+2. Build on 199's candidate. Single test files run freely. Suites and mutant batches need Sage's slot.
+3. The live part is not this row. Putting a key in the store and granting a host is a separate window with
+   Jason or Mos, after landing.
+
+## Hosts
+
+The first targets are `localadmin` with NOPASSWD sudo on 10.1.1.53 and 10.1.1.54 (#423 step 1, applied by
+ops-01 at 20:05:47Z), and the servers agents already reach as localadmin (Q172). ops-01 owns the host side.
+Tests use scratch sshd fixtures on 127.0.0.1 or fakes, never a real host.
+
+## Boundaries
+
+- No change to `~/.mosaic-dev`, `~/.config/mosaic-dev`, slot files, the live units or `~/.mosaic`. No key is
+  read, copied or printed. No ssh to any real host from a test or a seat.
+- No widening of row 199's kinds or regex inside row 199. Both rows touch them, so this row rebases after 199
+  lands.
+
+## Gate
+
+Duckworth approves DESIGN.md, then the manifest. The bus, business and cli suites and every
+`scripts/test-*.sh` are green on Sage's gate, and the mutants are killed (one per refusal, plus one that leaks
+the key into the agent's output and one that skips the host key pin).
@@ -1,77 +1,66 @@
-# Brief: Melanie's hub instance on its own host (row 195, was 190b)
+# Brief: the Case 1 install on 10.1.1.53 (row 195)

-Sage, 2026-10-20. Rewritten for Mos's rulings mos-0998 and mos-1005 (Vikunja #418, #419). The first version
-put the hub under its own Linux user on dragon-lin. That form can't pass Duckworth's B7 there, because the
-factory uid's `sudo -n` succeeds on dragon-lin (Mos's recon, brain-redux
-`projects/mosaic-mvp/MELANIE-HOST-RECON.md`). Melanie's own server is ruled out too: it has 1.2 GiB RAM free
-with her two Hermes bots running, and co-tenancy would share her user and her passwordless sudo. The hub runs
-on a separate host. Which host is Jason's decision (#419): hardware outside the cluster, a cluster VM with
-factory PVE root removed, or a cluster VM with that residual accepted. This row is written so the host choice
-doesn't change it. Gitea #1693. On the 10-27 MVP path. Federation R8 (Gizmoduck's design r4, 04a6112be) needs
-this row or nothing.
+Sage, 2026-10-20, third version, for Darkwing's rewrite request and sage-1439. Gitea #1693.

-Owner Darkwing (Opus 5.5), reviewer Duckworth (author of B5 and B7), gate owner Sage. Chained on row 190
-(Q177): the hub runs under row 190's config canon. Design first. The first deliverable is
-`agents/darkwing/work/queue-190b/DESIGN.md`.
+Why it changed:
+- The first two versions put Melanie's hub on its own Linux user, then on its own host, Jason's choice under
+  #419.
+- Q181 settled the hosts: Case 1 (Jason's software factory) runs on 10.1.1.53 and Case 2 (Melanie's hub) on
+  10.1.1.54.
+- Q182 and Q183 made the hub's privilege checks a recorded acceptance. They report and don't refuse
+  (federation R8, mos-1055, mos-1063, mos-1066).
+- The Case 2 install on .54 is Gosalyn's C2-13 plus its window (#416, due by 2026-10-27). It is not this row.
+
+This row now installs Case 1 on .53. On the 10-27 MVP path (mos-0974, T1 item 1).
+
+Owner Darkwing (Opus 5.5), reviewer Duckworth, gate owner Sage. Chained on row 190's candidate (the config
+canon) and on C2-13's candidate (the install script), Q177. It reuses C2-13's `case2-install.sh`,
+`case2-precheck.sh` and `case2-unit.sh` by input, not by copy. A gap in them goes to Gosalyn as a C2-13
+change, or into this row's manifest as a named, reviewed change to those files. Design first:
+`agents/darkwing/work/queue-195/DESIGN.md`.

 ## Goal

-Melanie's hub instance (Case 2, C2-13) runs on its own host. No factory agent can read or write the hub's
-config, data root or secrets, reach its bus socket, or log in to the hub host. Her writing reaches the hub only
-through the existing git.mosaicstack.dev remotes, books repo only.
+Jason's software factory runs on 10.1.1.53 as `mosaic` under `/srv/mosaic`, in the same unit form as Case 2
+(design 9, Q181). It uses row 190's config canon and the model account the factory uses today (Q185,
+mos-1081 item 1). No new provider account.

-## Provision (blank until Jason answers #419)
+## Provision

-Who provisions the host and how is left open. Sizing from Mos (mos-0998): 4 vCPU, 8 GB RAM, 64 GB disk,
-internal network only. Each agent process measures 300 to 390 MB RSS on dragon-lin. The design takes the host
-as given: a fresh Linux host with a named admin path, reachable by the deploying seat while the row runs.
+- ops-01 runs the root steps over ssh as `localadmin`: `useradd mosaic`, `/srv/mosaic` and the unit through
+  `case2-unit.sh` from a root-owned checkout. #423 step 1 (localadmin with NOPASSWD sudo on .53 and .54) was
+  applied at 20:05:47Z (mos-1066, mos-1077), and nothing else in #423 gates this row.
+- #423 step 4 (jarvis sudo) waits until Case 1 is live on .53.
+- The host list comes from Q181. Agents may run read-only checks on .53 as `localadmin`.

 ## The design must state

-1. The deploy. Exactly what Darkwing installs on the hub host and how: the stack copy, node, the units, the
-   config dir and data root under row 190's canon (O1: `~/.config/mosaic-NAME`, and "`~` is the home of the OS
-   user that runs the instance"). Which commands run as which user on the hub host, and which need its root.
-2. Re-pin, rollback and backup on the hub host, and who runs them after the deploy key is gone.
-3. How the hub gets model access without a copy of jwoltje's `claude-session.env` or any factory credential.
-   If that needs the credentials row (T1 item 6), say so and name the interim. If it needs a new subscription
-   or a new provider account, flag it for Jason and don't pick one (mos-1008).
-4. The books repo path. Which git.mosaicstack.dev remote, which credential the hub holds for it, and that it
-   can't read or push any other repository.
-5. The admin path and the end state. The host ends with no key the factory uid can read. The design names the
-   admin path that remains (for example the hypervisor console, or a key kept off the factory uid) and who
-   holds it.
-6. The acceptance script, as code Duckworth can read. It takes Gizmoduck's list of infrastructure gate items
-   as its input (mos-1011), not a fixed set of checks. Each item names a path, its closed form and its
-   accepted form, and the script reports which form holds for each, or fails. The list covers at least:
-   - federation R8's separate-host form: the hub's bus socket, data root and config dir don't exist on the
-     factory host, the factory host mounts nothing of the hub's, and no factory agent holds a login or key
-     for the hub host
-   - B7: from the factory uid, `sudo -n`, `doas -n`, `su`, polkit, and `ssh -o BatchMode=yes` to the hub
-     host all fail
-   - the hypervisor and backup paths ops-01 measured (mos-1011: one PVE node the factory key has root on,
-     PBS on that node with unencrypted backups, a flat /16 LAN), each closed or accepted by Jason
-7. The identity provider and TLS front end (B8, mos-1008, mos-1011). Either the factory holds no credential
-   that can create users, change groups, issue tokens or impersonate in the issuer the hub trusts, or the hub
-   uses an issuer the factory can't administer. A brand, tenant or app inside the same Authentik does not
-   count as separate. The same holds for the TLS front end that serves the hub. The proof is a failed admin
-   call from every token the factory's root can read. No credential value is printed in that proof.
+1. The install as input values to C2-13's scripts: user, home, business file, roles, the human id, the
+   token slot path. Which commands run as `mosaic` through `sudo -u mosaic -H`, and which as root through
+   ops-01.
+2. Where Case 1 differs from Case 2: the factory roles in place of the library business, no library sync,
+   and any precheck item that doesn't apply, each with a reason.
+3. Model access through the existing factory account (Q185). Placing the credential on .53 is a step under
+   the Q173 secrets rule, done in the window. It is never copied by the script, and its value is never
+   printed.
+4. Re-pin, rollback and backup on .53, and who runs them.
+5. The acceptance checks, as code Duckworth can read. Each check names a path and gives it one of three
+   marks: closed, accepted under Q182 or Q183, or "not named in Q182 or Q183". An accepted path doesn't
+   fail the row. An unnamed one is reported to Mos, who takes it to Jason (the R8 N1 rule). The functional
+   checks fail the row when they fail: the unit runs as `mosaic`, the Console answers on its port on the
+   internal network only, and one tester message gets a reply.

 ## Boundaries

- Provisioning, hypervisor access and any infra or k3s change are Jason's (Q173 exclusions). Mos takes the
-  hypervisor residual (factory root on the PVE nodes, Q172) to Jason. It doesn't block this row.
- Melanie's server (`[email protected]`) is reference only, read only, under Jason's authorization in
-  mos-0995. Nothing on it changes, and her Hermes bots keep running.
- No tunnel, Traefik or other exposure outside the internal network. That waits for Jason, after Q175 SSO.
- No credential value is printed, logged or committed. Keys made for the deploy are removed at the end, and
-  the acceptance script proves it.
- The admin-call proof in point 7 and any call to the issuer or the TLS front end run only in a window Mos
-  approves, never as a test or an anonymous probe (Q175).
- Tests in the repository use scratch roots and stand-ins. The live deploy and the acceptance run on the hub
-  host are a window with a backup first (where there is state) and a STATE report after.
+- Infra and k3s changes, exposure outside the internal network, and spend stay Jason's (Q173 exclusions).
+- No change to dragon-lin's `~/.mosaic-dev`, `~/.config/mosaic-dev`, its live units or `~/.mosaic`.
+- No credential value is printed, logged or committed.
+- Tests use scratch roots and stand-ins. Nothing in a test reaches .53.
+- The run on .53 is a window with Jason's or Mos's go, a backup first where state exists, and a STATE report
+  after.

 ## Gate

 Duckworth approves DESIGN.md, then the manifest. Any repository change is green on Sage's gate (cli suite and
-every `scripts/test-*.sh`), with the design's mutants killed. The row is done when the acceptance script passes
-on the hub host from the factory uid, Duckworth reads its output, and Mos confirms.
+every `scripts/test-*.sh`), with the design's mutants killed. The row is done when the window's acceptance
+run passes on .53, Duckworth reads its output, and Mos confirms.
@@ -0,0 +1,70 @@
+# Row 193 build rows: 193a, 193b1, 193b2, 193c and 193d (#1691)
+
+Sage, 2026-10-20, for Mos's go mos-1034 item 4. Row 193's design is Morgana's
+`agents/morgana/work/queue-193/DESIGN.md` at e2d161e2e on `morgana/row193` (r5, sha256
+dd7fcb419ed8510e9d8d74b569183386d0942af8b68eecc0bbb5e182e677b523), approved by Duckworth (duckworth-0018).
+Section 8 lists the tests and mutants, and section 9 the split. The brief behind them is
+`docs/plans/2026-10-20_human-users.md`. Vikunja P19 #414/#415, Gitea #1691.
+
+Owner Morgana for every row, reviewer Duckworth, gate owner Sage. Each row chains on its parent's candidate
+(Q177) and rebases onto the parent's landing. Seats push only their own `<seat>/*` branches (mos-0981).
+Single test files run freely, and suites and mutant batches need Sage's slot.
+
+Boundaries for every row: no change to `~/.mosaic-dev`, `~/.config/mosaic-dev`, the live units, slot files, any
+live access.json or `~/.mosaic`. No request to the live Console, mosaic.woltje.com or auth.diversecanvas.com.
+No user thread goes live before 193b1's message filter has landed (mos-1021 B2, FED R8).
+
+The owner-visible records are fixed by Mos (mos-1023 item 2) and named in one user sentence, which FED R6
+reuses word for word: "The business owner sees your thread's agent's decisions, inbox entries, claims, tasks
+and project files, but not your messages."
+
+## Brief: 193a, the access level check widened to viewer
+
+Chained on FED R1. Started early on `morgana/row193a` (508ee4d61) against R1's interface as the FED brief
+names it, with Sage's go (sage-1373). R1's level check accepts `viewer` and still refuses any other new
+level. Tests in `packages/business/tests/` (section 8, Business), with the four mutants in Morgana's
+BUILD.md. FED R4 chains on this row.
+
+Duckworth's N1 on R1 (duckworth-0033, sage-1417): with viewer added, `covers` called with no level would let a
+viewer grant cover a collaborator ask. This row makes `level` required in `covers`, with a test and a mutant that
+makes it optional again. R3 and R4 call `covers` with a level.
+
+Gate: Duckworth approves the manifest. The business suite and every `scripts/test-*.sh` are green on Sage's
+gate, and the mutants are killed.
+
+## Brief: 193b1, viewer verbs, board refusals and the message filter
+
+Chained on FED R3, FED R4 and row 196's verifier. The bus gets the viewer verb list, per-grant level
+checks, board reads refused to users, and the section 5.7 `trail` and `replies` filter with `#readable`
+owner-only. No schema change. The governance pin test names each item in the user sentence above. Bus tests
+and mutants 1, 3, 6, 10, 11 and 12 from section 8.
+
+Gate: Duckworth approves the manifest. The bus suite and every `scripts/test-*.sh` are green on Sage's gate,
+and the mutants are killed.
+
+## Brief: 193b2, thread shares (schema 3j)
+
+Chained on 193b1. `thread_shares`, the share verbs, the share rules of `#readable` and `#threadRead`, and the
+section 5.5 share filters. Schema 3i to 3j. The table is append-only, and row 181's restore guard and
+`COUNTED` include it. Bus tests for shares and the migration, and mutants 2, 4, 7, 8 and 9 from section 8.
+Going live needs a `--migrate` window with Jason. Sage takes it to Mos when this row is near.
+
+Gate: Duckworth approves the manifest. The bus suite, the cli suite and every `scripts/test-*.sh` are green on
+Sage's gate, and the mutants are killed.
+
+## Brief: 193c, mosaic access user verbs and --level viewer
+
+Chained on FED R5. `mosaic access user add/remove` and `grant --level viewer`, only where R5 lacks them. They
+refuse tester and agent callers, write a receipt line and call `access.reload` (section 8, CLI). If R5
+already has all of them, this row records that and closes with no code.
+
+Gate: Duckworth approves the manifest. The cli suite and every `scripts/test-*.sh` are green on Sage's gate,
+and the mutants are killed.
+
+## Brief: 193d, the Console's shared list, share controls and viewer read-only
+
+Chained on FED R6, row 192 and 193b2 (for share controls). A viewer has no composer or share control, and
+with each UI check removed the bus still refuses (section 8, Webui).
+
+Gate: Duckworth approves the manifest. The webui suite and every `scripts/test-*.sh` are green on Sage's
+gate, and the mutants are killed.
@@ -24,11 +24,26 @@ on 7331 now (`ss -ltnp`, 2026-10-20T19:05:09Z), so retiring it costs the least.
   Update the docs that tell people to start it. The AGENTS.md text about the control-board reply convention
   is a separate matter. Change it only if it tells someone to start 7331.

+## Mos's call on the Console dependency (mos-1019)
+
+The inventory (004f133bd) found that the Console proxies `/api/board`, `/api/seen`, `/api/reply` and the
+conversation routes to `DEFAULT_BOARD` on 7331 (`packages/webui/src/serve.mjs:12`), so the board view returns
+502 today. Mos took Sage's recommendation: retire the 7331 listener and its README start commands, and have
+the Console call the board's read code in-process, behind the Console's own auth (Q175 SSO on 7332).
+`/api/reply` stays only under `--send`. The DESIGN.md for that change comes before code, and Webby approves
+it.
+
 ## Acceptance

 Nothing in the stack can start a writer on 7331. A test proves it: the entry point refuses (or is gone), no
 script or unit starts it, and a grep check finds no starter. Each change gets a mutant that brings the writer
-back and the test kills it.
+back and the test kills it. Mos added three items (mos-1019):
+
+- The board view answers from the Console with nothing listening on 7331.
+- Every board route sits behind the Console's auth.
+- A test proves `/api/reply` refuses without `--send`.
+
+Test fixtures that bind port 0 may stay if they only test the code in-process.

 ## Boundaries

@@ -38,5 +53,5 @@ back and the test kills it.

 ## Gate

-Webby approves INVENTORY.md, then the manifest. The control-board and webui package suites, the cli suite and
+Webby approves INVENTORY.md, then DESIGN.md, then the manifest. The control-board and webui package suites, the cli suite and
 every `scripts/test-*.sh` are green on Sage's gate, and the mutants are killed.
@@ -0,0 +1,39 @@
+# Brief: stack-release.sh activates a Console with --sso (Q175 phase 2 prerequisite)
+
+Sage, 2026-10-20, for Launchpad's finding F3 on row 192 (launchpad-0001) and Q175 (#412). Gitea #1698. Owner
+Launchpad, reviewer Webby, gate owner Sage. Chained on row 192's candidate (Q177): it lands after row 192 and
+before the phase 2 window. Base: row 192's candidate.
+
+## Why
+
+The phase 2 window re-pins the Console to the phase 1 commit with `--sso --send --tester-port 7333`
+(`agents/sage/work/q175-sso/DESIGN.md`, section 5). `scripts/stack-release.sh` doesn't know `--sso` today.
+Its `proof_checks` (`:751`) requires `--public-host`, `--auth-header` and `--allow-user` whenever a proof pair is
+carried, and the pointer's Console flags still hold the forward-auth pair (`--auth-header X-authentik-username
+--allow-user jason.woltje`) that `--sso` refuses to start with. So the window can't run through the script, and
+a hand-edited pointer is not an option.
+
+## What the row does
+
+1. `activate ID BUSINESS --sso` writes Console flags with `--sso` and without `--auth-header`, `--allow-user`
+   and any proof pair, and `--plan` names each flag it drops and carries, in the style of row 189's `send:`
+   line. The design names the full flag set the phase 2 Console starts with and checks it against row 192's
+   refusals.
+2. Before anything stops, the script refuses a target copy whose Console doesn't support `--sso`, and refuses
+   when the config's `console` key or its slot file fails the checks row 192's `--sso` start runs. It reads
+   neither value and only uses the same stat and shape checks.
+3. Rollback from an `--sso` pointer to a pre-phase-1 copy follows the design's phase 2 rollback order (remove
+   the `console` key first). The script refuses a rollback that would start a Console on a config it can't
+   read, and says which step comes first.
+4. `docs/TOOLS.md` gets the flag.
+
+## Boundaries
+
+- No change to the live pointer, units, `~/.mosaic-dev` or `~/.config/mosaic-dev`. Tests use scratch roots
+  and seeded pointers, as rows 187 and 189 do.
+- No request to the live Console, mosaic.woltje.com or auth.diversecanvas.com.
+
+## Gate
+
+Webby approves the manifest. The cli suite and every `scripts/test-*.sh` are green on Sage's gate, and the
+mutants are killed (one per refusal, and one that keeps `--auth-header` in the written flags).
@@ -33,7 +33,7 @@ Gaps found while working go to `docs/plans/DEFERRED.md`, not here.

 <!-- mosaic-queue:begin -->

-Generated from `docs/plans/queue.json` revision 2247 by `queue render`. Do not edit between the markers; change the queue with `scripts/mosaic queue`.
+Generated from `docs/plans/queue.json` revision 2361 by `queue render`. Do not edit between the markers; change the queue with `scripts/mosaic queue`.

 | # | Piece | Owner | Issues | State | After | Gate | Brief | Note |
 |---|---|---|---|---|---|---|---|---|
@@ -225,9 +225,29 @@ Generated from `docs/plans/queue.json` revision 2247 by `queue render`. Do not e
 | 186 | stack-release --plan: the backup line says what the run will do (P19 404, row 185 N1/N2) | darkwing; reviewers filbert | #1684 | done | — | Filbert approves the manifest; cli suite and every scripts/test-*.sh green on Sage's gate; the three brief mutants killed (sage) | `docs/plans/2026-10-20_plan-backup-line.md` § Brief: the activate plan's backup line says what the run will do | Landed 269134d8d (author Darkwing) on 3c5da3a91. Patch-id c97b9f6e25cd matches the r1 candidate (manifest 449e9121, Filbert approve 29419). Sage gate on b367f5730+patch 09:00:20Z-09:08:59Z: node 2681/0, scripts 422/0, queue 156, network removed; 3c5da3a91 adds only a SESSIONS line. Not live: the stack runs copy 490e2771d3d0. Follow-ups on P19 404: Filbert M6 gap, store-unclean reading. |
 | 187 | stack-release activate carries the row 178 proof pair (mos-0928 Part B A0) | darkwing; reviewers filbert | #1685 | done | 186 done | Filbert approves the manifest; cli suite and every scripts/test-*.sh green on Sage's gate; the brief mutants killed (sage) | `docs/plans/2026-10-20_activate-proof-pair.md` § Brief: activate carries the row 178 proof pair | Landed 9a71e4e80 (author Darkwing) on d17328a55; patch-id 6b57c47bc661 matches candidate 52a5ecc1d143 and Filbert's r1 reading. Sage gate passed 10:21:55Z: cli 446/446 and every package and scripts/test-*.sh green. Filbert approve 29424, rev 2204; follow-ups N1-N4 filed on P19. |
 | 188 | stack-release tests: a carried proof pair and a proof file inside the repository (P19 409, 410; gates Part B) | darkwing; reviewers filbert | #1686 | done | 187 settled | Filbert approves the manifest; cli suite and every scripts/test-*.sh green on Sage's gate; the brief mutants killed (sage) | `docs/plans/2026-10-20_proof-test-gaps.md` § Brief: tests for the two proof-file paths row 187 left open | Landed 8fc0ee216 (author Darkwing) on 23a609c5c; patch-id c9a56b167c07 matches candidate 86aa549bad75 and Filbert's r1 reading; stack-release.sh blob 2586a2a37cd2 unchanged. Sage gate passed 10:58Z: cli 453/453 and every package and scripts/test-*.sh green. Filbert approve 29433, rev 2212; N1 (REPO logical path) to P19 after Part B (mos-0959). |
-| 189 | stack-release activate --no-send drops the Console's --send and keeps the pointer in step (Q175 interim, mos-0972, P19 413) | sage; reviewers dewey | #1687 | in-review, round 1, request posted | 163 done | Dewey approves the manifest; cli suite and every scripts/test-*.sh green on Sage's gate; the brief mutants killed (sage) | `docs/plans/2026-10-20_activate-no-send.md` § Brief: activate --no-send drops the Console's --send | — |
-| 190 | several Mosaic Stack instances on one host: per-instance config, data root, units and ports (MVP T1.1, mos-0974, Vikunja #414) | darkwing; reviewers filbert | #1688 | in-progress | — | Filbert approves DESIGN.md then the manifest; cli suite and every scripts/test-*.sh green on Sage's gate; the design mutants killed (sage) | `docs/plans/2026-10-20_multi-instance.md` § Brief: several Mosaic Stack instances on one host | — |
+| 189 | stack-release activate --no-send drops the Console's --send and keeps the pointer in step (Q175 interim, mos-0972, P19 413) | sage; reviewers dewey | #1687 | done | 163 done | Dewey approves the manifest; cli suite and every scripts/test-*.sh green on Sage's gate; the brief mutants killed (sage) | `docs/plans/2026-10-20_activate-no-send.md` § Brief: activate --no-send drops the Console's --send | Landed ace27dc5e on refactor (cherry-pick of candidate d6116771f onto a4a42dbac). Gate GATE_PASSED on 0c177e9ef (base 0217b71c8), 2026-10-20T19:09:37Z-19:20:36Z, 25 suites rc=0. patch-id ce89378718f6 for both 0c177e9ef and ace27dc5e; range-diff differs only in the message. Landed manifest hashes to 67af69bd (Dewey approve 29485). Base drift 0217b71c8..a4a42dbac: 7 doc/README files, none on manifest paths, no test reads them. Brief re-pinned to blob 29a9e6d2d. |
+| 190 | several Mosaic Stack instances on one host: per-instance config, data root, units and ports (MVP T1.1, mos-0974, Vikunja #414) | darkwing; reviewers filbert | #1688 | in-review, round 1, request posted | — | Filbert approves DESIGN.md then the manifest; cli suite and every scripts/test-*.sh green on Sage's gate; the design mutants killed (sage) | `docs/plans/2026-10-20_multi-instance.md` § Brief: several Mosaic Stack instances on one host | — |
 | 191 | one kill switch for the bus, every run, Discord and new launches, from the CLI and the Console (MVP T1.4, mos-0974, Vikunja #414) | rocko; reviewers dewey | #1689 | in-progress | — | Dewey approves DESIGN.md then the manifest; cli, bus, discord and webui suites and every scripts/test-*.sh green on Sage's gate; the mutants killed (sage) | `docs/plans/2026-10-20_kill-switch.md` § Brief: one kill switch for the bus, every run, Discord and new launches | — |
+| 192 | Q175 phase 1: the Console verifies SSO itself (--sso), OIDC RP with oauth4webapi 3.8.8, no live change (MVP T1.2, #412) | launchpad; reviewers webby | #1690 | in-review, round 2, request posted | — | Webby approves the manifest; webui and cli suites, scripts/test-config.sh and every scripts/test-*.sh green on Sage's gate; design section 9 mutants killed (sage) | `docs/plans/2026-10-20_sso-phase1.md` § Brief: Q175 phase 1, the Console verifies SSO itself (--sso) | — |
+| 193 | many humans per business, human roles, private and shared threads, one access.json store (MVP T1.3, Vikunja #414/#415) | morgana; reviewers duckworth | #1691 | in-progress | — | Duckworth approves DESIGN.md then the manifest; bus, business, cli and webui suites and every scripts/test-*.sh green on Sage's gate; the mutants killed (sage) | `docs/plans/2026-10-20_human-users.md` § Brief: many humans per business, human roles, private and shared threads | — |
+| 194 | agent lifecycle from the Console and the CLI (create, launch, terminate, regenerate, delete) with a per-agent hire/fire veto (MVP T1.5, Vikunja #414/#415) | honker; reviewers webby | #1692 | in-progress | — | Webby approves DESIGN.md then the manifest; bus, cli, business and webui suites and every scripts/test-*.sh green on Sage's gate; the mutants killed (sage) | `docs/plans/2026-10-20_agent-lifecycle.md` § Brief: agent lifecycle from the Console and the CLI, with a per-agent hire/fire veto | — |
+| 195 | row 195: the Case 1 install on 10.1.1.53 as mosaic under /srv/mosaic, reusing C2-13's scripts by input under row 190's canon (Q181, Q182/Q183, Q185; ops-01 root steps under #423 step 1) | darkwing; reviewers duckworth | #1693 | briefed | 190 done | Duckworth approves DESIGN.md then the manifest; cli suite and every scripts/test-*.sh green on Sage's gate; the mutants killed (sage) | `docs/plans/2026-10-20_hub-own-uid.md` § Brief: the Case 1 install on 10.1.1.53 (row 195) | sage-1439: rewritten to Case 1 on .53 (f24f2cd40). Chains on C2-13's candidate too once C2-13 is queued. Darkwing starts DESIGN.md after row 190's mutants. |
+| 196 | the human boundary across uids and humans: Console, tester listener, broker.sock and the path-bound human proof (P19 333, before federation R3, mos-0989) | gander; reviewers duckworth | #1694 | in-progress | — | Duckworth approves DESIGN.md then the manifest; bus, webui and cli suites and every scripts/test-*.sh green on Sage's gate; the mutants killed (sage) | `docs/plans/2026-10-20_human-boundary.md` § Brief: the human boundary across uids and humans (P19 333) | — |
+| 197 | a second gate lane: two full gates at once on dragon-lin, design first (mos-0977 item 6) | herb; reviewers webby | #1695 | in-progress | — | Webby approves DESIGN.md then the manifest; cli suite and every scripts/test-*.sh green on Sage's gate, singly and in the two-lane proof (sage) | `docs/plans/2026-10-20_second-gate-lane.md` § Brief: a second gate lane, two full gates at once on dragon-lin | Order with row 198 (Sage, mos-1040 N1): 197 lands first. After B1 the shared tests are packages/webui/tests/serve.test.mjs:100 and preview.test.mjs:208. Row 198 rebases onto 197's landing before its manifest review. |
+| 198 | retire the control board writer on 7331 (unauthenticated loopback writer, Q175; mos-1008) | bushroot; reviewers webby | #1696 | in-progress | 192 done, 197 done | Webby approves INVENTORY.md then the manifest; control-board, webui and cli suites and every scripts/test-*.sh green on Sage's gate; the mutants killed (sage) | `docs/plans/2026-10-20_retire-control-board.md` § Brief: retire the control board writer on 7331 | Order with row 197 (Sage, mos-1040 N1): 197 lands first. Row 198 rebases onto 197's landing before its manifest review; shared tests are packages/webui/tests/serve.test.mjs:100 and preview.test.mjs:208. |
+| 199 | MVP T1 item 6: a credential store per agent, own git identity, pushes to a remote (G11, G13; mos-0974) | megavolt; reviewers duckworth | #1697 | in-progress | — | Duckworth approves DESIGN.md; Mos rules on the authority model; Duckworth approves the manifest; bus, business, cli and tasks suites and every scripts/test-*.sh green on Sage's gate; the mutants killed (sage) | `docs/plans/2026-10-20_agent-credentials.md` § Brief: a credential store per agent, own git identity, pushes to a remote | — |
+| 200 | stack-release.sh activate --sso for the Q175 phase 2 window (row 192 F3; chained on 192) | launchpad; reviewers webby | #1698 | in-review, round 2, request posted | — | Webby approves the manifest; cli suite and every scripts/test-*.sh green on Sage's gate; the mutants killed (sage) | `docs/plans/2026-10-20_stack-release-sso.md` § Brief: stack-release.sh activates a Console with --sso (Q175 phase 2 prerequisite) | — |
+| 201 | FED R1: access.json loader and validator, and covers (#414) | gizmoduck; reviewers duckworth | #1699 | in-review, round 1, request posted | — | Duckworth approves the manifest; business suite and every scripts/test-*.sh green on Sage's gate; the mutants killed (sage) | `docs/plans/2026-10-20_federation-r1-r2-r5.md` § Brief: FED R1, the access.json loader and validator | — |
+| 202 | FED R5: mosaic access list, grant and revoke (#414) | quackerjack; reviewers duckworth | #1700 | in-review, round 1, request posted | — | Duckworth approves the manifest; cli suite and every scripts/test-*.sh green on Sage's gate; the mutants killed (sage) | `docs/plans/2026-10-20_federation-r1-r2-r5.md` § Brief: FED R5, mosaic access list, grant and revoke | Chained on row 201's candidate (Q177), not its done: claimable now, lands after 201 and rebases onto its landing (Sage) |
+| 203 | FED R2: the federation key in the system config (#414) | quackerjack; reviewers webby | #1701 | briefed | — | Webby approves the manifest; cli suite and every scripts/test-*.sh green on Sage's gate; the mutants killed (sage) | `docs/plans/2026-10-20_federation-r1-r2-r5.md` § Brief: FED R2, the federation key in the system config | Chained on row 192's candidate (Q177): starts on 192's candidate, lands after 192 (Sage) |
+| 204 | 193a: access level check widened to viewer (#1691) | morgana; reviewers duckworth | #1702 | in-review, round 1, request posted | — | Duckworth approves the manifest; business suite and every scripts/test-*.sh green on Sage's gate; the mutants killed (sage) | `docs/plans/2026-10-20_human-users-build.md` § Brief: 193a, the access level check widened to viewer | Chained on row 201's candidate (Q177), not its done: claimable now, lands after 201 and rebases onto its landing (Sage) |
+| 205 | 193b1: viewer verbs, board refusals and the message filter (#1691; also after FED R3 and R4 when filed) | morgana; reviewers duckworth | #1703 | queued | 196 done | Duckworth approves the manifest; bus suite and every scripts/test-*.sh green on Sage's gate; the mutants killed (sage) | `docs/plans/2026-10-20_human-users-build.md` § Brief: 193b1, viewer verbs, board refusals and the message filter | — |
+| 206 | 193b2: thread shares, schema 3j (#1691; live needs a --migrate window with Jason) | morgana; reviewers duckworth | #1704 | queued | 205 done | Duckworth approves the manifest; bus suite, cli suite and every scripts/test-*.sh green on Sage's gate; the mutants killed (sage) | `docs/plans/2026-10-20_human-users-build.md` § Brief: 193b2, thread shares (schema 3j) | — |
+| 207 | 193c: mosaic access user verbs and --level viewer (#1691) | morgana; reviewers duckworth | #1705 | queued | 202 done | Duckworth approves the manifest; cli suite and every scripts/test-*.sh green on Sage's gate; the mutants killed (sage) | `docs/plans/2026-10-20_human-users-build.md` § Brief: 193c, mosaic access user verbs and --level viewer | — |
+| 208 | 193d: Console shared list, share controls and viewer read-only (#1691; also after FED R6 when filed) | morgana; reviewers duckworth | #1706 | queued | 192 done, 206 done | Duckworth approves the manifest; webui suite and every scripts/test-*.sh green on Sage's gate; the mutants killed (sage) | `docs/plans/2026-10-20_human-users-build.md` § Brief: 193d, the Console's shared list, share controls and viewer read-only | — |
+| 209 | FED R8: the hub window on 10.1.1.54, a recorded acceptance (#414, r4.11 b93f098f0; live window run by Jason and Mos, after the Case 2 install #416, Bean and Chet live and both Hermes gateways stopped) | sage; reviewers duckworth | — | queued | — | Every entry check's output is in the R8 record with who ran it; Jason signs in to the hub and sends one message, Melanie revokes, his next request is refused; Duckworth checks the record (sage) | `docs/plans/2026-10-20_federation-r1-r2-r5.md` § Brief: FED R8, the hub window on 10.1.1.54 | Stays queued until its entry gates near: Case 2 install on .54 (#416, by 2026-10-27), Bean and Chet live, both Hermes gateways on .54 stopped, R7, #412 phase 2, #419 answer. Filed per mos-1073 after duckworth-0034 (Sage) |
+| 210 | Agent host access with sudo through the credential store: grant per agent and host, the stack does ssh and sudo, the agent never sees the key (#1707, Vikunja #424, Q183/Q184, due 10-27; chained on row 199's candidate) | gizmoduck; reviewers duckworth | #1707 | in-progress | — | Duckworth approves DESIGN.md, then the manifest; bus, business, cli suites and every scripts/test-*.sh green on Sage's gate; the mutants killed (sage) | `docs/plans/2026-10-20_host-credentials.md` § Brief: agent host access with sudo through the credential store (#424) | Design runs before 199 lands (Q177 chain on 199's candidate). after cleared so Gizmoduck can claim; lands only after 199 and rebases onto it. |
+| 211 | Force-push guard: scripts/git-hooks/pre-push refuses non-fast-forward and delete pushes from every worktree, and scripts/slot-busy.sh exits 1 on BUSY (#1709, Vikunja #426, mos-1078/1083) | rocko; reviewers dewey | #1709 | briefed | — | Dewey approves the manifest; the new or changed scripts/test-*.sh and every other scripts/test-*.sh green on Sage's gate; the mutants killed; hook installed in the canonical checkout with a scripted refused force-push (sage) | `docs/plans/2026-10-20_force-push-guard.md` § Brief: a pre-push hook that refuses force-pushes, and a busy check that fails on BUSY (#426) | — |

 <!-- mosaic-queue:end -->

@@ -9,7 +9,8 @@
      "version": "0.0.3",
      "license": "UNLICENSED",
      "dependencies": {
-        "@earendil-works/pi-coding-agent": "0.85.1"
+        "@earendil-works/pi-coding-agent": "0.85.1",
+        "oauth4webapi": "3.8.8"
      }
    },
    "node_modules/@anthropic-ai/sdk": {
@@ -1933,6 +1934,15 @@
        "url": "https://opencollective.com/node-fetch"
      }
    },
+    "node_modules/oauth4webapi": {
+      "version": "3.8.8",
+      "resolved": "https://registry.npmjs.org/oauth4webapi/-/oauth4webapi-3.8.8.tgz",
+      "integrity": "sha512-8N28E+a/oxfXWBgOMt+ZP/JUf/XR+IFbvkAEPP3gznXOMv9BpAAwiIj0TFNz3tGTPc0ZQ8zmWBNgN1nAys0gng==",
+      "license": "MIT",
+      "funding": {
+        "url": "https://github.com/sponsors/panva"
+      }
+    },
    "node_modules/openai": {
      "version": "6.40.0",
      "resolved": "https://registry.npmjs.org/openai/-/openai-6.40.0.tgz",
@@ -5,6 +5,7 @@
  "description": "Minimal Mosaic Stack container proof of concept: one Pi agent, four local contract files, one real model request returning MOSAIC_HELLO_OK.",
  "license": "UNLICENSED",
  "dependencies": {
-    "@earendil-works/pi-coding-agent": "0.85.1"
+    "@earendil-works/pi-coding-agent": "0.85.1",
+    "oauth4webapi": "3.8.8"
  }
 }
@@ -717,6 +717,19 @@ without it, so Pi sessions still launch and a Claude Code launch refuses
 (or this line and this paragraph), then restart the unit; a running host
 keeps the environment it started with.

+A named stack instance (row 190) takes `--instance NAME` with any verb, in
+any position. The unit is then `[email protected]`, it sets
+`Environment=MOSAIC_CONFIG=` to `~/.config/mosaic-NAME/config.json`, its
+Description ends in ` [NAME]`, and its `EnvironmentFile=` is
+`secrets/claude-session.env` in that config directory, not mosaic-dev's.
+Install's busy and drop-in checks cover only `mosaic-bus-NAME@*` units and
+their `.d` directories, plus the prefix directories systemd applies to them:
+`mosaic-bus-.service.d`, `mosaic-.service.d` and `service.d`. A data root
+that another instance claims, or a named root with no `instance.json`, exits
+3 before anything is read. Without the flag the unit renders byte for byte
+as before. Selection, names and refusals are in
+[TOOLS.md, Stack instances](../../docs/TOOLS.md#stack-instances---instance-name-row-190).
+
 The unit has no `network-online.target` ordering, since a user unit cannot
 order on that system target. The notifier needs no network at start: a
 send that fails is journaled and retried.
@@ -13,6 +13,7 @@ StartLimitBurst=5
 Type=simple
 WorkingDirectory=@REPO@
 Environment=PATH=@PATH@
+@CONFIG_ENV@
 # The Claude Code binary that managed sessions and the manifest's
 # claudeVersion run, pinned at install (`--claude PATH`, default
 # `command -v claude`). Without it they run `claude` from PATH above.
@@ -21,7 +22,7 @@ Environment=PATH=@PATH@
 # operator writes: CLAUDE_CODE_OAUTH_TOKEN, ANTHROPIC_API_KEY, or a proxy's
 # ANTHROPIC_AUTH_TOKEN with ANTHROPIC_BASE_URL. The `-` lets the unit start
 # without it, and a Claude Code launch then refuses.
-EnvironmentFile=-%h/.config/mosaic-dev/secrets/claude-session.env
+EnvironmentFile=-@SESSION_ENV@
 # The host reads the system config and the business file, boots the broker
 # (packages/bus/src/process.mjs) and starts the notifier. Config problems and
 # refusals exit 3, usage 4, invalid input 2: none of those is retried. A
@@ -837,7 +837,11 @@ test("bus start --no-launch says launches are disabled in its host-up line and s
 test("bus-service.sh renders the unit and installs it into a given directory", (t) => {
  const dir = tmp(t);
  const script = join(REPO, "scripts", "bus-service.sh");
-  const render = spawnSync(script, ["render"], { encoding: "utf8" });
+  // Row 190: the script selects an instance from the system config first; a
+  // scratch path keeps it off ~/.config/mosaic-dev. A missing config selects
+  // the default names, as before.
+  const cfgEnv = { ...process.env, MOSAIC_CONFIG: join(dir, "absent", "config.json") };
+  const render = spawnSync(script, ["render"], { encoding: "utf8", env: cfgEnv });
  assert.equal(render.status, 0, render.stderr);
  assert.match(render.stdout, new RegExp(`ExecStart=${REPO.replace(/[.*+?^${}()|[\]\\]/g, "\\$&")}/scripts/mosaic bus start %i`));
  assert.match(render.stdout, /RestartPreventExitStatus=2 3 4/);
@@ -855,7 +859,7 @@ test("bus-service.sh renders the unit and installs it into a given directory", (
  const fakeBin=join(dir,"bin");mkdirSync(fakeBin);
  writeFileSync(join(fakeBin,"systemctl"),"#!/bin/sh\ncase \"$*\" in *list-units*) exit 0;; *)exit 99;; esac\n");chmodSync(join(fakeBin,"systemctl"),0o755);
  writeFileSync(join(fakeBin,"systemd-analyze"),`#!/bin/sh\nprintf '%s\\n' '${dir}/unit-search'\n`);chmodSync(join(fakeBin,"systemd-analyze"),0o755);
-  const unitEnv={...process.env,PATH:`${fakeBin}:${process.env.PATH}`};
+  const unitEnv={...cfgEnv,PATH:`${fakeBin}:${process.env.PATH}`};
  const first = spawnSync(script, ["install", "--dir", dir, "--no-reload"], { encoding: "utf8",env:unitEnv });
  assert.equal(first.status, 0, first.stderr);
  assert.match(first.stdout, /written: /);
@@ -863,7 +867,7 @@ test("bus-service.sh renders the unit and installs it into a given directory", (
  assert.equal(readFileSync(join(dir, "[email protected]"), "utf8"), render.stdout);
  assert.match(spawnSync(script, ["install", "--dir", dir, "--no-reload"], { encoding: "utf8",env:unitEnv }).stdout, /unchanged: /);
  assert.match(spawnSync(script, ["uninstall", "--dir", dir, "--no-reload"], { encoding: "utf8",env:unitEnv }).stdout, /removed: /);
-  assert.equal(spawnSync(script, ["bogus"], { encoding: "utf8" }).status, 4);
+  assert.equal(spawnSync(script, ["bogus"], { encoding: "utf8", env: cfgEnv }).status, 4);
 });

 // Row 68: the unit pins the Claude Code binary as MOSAIC_CLAUDE_BIN, from
@@ -882,7 +886,8 @@ test("bus-service.sh pins the claude binary, refuses one the unit can't carry, a
  const onPath = stand(join(dir, "bin", "claude"));
  const named = stand(join(dir, "claude-named"));
  symlinkSync(named, join(dir, "claude-link"));
-  const env = { ...process.env, PATH: `${join(dir, "bin")}:${dirname(process.execPath)}:/usr/bin:/bin` };
+  // Row 190: a scratch MOSAIC_CONFIG keeps the instance selection off ~/.config/mosaic-dev.
+  const env = { ...process.env, MOSAIC_CONFIG: join(dir, "absent", "config.json"), PATH: `${join(dir, "bin")}:${dirname(process.execPath)}:/usr/bin:/bin` };
  const run = (args, e = env) => spawnSync(script, args, { encoding: "utf8", env: e });
  const pinned = (out) => out.match(/^Environment=MOSAIC_CLAUDE_BIN=(.*)$/m)?.[1];

@@ -66,6 +66,23 @@ test('wrapper preserves Q81 lease and marker, rejects foreign/symlink; check use
 assert.notEqual(s.run('stack-copy.sh',['wrapper',s.id,'--copies',s.copies,'--bin',s.bin]).status,0);assert.equal(readFileSync(wrapper,'utf8'),foreign);
 const backing=join(s.bin,'backing');writeFileSync(backing,`#!/usr/bin/env bash\n${marker}\n${lease}\nexec \"/old/scripts/mosaic\" \"$@\"\n`);unlinkSync(wrapper);symlinkSync(backing,wrapper);assert.notEqual(s.run('stack-copy.sh',['wrapper',s.id,'--copies',s.copies,'--bin',s.bin]).status,0);
 });
+test('row 190 N6: check --instance passes only when the wrapper exports the instance\'s MOSAIC_CONFIG',t=>{
+ const s=setup(t);assert.equal(s.run('stack-copy.sh',['copy',s.id,'--copies',s.copies]).status,0);
+ const boot=s.run('bootstrap.sh',['--instance','alpha']);assert.equal(boot.status,0,boot.stderr);
+ const copy=join(s.copies,s.id),wrapper=join(s.bin,'mosaic-alpha'),cfg=join(s.root,'.config','mosaic-alpha','config.json');
+ const w=s.run('stack-copy.sh',['wrapper',s.id,'--instance','alpha','--copies',s.copies,'--bin',s.bin]);assert.equal(w.status,0,w.stderr);
+ s.fake(`echo 'LoadState=loaded';echo 'WorkingDirectory=${copy}';case "$*" in *mosaic-bus-alpha@demo*) echo 'ExecStart={ path=${copy}/scripts/mosaic ; argv[]=${copy}/scripts/mosaic bus start demo ; }';; *mosaic-webui-alpha*) echo 'ExecStart={ path=/usr/bin/node ; argv[]=/usr/bin/node ${copy}/packages/webui/src/cli.mjs serve ; }';; *) exit 1;; esac\n`);
+ const check=()=>s.run('stack-copy.sh',['check','--instance','alpha','--copies',s.copies,'--bin',s.bin,'--business','demo']);
+ const good=readFileSync(wrapper,'utf8');assert.equal(good.split('\n')[3],`export MOSAIC_CONFIG='${cfg}'`);
+ let r=check();assert.equal(r.status,0,r.stdout+r.stderr);assert.equal(r.stdout,`bus: ${copy}\nConsole: ${copy}\nCLI: ${copy}\n`);
+ for(const [label,text] of [
+  ['another config',good.replace(`export MOSAIC_CONFIG='${cfg}'`,`export MOSAIC_CONFIG='${join(s.root,'.config','mosaic-beta','config.json')}'`)],
+  ['no config line',good.replace(`export MOSAIC_CONFIG='${cfg}'\n`,'')],
+ ]){
+  writeFileSync(wrapper,text);r=check();
+  assert.equal(r.status,1,label);assert.equal(r.stdout,`bus: ${copy}\nConsole: ${copy}\nCLI: ${copy} (MOSAIC_CONFIG mismatch)\n`,label);
+ }
+});
 test('bus unit copy/pm pins, install refuses all busy states and failed reads, drop-in refusal',t=>{
 const s=setup(t);assert.equal(s.run('stack-copy.sh',['copy',s.id,'--copies',s.copies]).status,0);
 const args=['--copy',s.id,'--copies',s.copies,'--pm'];
@@ -0,0 +1,469 @@
+// Row 190 (#1688): several stack instances on one host. The config and bootstrap cases (T-I1, T-I2,
+// the config part of T-I7), two real bus hosts side by side (T-I5) and the guard (T-I10). Design and
+// T table: agents/darkwing/work/queue-190/DESIGN.md D7. The unit, port and release cases are T56 in
+// stack-release.test.mjs. HOME is a scratch directory in every test, so ~/.config/mosaic-* and
+// ~/.mosaic-* resolve inside it; nothing here reads or writes ~/.mosaic-dev or ~/.config/mosaic-dev.
+import { test } from "node:test";
+import assert from "node:assert/strict";
+import { spawn, spawnSync } from "node:child_process";
+import { once } from "node:events";
+import { chmodSync, cpSync, existsSync, lstatSync, mkdirSync, readdirSync, readFileSync, rmSync, statSync, symlinkSync, writeFileSync } from "node:fs";
+import { createHash } from "node:crypto";
+import { join, relative } from "node:path";
+import { fileURLToPath } from "node:url";
+import { LiveSessionGuard } from "../../conversation/src/guard.mjs";
+import { businessDoc, rolesCopy, writeJson } from "../../business/tests/helpers.mjs";
+import { REPO_SKILLS } from "../../harness/tests/helpers.mjs";
+import { humanEnv, notifyConfig, tmp } from "./helpers.mjs";
+
+const SCRIPTS = fileURLToPath(new URL("../../../scripts/", import.meta.url));
+const CONFIG = join(SCRIPTS, "mosaic-config.mjs");
+const BOOTSTRAP = join(SCRIPTS, "bootstrap.sh");
+const BUS_SERVICE = join(SCRIPTS, "bus-service.sh");
+const WEBUI_SERVICE = join(SCRIPTS, "webui-service.sh");
+const STACK_COPY = join(SCRIPTS, "stack-copy.sh");
+const MOSAIC = join(SCRIPTS, "mosaic");
+
+// The environment for a scratch home: no MOSAIC_CONFIG unless a test sets one.
+function homeEnv(home, extra = {}) {
+  const env = humanEnv({ HOME: home, ...extra });
+  if (!("MOSAIC_CONFIG" in extra)) delete env.MOSAIC_CONFIG;
+  delete env.XDG_CONFIG_HOME;
+  return env;
+}
+
+function run(cmd, args, env) {
+  const r = spawnSync(cmd, args, { env, encoding: "utf8", timeout: 30000 });
+  return { code: r.status, out: r.stdout, err: r.stderr };
+}
+
+const bootstrap = (home, ...args) => run(BOOTSTRAP, args, homeEnv(home));
+const config = (home, extra, ...args) => run(process.execPath, [CONFIG, ...args], homeEnv(home, extra));
+const cfgOf = (home, name) => join(home, ".config", `mosaic-${name}`, "config.json");
+
+// The instance op's exports as an object.
+function exportsOf(out) {
+  return Object.fromEntries(out.trim().split("\n").map((line) => {
+    const m = line.match(/^(\w+)='(.*)'$/);
+    assert.ok(m, `not a shell-safe export: ${line}`);
+    return [m[1], m[2]];
+  }));
+}
+
+// Every entry under `dir`: relative path, type, mode, size, mtime and content hash.
+function snapshot(dir) {
+  const out = {};
+  const walk = (d) => {
+    for (const name of readdirSync(d).sort()) {
+      const p = join(d, name);
+      const s = lstatSync(p);
+      const key = relative(dir, p);
+      if (s.isDirectory()) {
+        out[key] = { dir: true, mode: s.mode, mtime: s.mtimeMs };
+        walk(p);
+      } else {
+        out[key] = { mode: s.mode, size: s.size, mtime: s.mtimeMs, sha: createHash("sha256").update(readFileSync(p)).digest("hex") };
+      }
+    }
+  };
+  if (existsSync(dir)) walk(dir);
+  return out;
+}
+
+const mode = (p) => statSync(p).mode & 0o777;
+
+test("T-I1 bootstrap --instance creates each instance's config, root and marker once, and refuses what it must not claim", async (t) => {
+  await t.test("alpha and beta get a 0700 config dir, a config naming ~/.mosaic-NAME, a 0700 root and a 0644 marker", (t) => {
+    const home = tmp(t, "si-");
+    for (const name of ["alpha", "beta"]) {
+      const r = bootstrap(home, "--instance", name);
+      assert.equal(r.code, 0, r.err);
+      const cfg = cfgOf(home, name), root = join(home, `.mosaic-${name}`);
+      assert.equal(r.err, `mosaic-config: created configuration for instance ${name}: ${cfg}, data root ${root}\n`);
+      assert.equal(mode(join(home, ".config", `mosaic-${name}`)), 0o700);
+      assert.equal(mode(cfg), 0o644);
+      assert.equal(JSON.parse(readFileSync(cfg, "utf8")).dataRoot, root);
+      assert.equal(mode(root), 0o700);
+      const marker = join(root, "instance.json");
+      assert.equal(readFileSync(marker, "utf8"), `{"instanceVersion":1,"name":"${name}"}\n`);
+      assert.equal(mode(marker), 0o644);
+      assert.deepEqual(readdirSync(root), ["instance.json"]);
+      assert.deepEqual(readdirSync(join(home, ".config", `mosaic-${name}`)), ["config.json"]);
+    }
+    assert.equal(existsSync(join(home, ".config", "mosaic-dev")), false);
+    assert.equal(existsSync(join(home, ".mosaic-dev")), false);
+  });
+
+  await t.test("a second bootstrap of each changes no byte, mode or mtime", (t) => {
+    const home = tmp(t, "si-");
+    for (const name of ["alpha", "beta"]) assert.equal(bootstrap(home, "--instance", name).code, 0);
+    const before = snapshot(home);
+    for (const name of ["alpha", "beta"]) {
+      const r = bootstrap(home, "--instance", name);
+      assert.equal(r.code, 0, r.err);
+      assert.equal(r.err, `mosaic-config: configuration already present, validated without changes: ${cfgOf(home, name)}\n`);
+    }
+    assert.deepEqual(snapshot(home), before);
+  });
+
+  await t.test("a non-empty root without its own marker refuses before anything is written, worktrees included", (t) => {
+    const home = tmp(t, "si-");
+    mkdirSync(join(home, ".mosaic-gamma"));
+    writeFileSync(join(home, ".mosaic-gamma", "notes.txt"), "someone's data\n");
+    mkdirSync(join(home, ".mosaic-worktrees", "row190"), { recursive: true });
+    mkdirSync(join(home, ".mosaic-delta"));
+    writeFileSync(join(home, ".mosaic-delta", "instance.json"), `{"instanceVersion":1,"name":"alpha"}\n`);
+    writeFileSync(join(home, ".mosaic-delta", "other"), "x");
+    const before = snapshot(home);
+    for (const name of ["gamma", "worktrees", "delta"]) {
+      const r = bootstrap(home, "--instance", name);
+      assert.equal(r.code, 3, r.err);
+      assert.match(r.err, new RegExp(`instance-root-unclaimed: ${join(home, `.mosaic-${name}`)} exists, is not empty and holds no instance.json naming ${name}; nothing was written`));
+      assert.equal(existsSync(join(home, ".config", `mosaic-${name}`)), false);
+    }
+    assert.deepEqual(snapshot(home), before);
+    // A root that is a file refuses the same way.
+    writeFileSync(join(home, ".mosaic-file"), "x");
+    const r = bootstrap(home, "--instance", "file");
+    assert.equal(r.code, 3);
+    assert.match(r.err, /instance-root-unclaimed: .* exists and is not a directory; nothing was written/);
+    assert.equal(existsSync(join(home, ".config", "mosaic-file")), false);
+  });
+
+  await t.test("an empty existing root is claimed, and an existing config whose root lost its marker refuses, not repairs", (t) => {
+    const home = tmp(t, "si-");
+    mkdirSync(join(home, ".mosaic-alpha"), { mode: 0o700 });
+    assert.equal(bootstrap(home, "--instance", "alpha").code, 0);
+    assert.equal(readFileSync(join(home, ".mosaic-alpha", "instance.json"), "utf8"), `{"instanceVersion":1,"name":"alpha"}\n`);
+    rmSync(join(home, ".mosaic-alpha", "instance.json"));
+    const before = snapshot(home);
+    const r = bootstrap(home, "--instance", "alpha");
+    assert.equal(r.code, 3);
+    assert.match(r.err, /instance-root-unclaimed: .*\.mosaic-alpha holds no instance\.json naming alpha/);
+    assert.deepEqual(snapshot(home), before);
+  });
+
+  await t.test("a dangling symlink at the config path is never written through, named or default", (t) => {
+    const home = tmp(t, "si-");
+    for (const [name, args] of [["alpha", ["--instance", "alpha"]], ["dev", []]]) {
+      const dir = join(home, ".config", `mosaic-${name}`), target = join(home, `elsewhere-${name}.json`);
+      mkdirSync(dir, { recursive: true, mode: 0o700 });
+      symlinkSync(target, join(dir, "config.json"));
+      const r = bootstrap(home, ...args);
+      assert.equal(r.code, 2, `${name}: ${r.err}`);
+      assert.match(r.err, /configuration path must be a regular, non-symbolic-link file/);
+      assert.equal(existsSync(target), false, `${name}: the link's target was created`);
+      assert.deepEqual(readdirSync(dir), ["config.json"]);
+      assert.ok(lstatSync(join(dir, "config.json")).isSymbolicLink());
+    }
+    assert.deepEqual(readdirSync(home).sort(), [".config"]);
+  });
+
+  await t.test("bad names and stray arguments exit 4 and write nothing", (t) => {
+    const home = tmp(t, "si-");
+    for (const name of ["A", "a-b", "x", "a", "abcdefghijklmnopq", "../x", "1ab", "a.b", ""]) {
+      const r = bootstrap(home, "--instance", name);
+      assert.equal(r.code, 4, `${name}: ${r.err}`);
+      assert.match(r.err, /instance-name-invalid/);
+    }
+    assert.equal(bootstrap(home, "--instance", "abcdefghijklmnop").code, 0, "16 characters pass");
+    rmSync(join(home, ".config"), { recursive: true });
+    rmSync(join(home, ".mosaic-abcdefghijklmnop"), { recursive: true });
+    for (const args of [["--instance"], ["--instance", "alpha", "extra"], ["extra"], ["--name", "alpha"]]) {
+      const r = bootstrap(home, ...args);
+      assert.equal(r.code, 4, `${args.join(" ")}: ${r.err}`);
+      assert.match(r.err, /usage: mosaic-config\.mjs bootstrap \[--instance NAME\]/);
+    }
+    assert.deepEqual(readdirSync(home), []);
+  });
+
+  await t.test("--instance dev writes exactly what no flag writes", (t) => {
+    const plain = tmp(t, "si-"), dev = tmp(t, "si-");
+    const a = bootstrap(plain), b = bootstrap(dev, "--instance", "dev");
+    assert.equal(a.code, 0, a.err);
+    assert.equal(b.code, 0, b.err);
+    assert.equal(b.err.replaceAll(dev, "HOME"), a.err.replaceAll(plain, "HOME"));
+    const shape = (home) => Object.fromEntries(Object.entries(snapshot(home)).map(([k, v]) => [k, { ...v, mtime: 0, sha: v.sha && createHash("sha256").update(readFileSync(join(home, k), "utf8").replaceAll(home, "HOME")).digest("hex") }]));
+    assert.deepEqual(shape(dev), shape(plain));
+    assert.deepEqual(Object.keys(snapshot(plain)), [".config", ".config/mosaic-dev", ".config/mosaic-dev/config.json"]);
+  });
+});
+
+test("T-I2 selection: the four rows of D1 through the instance op and through an entry point", async (t) => {
+  const home = tmp(t, "si-");
+  for (const name of ["alpha", "beta"]) assert.equal(bootstrap(home, "--instance", name).code, 0);
+  const scratch = join(home, "scratch-config.json");
+  writeJson(scratch, { configVersion: 1, environment: "development", dataRoot: join(home, "scratch-data"), execution: { backend: "docker", provider: "zai", model: "glm-5.3-flash" } });
+
+  await t.test("row 1: no flag and no MOSAIC_CONFIG is the default; a missing default config leaves the data root empty", () => {
+    const r = config(home, {}, "instance");
+    assert.equal(r.code, 0, r.err);
+    assert.deepEqual(exportsOf(r.out), {
+      MOSAIC_INSTANCE: "dev",
+      MOSAIC_INSTANCE_CONFIG: cfgOf(home, "dev"),
+      MOSAIC_INSTANCE_CONFIG_DIR: join(home, ".config", "mosaic-dev"),
+      MOSAIC_INSTANCE_DATA_ROOT: "",
+      MOSAIC_UNIT_SUFFIX: "",
+    });
+    assert.deepEqual(exportsOf(config(home, {}, "instance", "--instance", "dev").out), exportsOf(r.out));
+  });
+
+  await t.test("row 2: MOSAIC_CONFIG alone is that config with the default names", () => {
+    const r = config(home, { MOSAIC_CONFIG: scratch }, "instance");
+    assert.equal(r.code, 0, r.err);
+    assert.deepEqual(exportsOf(r.out), {
+      MOSAIC_INSTANCE: "dev",
+      MOSAIC_INSTANCE_CONFIG: scratch,
+      MOSAIC_INSTANCE_CONFIG_DIR: home,
+      MOSAIC_INSTANCE_DATA_ROOT: join(home, "scratch-data"),
+      MOSAIC_UNIT_SUFFIX: "",
+    });
+  });
+
+  await t.test("row 3: --instance NAME alone is NAME's config, root and suffix", () => {
+    for (const name of ["alpha", "beta"]) {
+      const r = config(home, {}, "instance", "--instance", name);
+      assert.equal(r.code, 0, r.err);
+      assert.deepEqual(exportsOf(r.out), {
+        MOSAIC_INSTANCE: name,
+        MOSAIC_INSTANCE_CONFIG: cfgOf(home, name),
+        MOSAIC_INSTANCE_CONFIG_DIR: join(home, ".config", `mosaic-${name}`),
+        MOSAIC_INSTANCE_DATA_ROOT: join(home, `.mosaic-${name}`),
+        MOSAIC_UNIT_SUFFIX: `-${name}`,
+      });
+    }
+  });
+
+  await t.test("row 4: both must name one file; a symlink to it agrees, any other file exits 4", () => {
+    const link = join(home, "alpha-link.json");
+    symlinkSync(cfgOf(home, "alpha"), link);
+    for (const given of [cfgOf(home, "alpha"), link]) {
+      const r = config(home, { MOSAIC_CONFIG: given }, "instance", "--instance", "alpha");
+      assert.equal(r.code, 0, r.err);
+      assert.equal(exportsOf(r.out).MOSAIC_INSTANCE_CONFIG, cfgOf(home, "alpha"));
+    }
+    for (const given of [cfgOf(home, "beta"), scratch, join(home, "missing.json")]) {
+      for (const op of ["instance", "validate", "env", "bootstrap"]) {
+        const r = config(home, { MOSAIC_CONFIG: given }, op, "--instance", "alpha");
+        assert.equal(r.code, 4, `${op} ${given}: ${r.err}`);
+        assert.equal(r.out, "");
+        assert.match(r.err, new RegExp(`instance-config-mismatch: --instance alpha names ${cfgOf(home, "alpha")}, but MOSAIC_CONFIG names ${given}`));
+      }
+    }
+  });
+
+  await t.test("a named instance with no config exits 3 with its own bootstrap hint", () => {
+    const r = config(home, {}, "instance", "--instance", "gamma");
+    assert.equal(r.code, 3);
+    assert.match(r.err, /configuration not found: .*mosaic-gamma\/config\.json \(run scripts\/bootstrap\.sh --instance gamma to create it\)/);
+  });
+
+  await t.test("an entry point takes --instance in any position, once, and refuses a mismatch before it prints", () => {
+    const first = run(BUS_SERVICE, ["--instance", "alpha", "render"], homeEnv(home));
+    assert.equal(first.code, 0, first.err);
+    assert.match(first.out, new RegExp(`^Environment=MOSAIC_CONFIG=${cfgOf(home, "alpha")}$`, "m"));
+    assert.equal(run(BUS_SERVICE, ["render", "--instance", "alpha"], homeEnv(home)).out, first.out);
+    assert.equal(run(BUS_SERVICE, ["render", "--instance", "alpha"], homeEnv(home, { MOSAIC_CONFIG: cfgOf(home, "alpha") })).out, first.out);
+    const mismatch = run(BUS_SERVICE, ["--instance", "alpha", "render"], homeEnv(home, { MOSAIC_CONFIG: cfgOf(home, "beta") }));
+    assert.equal(mismatch.code, 4);
+    assert.equal(mismatch.out, "");
+    assert.match(mismatch.err, /instance-config-mismatch/);
+    for (const args of [["--instance", "alpha", "render", "--instance", "alpha"], ["render", "--instance"]]) {
+      const r = run(BUS_SERVICE, args, homeEnv(home));
+      assert.equal(r.code, 4, args.join(" "));
+      assert.equal(r.out, "");
+      assert.match(r.err, /instance: usage: --instance NAME, given once/);
+    }
+    const bad = run(BUS_SERVICE, ["--instance", "a-b", "render"], homeEnv(home));
+    assert.equal(bad.code, 4);
+    assert.match(bad.err, /instance-name-invalid/);
+  });
+
+  await t.test("copy takes no --instance in either script: every instance shares the copies", () => {
+    const copies = join(home, "copies-probe");
+    const before = snapshot(home);
+    for (const [cmd, args, err] of [
+      [STACK_COPY, ["--instance", "alpha", "copy", "HEAD", "--copies", copies], /^usage: stack-copy\.sh copy COMMIT/],
+      [STACK_COPY, ["copy", "HEAD", "--copies", copies, "--instance", "alpha"], /^usage: stack-copy\.sh copy COMMIT/],
+      [WEBUI_SERVICE, ["--instance", "alpha", "copy", "HEAD", "--copies", copies], /^webui-service: copy takes no --instance; every instance shares the copies\n$/],
+      [WEBUI_SERVICE, ["copy", "HEAD", "--copies", copies, "--instance", "alpha"], /^webui-service: copy takes no --instance; every instance shares the copies\n$/],
+    ]) {
+      const r = run(cmd, args, homeEnv(home));
+      assert.equal(r.code, 4, `${args.join(" ")}: ${r.err}`);
+      assert.equal(r.out, "");
+      assert.match(r.err, err, args.join(" "));
+    }
+    assert.deepEqual(snapshot(home), before);
+  });
+});
+
+test("T-I7 claims: the instance op refuses a root another instance claims, and a named root with no marker", async (t) => {
+  const home = tmp(t, "si-");
+  for (const name of ["alpha", "beta"]) assert.equal(bootstrap(home, "--instance", name).code, 0);
+  const edit = (name, dataRoot) => writeJson(cfgOf(home, name), { ...JSON.parse(readFileSync(cfgOf(home, name), "utf8")), dataRoot });
+  const scratch = join(home, "scratch-config.json");
+  const scratchRoot = join(home, "scratch-data");
+  writeJson(scratch, { configVersion: 1, environment: "development", dataRoot: scratchRoot, execution: { backend: "docker", provider: "zai", model: "glm-5.3-flash" } });
+
+  await t.test("alpha's config pointing at beta's root refuses instance-root-mismatch in every op", () => {
+    edit("alpha", join(home, ".mosaic-beta"));
+    for (const op of ["instance", "validate", "env", "bootstrap"]) {
+      const r = config(home, {}, op, "--instance", "alpha");
+      assert.equal(r.code, 3, `${op}: ${r.err}`);
+      assert.equal(r.out, "");
+      assert.match(r.err, new RegExp(`instance-root-mismatch: ${join(home, ".mosaic-beta")} is claimed by instance beta, not alpha`));
+    }
+    edit("alpha", join(home, ".mosaic-alpha"));
+    assert.equal(config(home, {}, "instance", "--instance", "alpha").code, 0);
+  });
+
+  await t.test("MOSAIC_CONFIG naming alpha's config with no flag refuses: the root is alpha's", () => {
+    for (const op of ["instance"]) {
+      const r = config(home, { MOSAIC_CONFIG: cfgOf(home, "alpha") }, op);
+      assert.equal(r.code, 3, r.err);
+      assert.match(r.err, new RegExp(`instance-root-mismatch: ${join(home, ".mosaic-alpha")} is claimed by instance alpha; select it with --instance alpha`));
+    }
+  });
+
+  await t.test("a default config whose root carries alpha's marker refuses; one naming dev, or none, passes", () => {
+    mkdirSync(scratchRoot, { recursive: true });
+    assert.equal(config(home, { MOSAIC_CONFIG: scratch }, "instance").code, 0, "no marker passes as today");
+    writeFileSync(join(scratchRoot, "instance.json"), `{"instanceVersion":1,"name":"alpha"}\n`);
+    const r = config(home, { MOSAIC_CONFIG: scratch }, "instance");
+    assert.equal(r.code, 3);
+    assert.match(r.err, /claimed by instance alpha; select it with --instance alpha/);
+    writeFileSync(join(scratchRoot, "instance.json"), `{"instanceVersion":1,"name":"dev"}\n`);
+    assert.equal(config(home, { MOSAIC_CONFIG: scratch }, "instance").code, 0);
+    rmSync(join(scratchRoot, "instance.json"));
+  });
+
+  await t.test("a named root whose marker is missing, a symlink, unparsable or the wrong shape refuses instance-root-unclaimed", () => {
+    const marker = join(home, ".mosaic-alpha", "instance.json");
+    const good = readFileSync(marker, "utf8");
+    const cases = [
+      ["missing", () => {}, /holds no instance\.json naming alpha/],
+      ["a symlink", () => { writeFileSync(join(home, "real-marker.json"), good); symlinkSync(join(home, "real-marker.json"), marker); }, /must be a regular, non-symbolic-link file/],
+      ["a directory", () => mkdirSync(marker), /must be a regular, non-symbolic-link file/],
+      ["unparsable", () => writeFileSync(marker, "{"), /is not a valid marker/],
+      ["an extra key", () => writeFileSync(marker, `{"instanceVersion":1,"name":"alpha","x":1}\n`), /is not a valid marker/],
+      ["version 2", () => writeFileSync(marker, `{"instanceVersion":2,"name":"alpha"}\n`), /is not a valid marker/],
+      ["a bad name", () => writeFileSync(marker, `{"instanceVersion":1,"name":"Alpha"}\n`), /is not a valid marker/],
+    ];
+    for (const [name, change, why] of cases) {
+      rmSync(marker, { recursive: true, force: true });
+      change();
+      const r = config(home, {}, "instance", "--instance", "alpha");
+      assert.equal(r.code, 3, `${name}: ${r.err}`);
+      assert.match(r.err, /instance-root-unclaimed/, name);
+      assert.match(r.err, why, name);
+      rmSync(marker, { recursive: true, force: true });
+      writeFileSync(marker, good);
+    }
+    assert.equal(config(home, {}, "instance", "--instance", "alpha").code, 0);
+  });
+});
+
+async function until(check, ms) {
+  const end = Date.now() + ms;
+  while (!check()) {
+    if (Date.now() > end) throw new Error("timed out");
+    await new Promise((r) => setTimeout(r, 50));
+  }
+}
+
+// One named instance in `home`, ready for `bus start acme --no-launch`: bootstrap, a business file in
+// its config dir, its own roles copy, the skills its roles name, and a notifier with no binding.
+function hostInstance(home, root, name) {
+  assert.equal(bootstrap(home, "--instance", name).code, 0);
+  const cfg = cfgOf(home, name), dataRoot = join(home, `.mosaic-${name}`);
+  const files = join(root, `${name}-files`);
+  const roles = rolesCopy(files);
+  const doc = businessDoc(files, "acme");
+  for (const r of Object.values(doc.roles)) r.vars = { harness: "pi", model: "glm-5.3-flash", thinking: "high", ...r.vars };
+  writeJson(join(home, ".config", `mosaic-${name}`, "businesses", "acme.json"), { ...doc, plugins: { ...doc.plugins, harness: ["pi", "claude-code"] } });
+  cpSync(REPO_SKILLS, join(dataRoot, "skills-enabled"), { recursive: true });
+  notifyConfig(dataRoot, "acme", null);
+  return { name, cfg, dataRoot, env: homeEnv(home, { MOSAIC_CONFIG: cfg, MOSAIC_ROLES_DIR: roles }) };
+}
+
+test("T-I5 two real bus hosts, one per instance, run at once and each answers from its own socket under its own root", async (t) => {
+  const root = tmp(t, "si-");
+  const home = join(root, "h");
+  mkdirSync(home);
+  const both = ["alpha", "beta"].map((name) => hostInstance(home, root, name));
+  for (const inst of both) {
+    const sock = join(inst.dataRoot, "bus", "broker.sock");
+    // The kernel's limit for a Unix socket path is 107 bytes (the row 177 lesson).
+    assert.ok(Buffer.byteLength(sock) <= 107, `socket path is ${Buffer.byteLength(sock)} bytes: ${sock}`);
+    inst.sock = sock;
+    inst.child = spawn(MOSAIC, ["bus", "start", "acme", "--no-launch"], { env: inst.env, stdio: ["ignore", "pipe", "pipe"] });
+    t.after(() => inst.child.exitCode === null && inst.child.kill("SIGKILL"));
+    inst.out = "";
+    inst.child.stdout.on("data", (b) => (inst.out += b));
+    inst.child.stderr.on("data", (b) => (inst.out += b));
+  }
+  for (const inst of both) await until(() => /bus host up: business acme.*\n/.test(inst.out) || inst.child.exitCode !== null, 30000);
+  for (const inst of both) {
+    assert.match(inst.out, new RegExp(`bus host up: business acme, socket ${inst.sock}, notifier off, launches disabled\n`), inst.out);
+    assert.ok(lstatSync(inst.sock).isSocket());
+  }
+  for (const inst of both) {
+    const r = run(MOSAIC, ["bus", "status", "--json"], inst.env);
+    assert.equal(r.code, 0, r.err);
+    const s = JSON.parse(r.out);
+    assert.equal(s.host.business, "acme");
+    assert.equal(s.host.pid, inst.child.pid);
+    assert.equal(s.host.live, true);
+    assert.equal(s.socket, true);
+    // The broker process under the host holds the writer lock.
+    assert.equal(s.writerLock.live, true);
+    inst.lockPid = s.writerLock.pid;
+  }
+  assert.notEqual(both[0].child.pid, both[1].child.pid);
+  assert.notEqual(both[0].lockPid, both[1].lockPid);
+  // Stopping alpha leaves beta up.
+  const [alpha, beta] = both;
+  const exitA = once(alpha.child, "exit");
+  const stopA = run(MOSAIC, ["bus", "stop"], alpha.env);
+  assert.equal(stopA.code, 0, stopA.err);
+  assert.match(stopA.out, new RegExp(`stopped bus host for acme \\(pid ${alpha.child.pid}\\)`));
+  assert.equal((await exitA)[0], 0, alpha.out);
+  assert.equal(beta.child.exitCode, null);
+  const still = JSON.parse(run(MOSAIC, ["bus", "status", "--json"], beta.env).out);
+  assert.equal(still.host.pid, beta.child.pid);
+  assert.equal(still.writerLock.pid, beta.lockPid);
+  assert.equal(still.writerLock.live, true);
+  assert.equal(existsSync(join(alpha.dataRoot, "bus", "writer.lock")), false);
+  const exitB = once(beta.child, "exit");
+  assert.equal(run(MOSAIC, ["bus", "stop"], beta.env).code, 0);
+  assert.equal((await exitB)[0], 0, beta.out);
+});
+
+test("T-I10 the guard protects every instance's config dir and data roots, even under a corrupt config", (t) => {
+  const root = tmp(t, "si-");
+  const home = join(root, "h");
+  mkdirSync(home);
+  for (const name of ["alpha", "beta"]) assert.equal(bootstrap(home, "--instance", name).code, 0);
+  // alpha's root moved by its operator; beta's config is broken.
+  const moved = join(root, "alpha-data");
+  mkdirSync(moved);
+  writeJson(cfgOf(home, "alpha"), { ...JSON.parse(readFileSync(cfgOf(home, "alpha"), "utf8")), dataRoot: moved });
+  writeFileSync(cfgOf(home, "beta"), "{ not json");
+  for (const dir of ["mosaic.bak", "mosaic", "mosaic-a-b", "mosaic-Alpha", "mosaic-x"]) mkdirSync(join(home, ".config", dir));
+  const guard = new LiveSessionGuard({ fixtureRoot: root, homes: [home] });
+  const refuses = [
+    [join(home, ".config", "mosaic-alpha", "x"), "stack instance alpha's config dir"],
+    [join(home, ".mosaic-alpha", "x"), "stack instance alpha's default data root"],
+    [join(moved, "sessions", "x"), "stack instance alpha's configured data root"],
+    [join(home, ".config", "mosaic-beta", "x"), "stack instance beta's config dir"],
+    [join(home, ".mosaic-beta", "x"), "stack instance beta's default data root"],
+    [join(home, ".config"), "stack instance alpha's config dir"],
+  ];
+  for (const [p, why] of refuses) {
+    assert.throws(() => guard.check({ workspace: p }, "bind"), (e) => e.message === `workspace overlaps ${why} (bind)`, p);
+  }
+  for (const dir of ["mosaic.bak", "mosaic", "mosaic-a-b", "mosaic-Alpha", "mosaic-x"]) {
+    assert.equal(guard.check({ workspace: join(home, ".config", dir, "x") }, "bind"), true, dir);
+  }
+  assert.equal(guard.check({ workspace: join(root, "work") }, "bind"), true);
+});
@@ -25,7 +25,8 @@ const script=(fn)=>`#!${NODE}\n(${fn})();\n`;
 // systemctl --user: unit state in $SD_STATE/units.json, every call in calls.log. A bus start runs
 // holder.cjs (the store held open in WAL mode, writer.lock, host.json) and, with --pm in the unit's
 // ExecStart, writes the `launched` journal line and the launches entry unless a pm-<copy> fault
-// names another case. Faults are files in $SD_STATE/faults named for the copy they hit.
+// names another case. Faults are files in $SD_STATE/faults named for the copy they hit. Units of a
+// named instance (row 190) run on their own data root and host files beside the default's.
 function systemctl(){
 const fs=process.getBuiltinModule('node:fs'),path=process.getBuiltinModule('node:path'),cp=process.getBuiltinModule('node:child_process'),crypto=process.getBuiltinModule('node:crypto');
 const sd=process.env.SD_STATE,data=process.env.SD_DATA,unitDir=path.join(process.env.XDG_CONFIG_HOME,'systemd','user');
@@ -37,12 +38,16 @@ function systemctl(){
 const save=(s)=>{fs.writeFileSync(stFile+'.tmp',JSON.stringify(s));fs.renameSync(stFile+'.tmp',stFile)};
 const sleep=(ms)=>Atomics.wait(new Int32Array(new SharedArrayBuffer(4)),0,0,ms);
 const alive=(pid)=>{try{const s=fs.readFileSync(`/proc/${pid}/stat`,'utf8');return s[s.lastIndexOf(')')+2]!=='Z'}catch{return false}};
- const isBus=(u)=>/^mosaic-bus@[a-z0-9-]+\.service$/.test(u),inst=(u)=>u.slice('mosaic-bus@'.length,-'.service'.length);
+ // Row 190: a bus unit is the default's mosaic-bus@B or instance NAME's mosaic-bus-NAME@B; %i is B.
+ const isBus=(u)=>/^mosaic-bus(-[a-z][a-z0-9]{1,15})?@[a-z0-9-]+\.service$/.test(u),inst=(u)=>u.slice(u.indexOf('@')+1,-'.service'.length);
 const unitFile=(u)=>{
-  const main=isBus(u)?'mosaic-bus@.service':u,file=path.join(unitDir,main);
+  const main=isBus(u)?u.replace(/@[^@]*$/,'@.service'):u,file=path.join(unitDir,main);
  if(!fs.existsSync(file))return null;
-  const drops=[];
-  for(const d of isBus(u)?[main+'.d',u+'.d']:[u+'.d']){const dir=path.join(unitDir,d);if(fs.existsSync(dir))for(const f of fs.readdirSync(dir).sort())if(f.endsWith('.conf'))drops.push(path.join(dir,f))}
+  // The drop-in directories in systemd's order: service.d, the name cut after each hyphen, then
+  // the template's and the unit's own.
+  const stem=main.slice(0,main.search(/@?\.service$/)),dirs=['service.d'],drops=[];
+  for(let i=0;i<stem.length;i++)if(stem[i]==='-')dirs.push(stem.slice(0,i+1)+'.service.d');
+  for(const d of [...dirs,...(isBus(u)?[main+'.d',u+'.d']:[u+'.d'])]){const dir=path.join(unitDir,d);if(fs.existsSync(dir))for(const f of fs.readdirSync(dir).sort())if(f.endsWith('.conf'))drops.push(path.join(dir,f))}
  const r={wd:'',exec:'',env:[],drops};
  for(const f of [file,...drops])for(let line of fs.readFileSync(f,'utf8').split('\n')){
   line=line.replace(/%i/g,isBus(u)?inst(u):'').replace(/%h/g,process.env.HOME);
@@ -51,17 +56,21 @@ function systemctl(){
  }
  return r;
 };
- const snap=(ev)=>{
-  const dir=path.join(data,'bus'),files={};
+ // A named instance's unit sets MOSAIC_CONFIG, and its bus works on that config's data root. A unit
+ // without it is the default's, on $SD_DATA. Each data root has its own host and launches files.
+ const dataOf=(f)=>{const c=f&&f.env.find((v)=>v.startsWith('MOSAIC_CONFIG='));return c?JSON.parse(fs.readFileSync(c.slice('MOSAIC_CONFIG='.length),'utf8')).dataRoot:data};
+ const perData=(d,n)=>path.join(sd,d===data?`${n}.json`:`${n}-${path.basename(d)}.json`);
+ const snap=(ev,d)=>{
+  const dir=path.join(d,'bus'),files={};
  try{for(const n of fs.readdirSync(dir).sort()){const p=path.join(dir,n),st=fs.statSync(p);if(st.isFile())files[n]=[st.size,st.mtimeMs,crypto.createHash('sha256').update(fs.readFileSync(p)).digest('hex')]}}catch{}
  fs.appendFileSync(path.join(sd,'snap.jsonl'),JSON.stringify({ev,files})+'\n');
 };
- const pm=(b,id,pid,off)=>{
+ const pm=(unit,d,id,pid,off)=>{
  let mode='';try{mode=fs.readFileSync(faultFile(`pm-${id}`),'utf8').trim()}catch{}
-  const now=Date.now()-off*1000,epoch=Math.floor(now/1000),at=new Date(now).toISOString(),run=`run-${pid}`,unit=`mosaic-bus@${b}.service`;
+  const b=inst(unit),now=Date.now()-off*1000,epoch=Math.floor(now/1000),at=new Date(now).toISOString(),run=`run-${pid}`;
  const line=(text)=>fs.appendFileSync(path.join(sd,'journal.jsonl'),JSON.stringify({epoch,unit,text})+'\n');
  const ok=()=>line(`launched pm-${b}: run ${run}, claude opus`);
-  const lf=path.join(sd,'launches.json');let list=[];try{list=JSON.parse(fs.readFileSync(lf,'utf8'))}catch{}
+  const lf=perData(d,'launches');let list=[];try{list=JSON.parse(fs.readFileSync(lf,'utf8'))}catch{}
  const entry=(o)=>list.push({run,business:b,live:true,startedAt:at,...o});
  line(`bus host up: business ${b}, socket /fixture/bus.sock, notifier off`);
  switch(mode){
@@ -107,26 +116,26 @@ function systemctl(){
 }
 if(verb==='start'){
  const u=rest[0],f=unitFile(u);if(!f){console.error(`Unit ${u} not found.`);process.exit(5)}
-  const s=load(),id=path.basename(f.wd);
+  const s=load(),id=path.basename(f.wd),d=dataOf(f);
  if(!isBus(u)){s[u]={state:'active',pid:null,wd:f.wd};save(s);process.exit(0)}
  if(fault(`start-dies-${id}`)){s[u]={state:'failed',pid:null,wd:f.wd};save(s);process.exit(0)}
  // Row 185 (T48): the copy's start writes one event before the holder opens the store, so the
  // store differs from a backup the run took before the start. The close leaves no -wal.
  if(fault(`start-writes-row-${id}`)){
-   const db=new (process.getBuiltinModule('node:sqlite').DatabaseSync)(path.join(data,'bus','bus.sqlite'));
+   const db=new (process.getBuiltinModule('node:sqlite').DatabaseSync)(path.join(d,'bus','bus.sqlite'));
   db.prepare('INSERT INTO events (at) VALUES (?)').run('2999-01-01T00:00:00.000Z');db.close();
  }
-  snap('start');
+  snap('start',d);
  const off=process.env.SD_CLOCK_OFFSET||'0';
  // The holder must not inherit stack-release.sh's lock (fd 9) or any other fd above 2.
  const close='for fd in /proc/self/fd/*; do n=${fd##*/}; [ "$n" -gt 2 ] && eval "exec $n>&-" 2>/dev/null; done; exec "$@"';
-  const ch=cp.spawn('bash',['-c',close,'holder',process.execPath,path.join(__dirname,'..','holder.cjs'),data,inst(u),sd,off],{detached:true,stdio:'ignore'});
+  const ch=cp.spawn('bash',['-c',close,'holder',process.execPath,path.join(__dirname,'..','holder.cjs'),d,inst(u),sd,off,perData(d,'host')],{detached:true,stdio:'ignore'});
  ch.unref();
  fs.appendFileSync(path.join(sd,'pids.log'),ch.pid+'\n');
  const ready=path.join(sd,`ready-${ch.pid}`),end=Date.now()+10000;
  while(!fs.existsSync(ready)){if(Date.now()>end){console.error('fixture holder did not start');process.exit(1)}sleep(20)}
  s[u]={state:'active',pid:ch.pid,wd:f.wd};save(s);
-  if(f.exec.split(' ').slice(1).includes('--pm'))pm(inst(u),id,ch.pid,Number(off));
+  if(f.exec.split(' ').slice(1).includes('--pm'))pm(u,d,id,ch.pid,Number(off));
  process.exit(0);
 }
 if(verb==='stop'){
@@ -138,17 +147,18 @@ function systemctl(){
  }
  if(st){s[u]={...st,state:'inactive',pid:null};save(s)}
  if(isBus(u)){
+   const d=dataOf(unitFile(u));
   // One-shot: the stop leaves an empty -wal or -shm beside the store, as an unclean close would.
-   for(const [name,ext] of [['stop-leaves-wal','-wal'],['stop-leaves-shm','-shm']])if(fault(name)){fs.rmSync(faultFile(name));fs.writeFileSync(path.join(data,'bus','bus.sqlite'+ext),'')}
+   for(const [name,ext] of [['stop-leaves-wal','-wal'],['stop-leaves-shm','-shm']])if(fault(name)){fs.rmSync(faultFile(name));fs.writeFileSync(path.join(d,'bus','bus.sqlite'+ext),'')}
   // One-shot (T45): the stop writes one row after any STAMP into the table the fault names, as a
   // write the bus made between rollback's count and its stop would. The close leaves no -wal.
   if(fault('stop-writes-row')){
    const t=fs.readFileSync(faultFile('stop-writes-row'),'utf8');fs.rmSync(faultFile('stop-writes-row'));
-    const db=new (process.getBuiltinModule('node:sqlite').DatabaseSync)(path.join(data,'bus','bus.sqlite'));
+    const db=new (process.getBuiltinModule('node:sqlite').DatabaseSync)(path.join(d,'bus','bus.sqlite'));
    db.exec(`CREATE TABLE IF NOT EXISTS ${t} (seq INTEGER PRIMARY KEY, at TEXT NOT NULL)`);
    db.prepare(`INSERT INTO ${t} (at) VALUES (?)`).run('2999-01-01T00:00:00.000Z');db.close();
   }
-   snap('stop');
+   snap('stop',d);
  }
  process.exit(0);
 }
@@ -178,10 +188,11 @@ function systemdAnalyze(){
 if(fs.existsSync(extra))console.log(fs.readFileSync(extra,'utf8'));
 }

-// The bus host: holds the store open in WAL mode until SIGTERM, as the broker does.
+// The bus host: holds the store open in WAL mode until SIGTERM, as the broker does. It writes its
+// status to the host file systemctl names for its data root.
 function holder(){
 const fs=process.getBuiltinModule('node:fs'),path=process.getBuiltinModule('node:path'),{DatabaseSync}=process.getBuiltinModule('node:sqlite');
- const [data,business,sd,offset]=process.argv.slice(2),bus=path.join(data,'bus');
+ const [data,business,sd,offset,host]=process.argv.slice(2),bus=path.join(data,'bus');
 fs.mkdirSync(bus,{recursive:true,mode:0o700});
 const db=new DatabaseSync(path.join(bus,'bus.sqlite'));
 if(!db.prepare("SELECT count(*) AS n FROM sqlite_master WHERE name='meta'").get().n){
@@ -191,7 +202,7 @@ function holder(){
  db.prepare("INSERT INTO meta VALUES ('schema_version', '3g')").run();
 }
 fs.writeFileSync(path.join(bus,'writer.lock'),String(process.pid));
- const at=new Date(Date.now()-Number(offset||0)*1000).toISOString(),host=path.join(sd,'host.json');
+ const at=new Date(Date.now()-Number(offset||0)*1000).toISOString();
 fs.writeFileSync(host+'.tmp',JSON.stringify({host:{business,pid:process.pid,live:true,startedAt:at,notifier:'ok'},boot:{ok:true,business,at}}));
 fs.renameSync(host+'.tmp',host);
 process.on('SIGTERM',()=>{db.close();fs.rmSync(path.join(bus,'writer.lock'),{force:true});process.exit(0)});
@@ -199,21 +210,24 @@ function holder(){
 setInterval(()=>{},1<<30);
 }

-// A copy's scripts/mosaic: bus status and launches list from what the holder and systemctl wrote.
+// A copy's scripts/mosaic: bus status and launches list from what the holder and systemctl wrote
+// for the data root of the config it runs under (row 190), the default's being $SD_DATA.
 function mosaicStub(){
 const fs=process.getBuiltinModule('node:fs'),path=process.getBuiltinModule('node:path');
 const id=path.basename(path.resolve(__dirname,'..')),sd=process.env.SD_STATE,a=process.argv.slice(2).join(' ');
 const fault=(n)=>fs.existsSync(path.join(sd,'faults',n));
+ let d=process.env.SD_DATA;try{d=JSON.parse(fs.readFileSync(process.env.MOSAIC_CONFIG,'utf8')).dataRoot}catch{}
+ const perData=(n)=>path.join(sd,d===process.env.SD_DATA?`${n}.json`:`${n}-${path.basename(d)}.json`);
 const alive=(pid)=>{try{const s=fs.readFileSync(`/proc/${pid}/stat`,'utf8');return s[s.lastIndexOf(')')+2]!=='Z'}catch{return false}};
 if(a==='bus status --json'){
  if(fault(`status-${id}`))process.exit(1);
  let s={host:null,boot:null};
-  try{s=JSON.parse(fs.readFileSync(path.join(sd,'host.json'),'utf8'));s.host.live=alive(s.host.pid)}catch{}
+  try{s=JSON.parse(fs.readFileSync(perData('host'),'utf8'));s.host.live=alive(s.host.pid)}catch{}
  console.log(JSON.stringify(s));
 }else if(a==='bus status')console.log(`bus: fixture status for ${id}`);
 else if(a==='launches list --json'){
  if(fault(`launches-${id}`))process.exit(1);
-  let l=[];try{l=JSON.parse(fs.readFileSync(path.join(sd,'launches.json'),'utf8'))}catch{}
+  let l=[];try{l=JSON.parse(fs.readFileSync(perData('launches'),'utf8'))}catch{}
  console.log(JSON.stringify(l));
 }else{console.error(`fixture mosaic: ${a}`);process.exit(4)}
 }
@@ -289,7 +303,7 @@ const posts=(e)=>readdirSync(e.data).filter((n)=>n.startsWith('bus.post-attempt-
 const backupSum=(e,act)=>readFileSync(join(e.data,'backups','stack',act,'SHA256SUMS'),'utf8').split(' ')[0];
 const commitLines=(range)=>git(repo,'log','--oneline','--no-merges','--max-count=200',range).split('\n').map((l)=>`  ${l}`);
 // The units, the wrapper, the pointer and the store, by sha256.
-const fp=(e)=>({bus:sha(join(e.units,'[email protected]')),console:sha(join(e.units,CON)),wrapper:sha(join(e.bin,'mosaic')),pointer:existsSync(e.pointer)?sha(e.pointer):null,store:sha(e.store)});
+const fp=(e)=>({bus:sha(join(e.units,e.tmpl)),console:sha(join(e.units,e.con)),wrapper:sha(join(e.bin,e.wrapper)),pointer:existsSync(e.pointer)?sha(e.pointer):null,store:sha(e.store)});
 // The schema version: readOnly while the holder has the store open, immutable when it is stopped.
 function storeVersion(file,held){
 const db=held?new DatabaseSync(file,{readOnly:true}):new DatabaseSync(pathToFileURL(file).href+'?immutable=1',{readOnly:true});
@@ -317,6 +331,8 @@ function biz(e,plugins){
 async function mk(t){
 const root=realpathSync(mkdtempSync(join(tmpdir(),'sr-')));
 const e={root,data:join(root,'data'),bin:join(root,'bin'),sd:join(root,'sd'),units:join(root,'xcfg','systemd','user'),cfg:join(root,'cfg','config.json'),claude:join(root,'claude-bin','claude')};
+ // The default instance's names; named() sets NAME's (row 190).
+ Object.assign(e,{flags:[],bus:BUS,tmpl:'[email protected]',con:CON,wrapper:'mosaic'});
 Object.assign(e,{state:join(e.data,'state'),pointer:join(e.data,'state','stack-active.json'),log:join(e.data,'state','stack-activation-log.jsonl'),store:join(e.data,'bus','bus.sqlite'),lock:join(e.data,'state','stack-release.lock')});
 for(const d of [join(root,'home'),dirname(e.cfg),join(e.data,'bus'),e.bin,dirname(e.claude),join(e.sd,'faults'),e.units,join(root,'xdata')])mkdirSync(d,{recursive:true});
 chmodSync(join(e.data,'bus'),0o700);
@@ -326,25 +342,47 @@ async function mk(t){
 writeFileSync(join(e.bin,'mosaic-old'),'#!/bin/sh\nexit 0\n',{mode:0o755});
 writeFileSync(e.claude,'#!/bin/sh\necho "9.9.9 (Claude Code fixture)"\n',{mode:0o755});
 e.env={PATH:`${SBIN}:${dirname(NODE)}:/usr/bin:/bin`,HOME:join(root,'home'),XDG_CONFIG_HOME:join(root,'xcfg'),XDG_DATA_HOME:join(root,'xdata'),MOSAIC_CONFIG:e.cfg,SD_STATE:e.sd,SD_DATA:e.data,TMPDIR:tmpdir()};
- // The Console's /healthz: 200 while the stand-in has it active and no healthz-<copy> fault names its copy.
- const server=createServer((q,r)=>{
-  let st={};try{st=units(e)[CON]||{}}catch{}
-  const ok=q.url==='/healthz'&&st.state==='active'&&!existsSync(join(e.sd,'faults',`healthz-${basename(st.wd||'')}`));
-  r.writeHead(ok?200:500);r.end();
- });
- server.listen(0,'127.0.0.1');await once(server,'listening');e.port=String(server.address().port);
+ const server=await healthz(e);
 t.after(()=>{
  for(const pid of lines(join(e.sd,'pids.log')).map(Number)){
   try{if(readFileSync(`/proc/${pid}/cmdline`,'utf8').includes(join(base,'holder.cjs')))process.kill(pid,'SIGKILL')}catch{}
  }
-  server.close();execFileSync('chmod',['-R','u+w',root]);rmSync(root,{recursive:true,force:true});
+  for(const s of [server,...(e.servers??[])])s.close();
+  execFileSync('chmod',['-R','u+w',root]);rmSync(root,{recursive:true,force:true});
 });
 return e;
 }

+// The Console's /healthz on e.port: 200 while the stand-in has e.con active and no healthz-<copy>
+// fault names its copy.
+async function healthz(e){
+ const server=createServer((q,r)=>{
+  let st={};try{st=units(e)[e.con]||{}}catch{}
+  const ok=q.url==='/healthz'&&st.state==='active'&&!existsSync(join(e.sd,'faults',`healthz-${basename(st.wd||'')}`));
+  r.writeHead(ok?200:500);r.end();
+ });
+ server.listen(0,'127.0.0.1');await once(server,'listening');e.port=String(server.address().port);
+ return server;
+}
+
+// Row 190: stack instance NAME on e's host. It shares e's stand-ins, unit directory and $BIN, and has
+// its own config and data root from bootstrap --instance, its own Console port and business acme.
+// Its runs pass --instance NAME and no MOSAIC_CONFIG.
+async function named(e,name){
+ const env={...e.env};delete env.MOSAIC_CONFIG;
+ execFileSync('bash',[join(repo,'scripts','bootstrap.sh'),'--instance',name],{env,stdio:'ignore'});
+ const data=join(env.HOME,`.mosaic-${name}`);
+ const n={...e,env,data,cfg:join(env.HOME,'.config',`mosaic-${name}`,'config.json'),flags:['--instance',name],bus:`mosaic-bus-${name}@acme.service`,tmpl:`mosaic-bus-${name}@.service`,con:`mosaic-webui-${name}.service`,wrapper:`mosaic-${name}`,name};
+ Object.assign(n,{state:join(data,'state'),pointer:join(data,'state','stack-active.json'),log:join(data,'state','stack-activation-log.jsonl'),store:join(data,'bus','bus.sqlite'),lock:join(data,'state','stack-release.lock')});
+ mkdirSync(join(data,'bus'),{mode:0o700});
+ biz(n);
+ (e.servers??=[]).push(await healthz(n));
+ return n;
+}
+
 async function run(e,...args){
 const before=existsSync(e.data)?kept(e):[];
- const ch=spawn('bash',[e.sr??SR,...args,'--copies',COPIES,'--bin',e.bin],{env:e.env,stdio:['ignore','pipe','pipe']});
+ const ch=spawn('bash',[e.sr??SR,...args,...e.flags,'--copies',COPIES,'--bin',e.bin],{env:e.env,stdio:['ignore','pipe','pipe']});
 let out='',err='';ch.stdout.on('data',(d)=>{out+=d});ch.stderr.on('data',(d)=>{err+=d});
 const timer=setTimeout(()=>ch.kill('SIGKILL'),120000);
 const [code]=await once(ch,'close');clearTimeout(timer);
@@ -364,12 +402,12 @@ async function seed(e,{copy=B,pm=false,store='3g',pointer:how='adopt'}={}){
 for(let i=0;i<3;i++)db.prepare('INSERT INTO events (at) VALUES (?)').run(`2000-01-01T00:00:0${i}.000Z`);
 db.close();
 const sh=(name,...a)=>execFileSync('bash',[join(repo,'scripts',name),...a],{env:e.env,encoding:'utf8',stdio:['ignore','pipe','pipe']});
- sh('bus-service.sh','install','--copy',copy,'--copies',COPIES,...(pm?['--pm']:[]),'--claude',e.claude);
- sh('webui-service.sh','install','--copy',copy,'--copies',COPIES,'--port',e.port,'--business','acme');
- sh('stack-copy.sh','wrapper',copy,'--copies',COPIES,'--bin',e.bin);
+ sh('bus-service.sh','install',...e.flags,'--copy',copy,'--copies',COPIES,...(pm?['--pm']:[]),'--claude',e.claude);
+ sh('webui-service.sh','install',...e.flags,'--copy',copy,'--copies',COPIES,'--port',e.port,'--business','acme');
+ sh('stack-copy.sh','wrapper',copy,...e.flags,'--copies',COPIES,'--bin',e.bin);
 // The seeded host started two minutes ago, so its boot status and PM run predate any run's start.
- execFileSync(join(SBIN,'systemctl'),['--user','start',BUS],{env:{...e.env,SD_CLOCK_OFFSET:'120'}});
- sysctl(e,'start',CON);
+ execFileSync(join(SBIN,'systemctl'),['--user','start',e.bus],{env:{...e.env,SD_CLOCK_OFFSET:'120'}});
+ sysctl(e,'start',e.con);
 if(how==='adopt'){const r=await run(e,'adopt','acme');assert.equal(r.code,0,r.err)}
 else if(how==='hand'){
  mkdirSync(e.state,{recursive:true});
@@ -381,7 +419,7 @@ async function seed(e,{copy=B,pm=false,store='3g',pointer:how='adopt'}={}){
 const rolledBack=(code,to=B)=>`stack-release: ${code}; rolled back to ${to}, which passed the gate\n`;
 const planBackup=(e)=>`backup: the run backs up the stopped store to ${e.data}/backups/stack/<activation>/ before any migration`;
 const planNoBackup='backup: none; the run rolls back before the backup';
-const planTail=(e,to,pm=false)=>[`bus: scripts/bus-service.sh install --copy ${to} --copies ${COPIES}${pm?' --pm':''} --claude ${e.claude}`,'proof: off',`Console: scripts/webui-service.sh install --copy ${to} --copies ${COPIES} --port ${e.port} --business acme`,`CLI: scripts/stack-copy.sh wrapper ${to} --copies ${COPIES} --bin ${e.bin}`];
+const planTail=(e,to,pm=false)=>[`bus: scripts/bus-service.sh install --copy ${to} --copies ${COPIES}${pm?' --pm':''} --claude ${e.claude}`,'proof: off','send: off',`Console: scripts/webui-service.sh install --copy ${to} --copies ${COPIES} --port ${e.port} --business acme`,`CLI: scripts/stack-copy.sh wrapper ${to} --copies ${COPIES} --bin ${e.bin}`];

 // --- The T table ---

@@ -1030,17 +1068,17 @@ test('T36 --plan shows the pending state and lists the row 169 refusals it can s
  return r.out.split('\n');
 };
 let out=await quiet(0,'activate',C1,'acme','--pm-after-harness','--plan');
- assert.deepEqual(out.slice(-6),['pm: the bus starts without --pm and the PM stays pending; next: Jason\'s plugins set of harness, then pm-on',...planTail(e,C1),'']);
+ assert.deepEqual(out.slice(-7),['pm: the bus starts without --pm and the PM stays pending; next: Jason\'s plugins set of harness, then pm-on',...planTail(e,C1),'']);
 biz(e,HARNESS);
 out=await quiet(3,'activate',A,'acme','--pm-after-harness','--plan');
- assert.deepEqual(out.slice(-7),['pm: the bus starts without --pm and the PM stays pending; next: Jason\'s plugins set of harness, then pm-on',...planTail(e,A),`refuses unknown-kind-for-target: the business file names plug-in kind(s) harness, which ${A} does not know`,'']);
+ assert.deepEqual(out.slice(-8),['pm: the bus starts without --pm and the PM stays pending; next: Jason\'s plugins set of harness, then pm-on',...planTail(e,A),`refuses unknown-kind-for-target: the business file names plug-in kind(s) harness, which ${A} does not know`,'']);
 out=await quiet(3,'activate',C1,'acme','--pm-after-harness','--plan');
 assert.equal(out.at(-2),'refuses pm-after-harness-set: the business file already sets harness ["claude-code"]; use --pm');
 biz(e);assert.equal((await run(e,'activate',C1,'acme','--pm-after-harness')).code,0);
 out=await quiet(3,'activate',C,'acme','--plan');
- assert.deepEqual(out.slice(-7),['pm: the pointer is pending (activate --pm-after-harness); the bus runs without its PM',...planTail(e,C,true),`refuses pm-pending: ${PENDING_MSG}`,'']);
+ assert.deepEqual(out.slice(-8),['pm: the pointer is pending (activate --pm-after-harness); the bus runs without its PM',...planTail(e,C,true),`refuses pm-pending: ${PENDING_MSG}`,'']);
 out=await quiet(0,'rollback','acme','--plan');
- assert.deepEqual(out.slice(-6),['pm: the pointer is pending (activate --pm-after-harness); the bus runs without its PM',...planTail(e,B,true),'']);
+ assert.deepEqual(out.slice(-7),['pm: the pointer is pending (activate --pm-after-harness); the bus runs without its PM',...planTail(e,B,true),'']);
 });

 // Row 176 test 11: supported and older Console copies deliberately differ from the checkout.
@@ -1706,6 +1744,113 @@ test('T54 row 188: a carried pair gets the proof file checks, and a proof file i
 });
 });

+// Row 189 (#1687, mos-0972/0973): activate --no-send drops the pointer's --send; nothing turns it back on.
+const sendLines=(out)=>out.filter((l)=>l.startsWith('send:'));
+const noSend=(c)=>c.filter((x)=>x!=='--send');
+const LIVE_NOTE=`note: ${B} is the pointer's copy; the run re-pins it and only the Console flags change`;
+test('T55 row 189: activate --no-send drops --send, and rollback and pm-on carry it off',async(t)=>{
+ await t.test('test 1: a live-copy --no-send drops --send from the pointer and the unit, keeps the rest in order, logs the step and backs up the stopped store',async(t)=>{
+  const e=await mk(t),base=await seedPreview(e,undefined,['--send','--tester-port','7333']),want=noSend(base);
+  assert.deepEqual(want.slice(-2),['--tester-port','7333']);
+  const sum=createHash('sha256').update(readFileSync(e.store)).digest('hex'),n=calls(e).length;
+  let r=await prun(e,'activate',B,'acme','--no-send');assert.equal(r.code,0,r.out+r.err);
+  assert.equal(pointer(e).copy,B);assert.deepEqual(pointer(e).console,want);
+  assert.ok(conExec(e).endsWith(` --checkout ${repo} ${want.join(' ')}`),conExec(e));assert.doesNotMatch(conExec(e),/ --send( |$)/);
+  r=await prun(e,'status','acme');assert.equal(r.code,0,r.err);assert.match(r.out,/unit flags: match the pointer/);
+  assert.match(stepText(e),/Z drop --send; --no-send was given\n/);
+  const act=pointer(e).activation,l=logLines(e).at(-1);
+  assert.deepEqual([l.op,l.from,l.to,l.result,l.backup],['activate',B,B,'ok',act]);assert.equal(backupSum(e,act),sum);
+  assert.deepEqual(startsStops(e,n),[`stop ${CON}`,`stop ${BUS}`,`start ${BUS}`,`start ${CON}`]);
+  await noLeak(e);
+ });
+ await t.test('test 2: a plain live-copy activate still refuses already-active, and so does --no-send once --send is gone',async(t)=>{
+  const e=await mk(t);await seedPreview(e,undefined,['--send']);
+  await refused(e,['activate',B,'acme'],'already-active',`${B} is the pointer's copy`);
+  await refused(e,['activate',B,'acme','--tester-port','7333'],'already-active',`${B} is the pointer's copy`);
+  await refused(e,['activate',B,'acme','--no-proof'],'already-active',`${B} is the pointer's copy`);
+  const r=await prun(e,'activate',B,'acme','--no-send');assert.equal(r.code,0,r.out+r.err);
+  await refused(e,['activate',B,'acme','--no-send'],'already-active',`${B} is the pointer's copy`);
+  const g=await mk(t);await seedPreview(g);
+  await refused(g,['activate',B,'acme','--no-send'],'already-active',`${B} is the pointer's copy`);
+  for(const x of [e,g])await noLeak(x);
+ });
+ await t.test('test 3: --plan prints one send: line in each case, with the live-copy note on a same-copy run',async(t)=>{
+  const e=await mk(t),base=await seedPreview(e,undefined,['--send']);
+  let out=await planOnly(e,0,'activate',B,'acme','--no-send');
+  assert.deepEqual(sendLines(out),['send: dropped; --no-send was given']);
+  assert.deepEqual(out.filter((l)=>l.startsWith('note: ')),[LIVE_NOTE]);
+  assert.equal(out[out.indexOf('send: dropped; --no-send was given')+1],`Console: scripts/webui-service.sh install --copy ${B} --copies ${COPIES} ${noSend(base).join(' ')}`);
+  out=await planOnly(e,0,'activate',C1,'acme');
+  assert.deepEqual(sendLines(out),['send: carried']);assert.deepEqual(out.filter((l)=>l.startsWith('note: ')),[]);
+  assert.ok(out.find((l)=>l.startsWith('Console: ')).endsWith(' --send'));
+  assert.deepEqual(sendLines(await planOnly(e,0,'activate',C1,'acme','--no-send')),['send: dropped; --no-send was given']);
+  let r=await prun(e,'activate',C1,'acme','--no-send');assert.equal(r.code,0,r.out+r.err);
+  assert.deepEqual(pointer(e).console,noSend(base));assert.match(stepText(e),/Z drop --send; --no-send was given\n/);
+  assert.deepEqual(sendLines(await planOnly(e,0,'activate',B,'acme','--no-send')),['send: off; --no-send was given and the pointer holds no --send']);
+  assert.deepEqual(sendLines(await planOnly(e,0,'activate',B,'acme')),['send: off']);
+  assert.deepEqual(sendLines(await planOnly(e,0,'rollback','acme')),['send: off']);
+  r=await prun(e,'activate',B,'acme','--no-send');assert.equal(r.code,0,r.out+r.err);
+  assert.match(stepText(e),/Z --no-send was given and the pointer holds no --send, so there is nothing to drop\n/);
+  assert.doesNotMatch(stepText(e),/drop --send/);
+  await noLeak(e);
+ });
+ await t.test('test 4: after --no-send, a rollback to the earlier copy leaves --send out of the pointer and the unit',async(t)=>{
+  const e=await mk(t),base=await seedPreview(e,undefined,['--send']);
+  let r=await prun(e,'activate',C1,'acme','--no-send');assert.equal(r.code,0,r.out+r.err);
+  r=await prun(e,'rollback','acme');assert.equal(r.code,0,r.out+r.err);
+  assert.equal(pointer(e).copy,B);assert.deepEqual(pointer(e).console,noSend(base));assert.doesNotMatch(conExec(e),/ --send( |$)/);
+  assert.doesNotMatch(stepText(e),/--send/);
+  r=await prun(e,'status','acme');assert.equal(r.code,0,r.err);assert.match(r.out,/unit flags: match the pointer/);
+  await noLeak(e);
+ });
+ await t.test('test 4: pm-on after --no-send keeps --send off',async(t)=>{
+  const e=await mk(t),base=await seedPreview(e,{pm:true},['--send']);
+  let r=await prun(e,'activate',C1,'acme','--pm-after-harness','--no-send');assert.equal(r.code,0,r.out+r.err);
+  biz(e,HARNESS);
+  r=await prun(e,'pm-on','acme');assert.equal(r.code,0,r.out+r.err);
+  assert.equal(pointer(e).pm,true);assert.deepEqual(pointer(e).console,noSend(base));assert.doesNotMatch(conExec(e),/ --send( |$)/);
+  r=await prun(e,'status','acme');assert.equal(r.code,0,r.err);assert.match(r.out,/unit flags: match the pointer/);
+  await noLeak(e);
+ });
+ await t.test('test 5: --no-send on rollback, pm-on, status, adopt or rehearse is a usage error',async(t)=>{
+  const e=await mk(t);await seedPreview(e,undefined,['--send']);
+  const usageText=(await prun(e,'--help')).err,n=calls(e).length,logs=logLines(e).length,before=fp(e);
+  for(const args of [['rollback','acme','--no-send'],['rollback','acme','--plan','--no-send'],['pm-on','acme','--no-send'],['status','acme','--no-send'],['adopt','acme','--no-send'],
+   ['rehearse','acme','--backup','/tmp/x','--port','7400','--no-send']]){
+   const r=await prun(e,...args);assert.equal(r.code,4,args.join(' '));assert.equal(r.out,'');assert.equal(r.err,usageText);
+  }
+  assert.match(usageText,/\| --no-proof\] \[--no-send\]/);
+  assert.deepEqual(fp(e),before);assert.deepEqual(startsStops(e,n),[]);assert.equal(logLines(e).length,logs);
+  await noLeak(e);
+ });
+ await t.test('test 6: with both a pair and --send in the pointer, --no-send and --no-proof each drop what they name and keep the rest',async(t)=>{
+  const e=await mk(t),base=await seedPreview(e,undefined,['--send']),pre=noSend(base),f=await proofFile(e),g=await proofFile(e,'proof2.189',0o400);
+  let r=await prun(e,'activate',B,'acme',...pair(f));assert.equal(r.code,0,r.out+r.err);
+  assert.deepEqual(pointer(e).console,[...pre,...pair(f),'--send']);
+  let out=await planOnly(e,0,'activate',C1,'acme','--no-proof');
+  assert.deepEqual([...proofLines(out),...sendLines(out)],['proof: dropped; --no-proof drops header x-console-proof','send: carried']);
+  out=await planOnly(e,0,'activate',C1,'acme','--no-send');
+  assert.deepEqual([...proofLines(out),...sendLines(out)],['proof: carried, header x-console-proof','send: dropped; --no-send was given']);
+  out=await planOnly(e,0,'activate',B,'acme','--no-send','--no-proof');
+  assert.deepEqual([...proofLines(out),...sendLines(out)],['proof: dropped; --no-proof drops header x-console-proof','send: dropped; --no-send was given']);
+  r=await prun(e,'activate',C1,'acme','--no-send');assert.equal(r.code,0,r.out+r.err);
+  assert.deepEqual(pointer(e).console,[...pre,...pair(f)]);
+  r=await prun(e,'activate',C1,'acme','--no-send',...pair(g,'X-Proof-Two'));assert.equal(r.code,0,r.out+r.err);
+  assert.deepEqual(pointer(e).console,[...pre,...pair(g,'X-Proof-Two')]);
+  r=await prun(e,'status','acme');assert.equal(r.code,0,r.err);assert.match(r.out,/unit flags: match the pointer/);
+  const h=await mk(t),hbase=await seedPreview(h,undefined,['--send']),hpre=noSend(hbase),k=await proofFile(h);
+  r=await prun(h,'activate',B,'acme',...pair(k));assert.equal(r.code,0,r.out+r.err);
+  r=await prun(h,'activate',C1,'acme','--no-proof');assert.equal(r.code,0,r.out+r.err);
+  assert.deepEqual(pointer(h).console,[...hpre,'--send']);
+  r=await prun(h,'activate',C1,'acme','--no-send','--no-proof');assert.equal(r.code,0,r.out+r.err);
+  assert.deepEqual(pointer(h).console,hpre);assert.doesNotMatch(conExec(h),/--proof-| --send( |$)/);
+  const steps=stepText(h);
+  assert.match(steps,/Z --no-proof was given and the pointer holds no proof pair, so there is nothing to drop\n/);assert.match(steps,/Z drop --send; --no-send was given\n/);
+  r=await prun(h,'status','acme');assert.equal(r.code,0,r.err);assert.match(r.out,/unit flags: match the pointer/);
+  for(const x of [e,h])await noLeak(x);
+ });
+});
+
 // --- rehearse (D2, row 163; the brief's "Stack rehearsal on a scratch root") ---
 // Copies of their own in RCOPIES: the real scripts/mosaic, config loader, business loader, roles and
 // mosaic-config.mjs, with stand-ins for the bus host (cli.mjs), the Console, the Store and
@@ -2084,3 +2229,160 @@ test('R15 a rehearsal stopped by TERM, INT or HUP fails signal and still stops t
  assert.equal(existsSync(`/proc/${pid}`),false,`${sig}: host pid ${pid} is still there`);
 }
 });
+
+// --- Row 190 (#1688): stack instances on one host. Design and the T-I table:
+// agents/darkwing/work/queue-190/DESIGN.md. T-I1, T-I2, T-I5, T-I10 and the loader half of T-I7 are in
+// stack-instances.test.mjs; these need the units, the stand-ins and stack-release.sh. Every existing
+// test above is D1's "no flag, no marker" case and passes unchanged.
+
+const shOut=(env,name,...a)=>spawnSync('bash',[join(repo,'scripts',name),...a],{env,encoding:'utf8'});
+// The Console template's comment on the variables its unit sets, as the default and a named instance render it.
+const CONSOLE_VARS={
+ default:'# and 94). The unit sets no MOSAIC_*, CLAUDE*, CODEX* or PI_* variable.',
+ named:'# and 94). The unit sets MOSAIC_CONFIG and no other MOSAIC_*, CLAUDE*, CODEX* or PI_* variable.',
+};
+const SHARED_DROPINS=['mosaic-bus-.service.d','mosaic-webui-.service.d','mosaic-discord-.service.d'];
+// Every path under each of ps with its mode, size, mtime and, for a file, its sha256.
+function stamp(...ps){
+ const out=[];
+ const walk=(q)=>{let st;try{st=lstatSync(q)}catch{out.push(`${q} absent`);return}
+  out.push(`${q} ${st.mode.toString(8)} ${st.size} ${st.mtimeMs}${st.isFile()?' '+sha(q):''}`);
+  if(st.isDirectory())for(const n of readdirSync(q).sort())walk(join(q,n))};
+ for(const p of ps)walk(p);return out;
+}
+const dirsUnder=(p)=>stamp(p).filter((l)=>!l.endsWith(' absent')).map((l)=>l.split(' ')[0]).filter((q)=>lstatSync(q).isDirectory());
+// The T53 inotify watch on a directory: it counts each open or read of the directory or a file in it.
+async function watchDir(e,d){
+ const ch=spawn('python3',['-I','-c',WATCH,d],{stdio:['pipe','pipe','inherit']});
+ let out='';ch.stdout.on('data',(b)=>{out+=b});
+ await new Promise((res,rej)=>{ch.stdout.on('data',()=>{if(out.startsWith('ready\n'))res()});ch.on('error',rej);ch.on('close',(c)=>rej(new Error(`inotify watch exited ${c}`)))});
+ WATCHERS.add(ch);ch.on('close',()=>WATCHERS.delete(ch));
+ (e.watches??=[]).push(async()=>{ch.stdin.end();if(ch.exitCode===null)await once(ch,'close');return [d,Number(out.split('\n')[1])]});
+}
+
+test('T56 row 190: named instances side by side on one unit directory, $BIN and set of stand-ins',async(t)=>{
+ await t.test('T-I3 each instance renders its own config, session env and Description, and nothing of another',async(t)=>{
+  const e=await mk(t),a=await named(e,'alpha'),b=await named(e,'beta');
+  for(const [x,y] of [[a,b],[b,a]]){
+   const renders={
+    bus:shOut(x.env,'bus-service.sh','render','--instance',x.name,'--copy',B,'--copies',COPIES,'--claude',e.claude),
+    console:shOut(x.env,'webui-service.sh','render','--instance',x.name,'--copy',B,'--copies',COPIES,'--port',x.port,'--business','acme'),
+    discord:shOut(x.env,'discord-service.sh','render','--instance',x.name),
+   };
+   for(const [k,r] of Object.entries(renders)){
+    assert.equal(r.status,0,`${x.name} ${k}: ${r.stderr}`);
+    assert.ok(r.stdout.includes(`\nEnvironment=MOSAIC_CONFIG=${x.cfg}\n`),`${x.name} ${k}`);
+    assert.match(r.stdout,new RegExp(`\\nDescription=[^\\n]* \\[${x.name}\\]\\n`),`${x.name} ${k}`);
+    for(const not of [y.name,'mosaic-dev'])assert.ok(!r.stdout.includes(not),`${x.name} ${k} holds ${not}`);
+   }
+   assert.ok(renders.bus.stdout.includes(`\nEnvironmentFile=-${dirname(x.cfg)}/secrets/claude-session.env\n`),x.name);
+   assert.ok(renders.console.stdout.includes(`\n${CONSOLE_VARS.named}\n`),x.name);
+   assert.ok(!renders.console.stdout.includes('sets no MOSAIC_'),x.name);
+   assert.equal(renders.bus.stdout.match(/^Environment(File)?=.*$/gm).filter((l)=>l.includes('MOSAIC_CONFIG')||l.startsWith('EnvironmentFile')).length,2,x.name);
+  }
+  // Sage's N3 ruling: the default Console keeps the template's comment byte for byte.
+  const dflt=shOut(e.env,'webui-service.sh','render','--copy',B,'--copies',COPIES,'--business','acme');
+  assert.equal(dflt.status,0,dflt.stderr);
+  assert.ok(dflt.stdout.includes(`\n${CONSOLE_VARS.default}\n`),dflt.stdout);
+  assert.ok(!dflt.stdout.includes('MOSAIC_CONFIG'),dflt.stdout);
+  // Filbert round 2: under --sso the Console reads console.sso from the config MOSAIC_CONFIG names (row 192),
+  // so a named --sso render carries both.
+  const sso=shOut(a.env,'webui-service.sh','render','--instance',a.name,'--copy',B,'--copies',COPIES,'--port',a.port,'--business','acme','--sso');
+  assert.equal(sso.status,0,sso.stderr);
+  assert.match(sso.stdout,/^ExecStart=.* --sso(?: |$)/m,sso.stdout);
+  assert.ok(sso.stdout.includes(`\nEnvironment=MOSAIC_CONFIG=${a.cfg}\n`),sso.stdout);
+  await seed(a);await seed(b);
+  for(const x of [a,b]){
+   const r=shOut(x.env,'discord-service.sh','install','--instance',x.name,'--dir',e.units,'--no-reload');assert.equal(r.status,0,r.stderr);
+   for(const u of [x.tmpl,x.con,`mosaic-discord-${x.name}@.service`])assert.ok(existsSync(join(e.units,u)),u);
+  }
+  assert.deepEqual(readdirSync(e.units).sort(),[a.tmpl,a.con,`[email protected]`,b.tmpl,b.con,`[email protected]`].sort());
+  for(const x of [a,b])assert.equal(readFileSync(join(e.bin,x.wrapper),'utf8').split('\n')[1],`# mosaic-cli wrapper, instance ${x.name} (row 190)`);
+ });
+
+ await t.test('T-I4 a Console port another installed Console takes refuses port-claimed, and a named instance keeps off the default ports',async(t)=>{
+  const e=await mk(t),a=await named(e,'alpha'),b=await named(e,'beta');await seed(a);
+  const held=`port ${a.port} is taken by ${join(e.units,a.con)}`,free=await freePort();
+  const install=(x,...flags)=>shOut(x.env,'webui-service.sh','install',...x.flags,'--copy',B,'--copies',COPIES,...flags,'--business','acme');
+  const unitsBefore=stamp(e.units),binBefore=stamp(e.bin);
+  for(const [label,x,flags,code,msg] of [
+   ['beta on alpha\'s port',b,['--port',a.port],1,`webui-service: refusing port-claimed: ${held}; nothing was changed\n`],
+   ['beta\'s tester port on alpha\'s port',b,['--port',free,'--tester-port',a.port],1,`webui-service: refusing port-claimed: ${held}; nothing was changed\n`],
+   ['the default on alpha\'s port',e,['--port',a.port],1,`webui-service: refusing port-claimed: ${held}; nothing was changed\n`],
+   ['beta with no --port',b,[],4,'webui-service: stack instance beta needs --port; it has no default port\n'],
+   ...['7330','7332','7333'].map((p)=>[`beta on ${p}`,b,['--port',p],4,`webui-service: port-reserved: ${p} is reserved for the default instance (7330 7332 7333)\n`]),
+   ['beta\'s tester port on 7333',b,['--port',free,'--tester-port','7333'],4,'webui-service: port-reserved: 7333 is reserved for the default instance (7330 7332 7333)\n'],
+  ]){
+   const r=install(x,...flags);assert.equal(r.status,code,`${label}: ${r.stderr}`);assert.equal(r.stderr,msg,label);
+   assert.deepEqual(stamp(e.units),unitsBefore,label);assert.deepEqual(stamp(e.bin),binBefore,label);
+  }
+  // beta on its own port passes: the seed installs both its units and adopts.
+  await seed(b);assert.ok(existsSync(join(e.units,b.con)));
+  // stack-release: a target Console port another Console takes refuses before anything stops.
+  const refused=async(label,...args)=>{
+   const before=fp(b),n=calls(e).length,logs=logLines(b).length;
+   const r=await run(b,'activate',C1,'acme',...args);assert.equal(r.code,3,`${label}: ${r.err}`);
+   assert.equal(r.err,`stack-release: refusing port-claimed: ${held}\n`,label);
+   assert.deepEqual(fp(b),before,label);assert.deepEqual(startsStops(e,n),[],label);
+   assert.equal(logLines(b).length,logs+1,label);assert.deepEqual([logLines(b).at(-1).result,logLines(b).at(-1).code],['refused','port-claimed'],label);
+  };
+  await refused('--tester-port','--tester-port',a.port);
+  const p=pointer(b);p.console[1]=a.port;writeFileSync(b.pointer,JSON.stringify(p)+'\n');
+  await refused('the pointer\'s --port');
+  const plan=await run(b,'activate',C1,'acme','--plan');assert.equal(plan.code,3,plan.err);
+  assert.ok(plan.out.split('\n').includes(`refuses port-claimed: ${held}`),plan.out);
+ });
+
+ // T-I6: activate and rollback on x leave y's every file, directory and the shared prefix drop-in
+ // directories as they were, and open nothing of y's config dir or data root.
+ const noCrossReach=async(t,xn,yn)=>{
+  const e=await mk(t),x=await named(e,xn),y=await named(e,yn);
+  for(const d of [...SHARED_DROPINS,`${x.tmpl}.d`,`${x.con}.d`,`${y.tmpl}.d`,`${y.con}.d`]){mkdirSync(join(e.units,d));writeFileSync(join(e.units,d,'t-i6.conf'),`# row 190 T-I6: ${d}\n`)}
+  await seed(x);await seed(y);
+  const mine=()=>stamp(dirname(y.cfg),y.data,...[y.tmpl,y.con,`${y.tmpl}.d`,`${y.con}.d`,...SHARED_DROPINS].map((u)=>join(e.units,u)),join(e.bin,y.wrapper),join(e.bin,'mosaic'));
+  const before=mine(),n=calls(e).length;
+  const watched=[...dirsUnder(dirname(y.cfg)),...dirsUnder(y.data)];
+  for(const d of [dirname(y.cfg),y.data,join(y.data,'bus'),y.state])assert.ok(watched.includes(d),d);
+  for(const d of watched)await watchDir(e,d);
+  const act=await run(x,'activate',C1,'acme');assert.equal(act.code,0,act.out+act.err);
+  const back=await run(x,'rollback','acme');assert.equal(back.code,0,back.out+back.err);
+  assert.deepEqual((await Promise.all(e.watches.map((s)=>s()))).filter(([,c])=>c!==0),[],`${xn}'s runs opened ${yn}'s files`);
+  assert.deepEqual(mine(),before);
+  assert.deepEqual(calls(e).slice(n).filter((c)=>c.includes(yn)),[]);
+  const sets=readdirSync(join(x.state,'stack-rollback')).sort();assert.equal(sets.length,2,sets.join(' '));
+  for(const s of sets){
+   const rs=join(x.state,'stack-rollback',s);
+   assert.deepEqual(readdirSync(rs).sort(),[x.tmpl,`${x.tmpl}.d`,x.con,`${x.con}.d`,'wrapper','WRAPPER_MODE',`show-${x.bus}.txt`,`show-${x.con}.txt`,'SHA256SUMS','steps.log'].sort(),s);
+   assert.equal(readFileSync(join(rs,'wrapper'),'utf8').split('\n')[1],`# mosaic-cli wrapper, instance ${xn} (row 190)`);
+  }
+  assert.equal(pointer(x).copy,B);assert.equal(pointer(y).copy,B);
+ };
+ await t.test('T-I6 alpha\'s activate and rollback reach nothing of beta\'s',(t)=>noCrossReach(t,'alpha','beta'));
+ await t.test('T-I6 swapped: beta\'s reach nothing of alpha\'s',(t)=>noCrossReach(t,'beta','alpha'));
+
+ await t.test('T-I7 MOSAIC_CONFIG naming alpha\'s config with no flag refuses instance-root-mismatch and changes nothing',async(t)=>{
+  const e=await mk(t),a=await named(e,'alpha');await seed(a);
+  const x={...a,env:{...a.env,MOSAIC_CONFIG:a.cfg},flags:[]};
+  const before=fp(a),n=calls(e).length,logs=logLines(a).length,unitsBefore=stamp(e.units),binBefore=stamp(e.bin);
+  const r=await run(x,'activate',C1,'acme');assert.equal(r.code,3,r.err);assert.match(r.err,/instance-root-mismatch/);assert.equal(r.out,'');
+  const i=shOut(x.env,'bus-service.sh','install','--copy',C1,'--copies',COPIES,'--claude',e.claude);
+  assert.equal(i.status,3,i.stderr);assert.match(i.stderr,/instance-root-mismatch/);
+  assert.deepEqual(calls(e).slice(n),[]);assert.deepEqual(fp(a),before);assert.equal(logLines(a).length,logs);
+  assert.deepEqual(stamp(e.units),unitsBefore);assert.deepEqual(stamp(e.bin),binBefore);
+ });
+
+ await t.test('T-I9 another instance\'s bus active refuses nothing; one of this instance\'s does',async(t)=>{
+  const e=await mk(t);await seed(e);
+  const a=await named(e,'alpha'),b=await named(e,'beta');await seed(a);await seed(b);
+  for(const x of [e,b]){const r=await run(x,'activate',C1,'acme');assert.equal(r.code,0,`${x.name??'default'}: ${r.out+r.err}`)}
+  const setUnit=(u,state)=>{const s=units(e);if(state)s[u]={...(s[u]||{pid:null,wd:''}),state};else delete s[u];writeFileSync(join(e.sd,'units.json'),JSON.stringify(s))};
+  for(const [u,state,msg] of [['[email protected]','active','[email protected] is active; the copy and wrapper switch reach it too'],[a.bus,'activating',`${a.bus} is activating`]]){
+   const was=units(e)[u];setUnit(u,state);
+   const before=fp(a),n=calls(e).length;
+   const r=await run(a,'activate',C1,'acme');assert.equal(r.code,3,r.err);
+   assert.equal(r.err,`stack-release: refusing instance-busy: ${msg}\n`);assert.deepEqual(fp(a),before);assert.deepEqual(startsStops(e,n),[]);
+   setUnit(u,was&&was.state);if(was){const s=units(e);s[u]=was;writeFileSync(join(e.sd,'units.json'),JSON.stringify(s))}
+  }
+  const r=await run(a,'activate',C1,'acme');assert.equal(r.code,0,r.out+r.err);
+ });
+});
@@ -4,8 +4,9 @@
 // every session path are constructor arguments, with no default. At
 // construction and again at bind, their real paths must lie inside the
 // explicit fixture root and outside every protected location: the
-// repository's .pi/state/, ~/.pi, ~/.claude, the configured data root and any
-// path a seat registration names. A path is refused when it is inside a
+// repository's .pi/state/, ~/.pi, ~/.claude, the configured data root, every
+// stack instance's config dir and data roots (row 190) and any path a seat
+// registration names. A path is refused when it is inside a
 // protected location or contains one. The real protections always apply;
 // options only add to them, so a test can't switch them off.
 //
@@ -44,9 +45,9 @@ export function realPath(p) {
 const inside = (child, parent) => child === parent || child.startsWith(parent.endsWith(sep) ? parent : parent + sep);
 const overlaps = (a, b) => inside(a, b) || inside(b, a);

-function configuredDataRoot(home) {
+function configuredDataRoot(home, name = "dev") {
  try {
-    const cfg = JSON.parse(readFileSync(join(home, ".config", "mosaic-dev", "config.json"), "utf8"));
+    const cfg = JSON.parse(readFileSync(join(home, ".config", `mosaic-${name}`, "config.json"), "utf8"));
    if (typeof cfg?.dataRoot === "string" && cfg.dataRoot) return cfg.dataRoot.replace(/^~(?=$|\/)/, home);
  } catch {
    // An unreadable config adds no location; the default data root still applies.
@@ -54,6 +55,21 @@ function configuredDataRoot(home) {
  return null;
 }

+// Row 190: the stack instances in `home`, one per ~/.config/mosaic-NAME whose
+// NAME passes the instance name rule (scripts/mosaic-config.mjs), so
+// ~/.config/mosaic.bak adds nothing. Only the names are read here.
+const INSTANCE_NAME = /^[a-z][a-z0-9]{1,15}$/;
+function instanceNames(home) {
+  try {
+    return readdirSync(join(home, ".config"))
+      .filter((entry) => entry.startsWith("mosaic-") && INSTANCE_NAME.test(entry.slice("mosaic-".length)))
+      .map((entry) => entry.slice("mosaic-".length))
+      .sort();
+  } catch {
+    return [];
+  }
+}
+
 // Registrations under <dataRoot>/seats/<layout>/<seat>/registration.json. An
 // unreadable one adds nothing; the data root itself is protected anyway.
 function registrationsUnder(dataRoot) {
@@ -111,6 +127,14 @@ export class LiveSessionGuard {
      protectedPaths.push({ path: join(h, ".mosaic-dev"), why: "the default data root" });
      const configured = configuredDataRoot(h);
      if (configured) protectedPaths.push({ path: configured, why: "the configured data root" });
+      // Each instance's config dir and ~/.mosaic-NAME whatever its config
+      // says, so a broken config can't drop them, then its config's dataRoot.
+      for (const name of instanceNames(h)) {
+        protectedPaths.push({ path: join(h, ".config", `mosaic-${name}`), why: `stack instance ${name}'s config dir` });
+        protectedPaths.push({ path: join(h, `.mosaic-${name}`), why: `stack instance ${name}'s default data root` });
+        const root = configuredDataRoot(h, name);
+        if (root) protectedPaths.push({ path: root, why: `stack instance ${name}'s configured data root` });
+      }
    }
    for (const d of dataRoots) protectedPaths.push({ path: d, why: "the data root" });
    const roots = protectedPaths.filter((p) => p.why.includes("data root")).map((p) => p.path);
@@ -133,6 +133,12 @@ the copy, and retains the unit's restart, brake and stop behavior. Without
 pinning. Status reads effective WorkingDirectory, including drop-ins, and
 prints the tree and copy id or checkout path.

+`--instance NAME` (row 190, any verb) renders `[email protected]`,
+which sets `Environment=MOSAIC_CONFIG=` to NAME's config, and status reads
+that config. Uninstall's active check covers only `mosaic-discord-NAME@*`.
+Without the flag the unit is as before. See
+[TOOLS.md, Stack instances](../../docs/TOOLS.md#stack-instances---instance-name-row-190).
+
 Every live step requires Mos's go after the SetSpark freeze lifts. Re-pin:
 make the new pushed copy with stack-copy.sh; run
 `node <copy>/packages/discord/src/cli.mjs check <binding> --repo <copy> --offline`;
@@ -14,6 +14,7 @@ StartLimitBurst=5
 Type=simple
 WorkingDirectory=@REPO@
 Environment=PATH=@PATH@
+@CONFIG_ENV@
 # A supervised run first clears a lock left by a crash or a reboot, and
 # refuses with exit 3 while STOP is present or the binding is held. Exit 3
 # is never retried: the brake belongs to the operator. This happens inside
@@ -14,7 +14,8 @@ test('pinned Discord render/install and missing prerequisites; checkout bytes un
 for(const line of r.stdout.split('\n').filter(l=>/^(ExecStart|WorkingDirectory)=/.test(l)))assert.ok(!line.includes(ROOT),line);
 const legacy=s.run(['render']);assert.equal(legacy.status,0,legacy.stderr);
 const nodeDir=dirname(process.execPath),originalPath='/usr/local/bin:/usr/bin:/bin',path=originalPath.split(':').includes(nodeDir)?originalPath:nodeDir+':'+originalPath;
- const expected=readFileSync(join(ROOT,'packages/discord/systemd/[email protected]'),'utf8').replaceAll('@REPO@',ROOT).replaceAll('@PATH@',path);assert.equal(legacy.stdout,expected);
+ // Row 190: the default instance deletes the @CONFIG_ENV@ line.
+ const expected=readFileSync(join(ROOT,'packages/discord/systemd/[email protected]'),'utf8').replace('@CONFIG_ENV@\n','').replaceAll('@REPO@',ROOT).replaceAll('@PATH@',path);assert.equal(legacy.stdout,expected);
 assert.equal(r.stdout.split('\n').filter(l=>!/^(ExecStart|WorkingDirectory)=/.test(l)).join('\n'),legacy.stdout.split('\n').filter(l=>!/^(ExecStart|WorkingDirectory)=/.test(l)).join('\n'));
 const installed=s.run(['install',...args,'--dir',s.units,'--no-reload']);assert.equal(installed.status,0,installed.stderr);assert.equal(readFileSync(join(s.units,'[email protected]'),'utf8'),r.stdout);
 for(const id of ['','short','b'.repeat(40)])assert.equal(s.run(['install','--copy',id,'--copies',s.copies,'--dir',join(s.root,'missing'),'--no-reload']).status,1);
@@ -122,6 +122,16 @@ allow-user must be the 64-character Authentik uid (decision 101). Status
 names the copy and refactor drift. Files and directories are read-only;
 copies are retained. Existing Console-only copies are not migrated or pruned.

+With `--instance NAME` (row 190) every verb works on
+`mosaic-webui-NAME.service`, which sets NAME's `MOSAIC_CONFIG`; install
+checks NAME's `mosaic-bus-NAME@` units for the copy. render and install then
+need `--port`, and 7330, 7332 or 7333 as `--port` or `--tester-port` exits 4
+with port-reserved. For every instance, install refuses a `--port` or
+`--tester-port` that another installed Console unit in the unit directory
+already takes. That refusal is port-claimed, exit 1, and writes nothing. A
+unit with no `--port` holds 7332. See
+[TOOLS.md, Stack instances](../../docs/TOOLS.md#stack-instances---instance-name-row-190).
+
 The single update and rollback sequence is
 [TOOLS.md, Pinned stack update](../../docs/TOOLS.md#pinned-stack-update).
 A bus restart ends managed sessions, so no PM turn may be in flight.
@@ -129,6 +139,45 @@ Switching the Console, bus or wrapper, changing any unit, and starting or
 stopping either service requires Mos's go for that live step. Agents build
 and test fixtures; they stop before the live sequence.

+## Sign-in in the Console (Q175 phase 1, #1690)
+
+`serve --sso [--send] [--tester-port N]` makes the Console an OpenID Connect
+relying party. It reads `console.sso` from the system config (`publicOrigin`
+and one or more providers, each with its issuer, client id, a client secret
+slot, the signing algorithms it accepts and the subjects allowed in). The
+design is `agents/sage/work/q175-sso/DESIGN.md`. `--sso` can't be combined
+with `--public-host`, `--auth-header`, `--allow-user` or `--proof-*`; `--send`
+takes `--sso` in place of the preview set.
+
+- The client secret is read once at start from
+  `<config dir>/secrets/mosaic-stack/<slot>`. The start refuses a slot that is
+  a symbolic link, not a regular file, owned by another user, has any group or
+  other mode bit, or sits in the repository, the `--checkout` directory or a
+  stack copy. The value is never printed.
+- At start the Console fetches each provider's discovery document and JWKS. A
+  provider that can't be reached (a network error, a timeout, a status other
+  than 200, or a body that isn't JSON) leaves the Console up with that
+  provider's `/auth/login` at 503 and a retry every 5 s, doubling, capped at 5
+  minutes. A document that fails a check (issuer, algorithms, S256, a usable
+  key) refuses the start. `/healthz` adds `sso: { <id>: "ready" | "unreachable"
+  | "refused" }`.
+- The Console listener serves only the Host of `publicOrigin`, whatever port
+  it listens on. Any other Host, a loopback one included, gets 403 `public
+  Host required`, except `GET /healthz`, which stays open on loopback for the
+  status and release gates. The loopback operator path in the preview section
+  above does not exist under `--sso`.
+- Without a session, `/api/*` gets 401 `sign-in required` and a page load gets
+  a 303 to `/auth/login?return=<path>`. The page then shows the signed-out line
+  with a link back to sign-in. A session lasts at most 8 hours and ends after 1
+  hour without a page load or a write; a restart ends every session.
+- The page shows Sign out only under `--sso`. It posts to `/auth/logout`, which
+  ends the session and goes to the provider's end-session endpoint when it has
+  one, or to `/auth/signed-out`.
+- With `--tester-port`, the tester listener refuses any request carrying an
+  `Authorization` header, a `__Host-mosaic_session` or `__Host-mosaic_login`
+  cookie, or an `x-authentik-*` header (403 `tester listener takes no
+  sign-in`). It never serves `/auth/*`.
+
 ## Message a role (row 76, #1570)

 ```sh
@@ -58,8 +58,9 @@ export async function chatHTTP(req, res, { path, search, chat, named, send, prev
      if (one(req, 'origin') !== preview.origin) return refuse(403, 'cross-origin');
    } else {
      if (!send || !named || !preview) return refuse(403, 'read-only');
-      if (one(req, preview.header) !== preview.user) return refuse(401, 'unauthenticated');
-      if (one(req, 'origin') !== `https://${preview.host}`) return refuse(403, 'cross-origin');
+      // Q175 phase 1 (#1690): under --sso the session was checked before this route.
+      if (preview.sso !== true && one(req, preview.header) !== preview.user) return refuse(401, 'unauthenticated');
+      if (one(req, 'origin') !== (preview.origin ?? `https://${preview.host}`)) return refuse(403, 'cross-origin');
    }
    if (one(req, 'sec-fetch-site') !== 'same-origin') return refuse(403, 'cross-site');
  }
@@ -7,20 +7,23 @@ import { views } from '../../bus/src/views.mjs';
 import { loadSystem, socketPath, REPO, rolesDir } from '../../cli/src/config.mjs';
 import { configDir } from '../../business/src/business.mjs';
 import { consoleReads, redactor } from './reads.mjs';
+import { createSso, readSlot } from './sso.mjs';
 import { statSync } from 'node:fs';
 import { isAbsolute } from 'node:path';
 import { ID_PATTERN } from '../../business/src/vocabulary.mjs';
 const args = process.argv.slice(2);
-const usage = 'node packages/webui/src/cli.mjs serve [--port N] [--tester-port N] [--checkout PATH] [--board http://127.0.0.1:7331] [--business ID] [--public-host NAME --auth-header HEADER --allow-user ID [--send] [--proof-header NAME --proof-file PATH]]';
+const usage = 'node packages/webui/src/cli.mjs serve [--port N] [--tester-port N] [--checkout PATH] [--board http://127.0.0.1:7331] [--business ID] [--sso [--send]] [--public-host NAME --auth-header HEADER --allow-user ID [--send] [--proof-header NAME --proof-file PATH]]';
 try {
  if (args.length === 1 && ['--help', '-h'].includes(args[0])) { console.log(usage); process.exit(0); }
  if (args.shift() !== 'serve') throw new Error(usage);
  const options = { board: DEFAULT_BOARD, port: 7330 }, preview = {}, proofFlags = {};
-  let sendOn = false, testerPort = null;
+  let sendOn = false, ssoOn = false, testerPort = null;
  while (args.length) {
    const flag = args.shift();
    // Row 76 (#1570): the one flag without a value.
    if (flag === '--send') { sendOn = true; continue; }
+    // Q175 phase 1 (#1690): the Console signs people in itself, from console.sso in config.json.
+    if (flag === '--sso') { ssoOn = true; continue; }
    const value = args.shift();
    if (!value) throw new Error(`missing value for ${flag}`);
    if (flag === '--port') {
@@ -51,9 +54,10 @@ try {
    else throw new Error(`unknown option: ${flag}`);
  }
  if (testerPort !== null && (testerPort === options.port || testerPort === 7332)) throw new Error('--tester-port must differ from --port and cannot be the forwarded port 7332');
+  if (ssoOn && (Object.keys(preview).length || Object.keys(proofFlags).length)) throw new Error('--sso cannot be combined with --public-host, --auth-header, --allow-user or --proof-*');
  options.preview = previewOptions(preview);
  const proof = proofOptions(proofFlags, options.preview);
-  if (sendOn && !options.preview) throw new Error('--send needs the preview mode (--public-host, --auth-header and --allow-user)');
+  if (sendOn && !options.preview && !ssoOn) throw new Error('--send needs the preview mode (--public-host, --auth-header and --allow-user) or --sso');
  // The bus views (slice 1 S5) need the system config. Without it the
  // board still serves and the bus routes answer not-configured.
  // The Queue, Business and Settings reads (row 54) need no bus; without
@@ -77,31 +81,46 @@ try {
    busLine = `Bus: ${options.business ?? 'the running bus host\'s business'}`;
  } catch (err) {
    const why = redactor({ configDir: configDir() })(err.message);
+    if (ssoOn) throw new Error(`--sso needs the system config (${why})`);
    if (sendOn) throw new Error(`--send needs the bus configured (${why})`);
    if (testerPort !== null) throw new Error(`--tester-port needs the bus configured (${why})`);
    busLine = `Bus: not configured (${why})`;
  }
  const reads = consoleReads({ root: REPO, queueRoot: options.checkout ?? REPO, system, configDir: configDir(), rolesDir: rolesDir(), business: options.business ?? null });
-  const server = await startServer({ board: options.board, port: options.port, bus, reads, preview: options.preview, proof, send, settingsWrite, projectFiles, projectFile, projectSave, chat, nameWrite, assistantStop, instancesWrite, routesWrite });
+  // The sign-in config is checked again here, then each slot file, before anything listens. A
+  // provider that can't be reached starts degraded; one whose discovery is refused stops the start.
+  let sso = null;
+  if (ssoOn) {
+    if (!system.console?.sso) throw new Error('--sso needs console.sso in the system config');
+    const secrets = new Map(system.console.sso.providers.map(p => [p.id, readSlot(configDir(), p, { repo: REPO, checkout: options.checkout ?? null })]));
+    sso = await createSso(system.console.sso, { secrets });
+  }
+  let server;
+  try {
+    server = await startServer({ board: options.board, port: options.port, bus, reads, preview: options.preview, sso, proof, send, settingsWrite, projectFiles, projectFile, projectSave, chat, nameWrite, assistantStop, instancesWrite, routesWrite });
+  } catch (err) { sso?.close(); throw err; }
  let testerServer = null;
  if (testerPort !== null) {
    const call = busCaller({ dataRoot: system.dataRoot, socket: socketPath(system.dataRoot), business: options.business ?? null, cli: TESTER_CLI });
    const testerBus = { ...views({ call }), names: () => call('names'), instances: () => call('instances'), routes: () => call('routes') };
    try {
      testerServer = await startServer({ host: '127.0.0.1', port: testerPort, board: options.board,
-        tester: true, testerProofHeader: proof?.header ?? null, testerAuthHeader: options.preview?.header ?? null, bus: testerBus, reads,
+        tester: true, testerNoSignIn: ssoOn, testerProofHeader: proof?.header ?? null, testerAuthHeader: options.preview?.header ?? null, bus: testerBus, reads,
        projectFiles: args => call('project.files', args), projectFile: args => call('project.file', args),
        instancesWrite: args => call('instances.set', args), routesWrite: args => call('routes.set', args), nameWrite: args => call('name.set', args),
        // Row 177 (#1675): the tester's own chat, through the tester CLI; 7332's stays the human's.
        chat: createChat({ call }),
      });
-    } catch (err) { await new Promise(resolve => server.close(resolve)); throw err; }
+    } catch (err) { sso?.close(); await new Promise(resolve => server.close(resolve)); throw err; }
  }
  const previewLine = options.preview ? `\nPreview: https://${options.preview.host}/ through the proxy, signed-in user from ${options.preview.header}, ${send ? 'reads and human messages to roles (--send); one line per send below' : 'read-only'}` : '';
  const proofLine = `\nProxy: proxy proof ${proof ? 'on' : 'off'}`;
+  // One line per provider: id, issuer, subject count and state. No client id, secret or sub.
+  const health = sso?.health() ?? {};
+  const ssoLines = sso ? `\nSign-in: ${sso.publicOrigin}/ (--sso), ${send ? 'reads and human writes (--send)' : 'read-only'}` + sso.summary().map(p => `\nSign-in provider: ${p.id} issuer ${p.issuer} subjects ${p.subjects} (${health[p.id]})`).join('') : '';
  const queueLine = options.checkout ? '\nQueue: read from the --checkout directory' : '';
-  console.log(`Mosaic Console: http://127.0.0.1:${server.address().port}/\nBoard: ${options.board}\n${busLine}${queueLine}${previewLine}${proofLine}${testerServer ? `\nTester Console: http://127.0.0.1:${testerServer.address().port}/ (binds the tester)` : ''}\nCtrl-C stops this server.`);
-  for (const signal of ['SIGINT', 'SIGTERM']) process.once(signal, () => { server.close(); testerServer?.close(); });
+  console.log(`Mosaic Console: http://127.0.0.1:${server.address().port}/\nBoard: ${options.board}\n${busLine}${queueLine}${previewLine}${ssoLines}${proofLine}${testerServer ? `\nTester Console: http://127.0.0.1:${testerServer.address().port}/ (binds the tester)` : ''}\nCtrl-C stops this server.`);
+  for (const signal of ['SIGINT', 'SIGTERM']) process.once(signal, () => { sso?.close(); server.close(); testerServer?.close(); });
 } catch (err) {
  console.error(`refused: ${err.message}`);
  process.exitCode = 2;
@@ -16,6 +16,11 @@
  // The first one sets body.signed-out (the listener below); after that no Console fetch is made.
  const out = () => document.body.classList.contains('signed-out');
  const signOut = () => { if (!out()) document.dispatchEvent(new Event('mosaic-signed-out')); };
+  // Q175 phase 1 (#1690): under --sso the Console itself answers a read without a session with 401
+  // `sign-in required`; that signs the page out too, and the line links to the Console's sign-in.
+  // Any other 401 stays an error. `sso` comes from /api/config.
+  let sso = false;
+  const signInRequired = (res, body) => res.status === 401 && body?.error === 'sign-in required';
  const signedOut = () => Object.assign(new Error('the sign-in proxy redirected it, so it never reached the Console'), { signedOut: true });
  const labels = { registration: 'registered', 'first-user-message': 'first message', 'tmux-pane': 'tmux pane', 'session-cwd': 'session cwd', 'workspace-git-root': 'git root' };
  const source = value => value ? `<span class="source">${esc(labels[value] || value)}</span>` : '';
@@ -110,6 +115,7 @@
    const res = await fetch(path, { cache: 'no-store', redirect: 'manual' });
    if (res.type === 'opaqueredirect') { signOut(); throw signedOut(); }
    let body; try { body = await res.json(); } catch { body = { error: `HTTP ${res.status}` }; }
+    if (signInRequired(res, body)) { sso = true; signOut(); throw signedOut(); }
    return { ok: res.ok, body };
  }
  function blockNode(b) {
@@ -304,6 +310,7 @@
    const res = await fetch(path, value === undefined ? { cache: 'no-store', redirect: 'manual' } : { method: 'POST', headers: { 'content-type': 'application/json' }, body: JSON.stringify(value), redirect: 'manual' });
    if (res.type === 'opaqueredirect') { signOut(); throw signedOut(); }
    const result = await res.json();
+    if (signInRequired(res, result)) { sso = true; signOut(); throw signedOut(); }
    if (!res.ok) throw Object.assign(new Error(result.error || `HTTP ${res.status}`), { status: res.status });
    return result;
  }
@@ -452,7 +459,7 @@
  });
  // Signed out: everything drawn from a Console read goes, because none of it can be refreshed. The
  // line says so once; the send form (bus.js) keeps its draft and receipt. Reload is the way back.
-  document.addEventListener('mosaic-signed-out', () => {
+  document.addEventListener('mosaic-signed-out', e => {
    if (out()) return;
    document.body.classList.add('signed-out');
    clearTimeout(timer); convGen++;
@@ -461,9 +468,13 @@
    for (const id of ['projects', 'waiting', 'seen', 'sessions']) $(id).replaceChildren();
    $('refresh').disabled = $('pause').disabled = true;
    const line = $('signed-out');
-    line.innerHTML = '<p><b>Signed out.</b> Reload the page to sign in.</p>'; line.hidden = false;
+    line.innerHTML = sso || e.detail?.signIn
+      ? `<p><b>Signed out.</b> <a href="/auth/login?${esc(new URLSearchParams({ return: location.pathname + location.search }))}">Sign in again</a>.</p>`
+      : '<p><b>Signed out.</b> Reload the page to sign in.</p>';
+    line.hidden = false; $('sign-out').hidden = true;
    // Focus moves to the line only if what had it is gone or disabled, never out of a form being typed in.
    setTimeout(() => { const a = document.activeElement; if (!a || a === document.body || a.disabled || !a.getClientRects().length) line.focus(); });
  });
-  api('/api/config').then(config => { board = config.board; $('board-url').textContent = `Board: ${board}`; }).catch(err => { if (machine) error(err); }).finally(refresh);
+  // Sign out (sage-1347, F7): a plain same-origin form POST to /auth/logout, shown only under --sso.
+  api('/api/config').then(config => { board = config.board; $('board-url').textContent = `Board: ${board}`; if (config.sso === true) { sso = true; $('sign-out').hidden = out(); } }).catch(err => { if (machine) error(err); }).finally(refresh);
 })();
@@ -30,6 +30,10 @@
  const out = () => document.body.classList.contains('signed-out');
  const signOut = () => { if (!out()) document.dispatchEvent(new Event('mosaic-signed-out')); };
  const signedOut = () => new ReadError('signed-out', 'The sign-in proxy redirected the read.', 0);
+  // Q175 phase 1 (#1690, sage-1340 F1): under --sso a read without a session gets 401 `sign-in
+  // required` from the Console itself. That signs out the same way; any other 401 stays an error.
+  const signInRequired = (res, body) => res.status === 401 && body?.error === 'sign-in required';
+  const signOutSso = () => { if (!out()) document.dispatchEvent(new CustomEvent('mosaic-signed-out', { detail: { signIn: true } })); };
  // `replies` takes a message id as `id`; trail takes `subject`.
  async function fetchRead(verb, subject) {
    if (out()) throw signedOut();
@@ -38,6 +42,7 @@
    catch { throw new ReadError('unreachable', 'The Console server did not answer.', 0); }
    if (res.type === 'opaqueredirect') { signOut(); throw signedOut(); }
    try { body = await res.json(); } catch { throw new ReadError('unreachable', 'The Console server did not answer.', 0); }
+    if (signInRequired(res, body)) { signOutSso(); throw signedOut(); }
    if (!res.ok || !body || !Array.isArray(body.rows)) throw new ReadError(typeof body?.error === 'string' ? body.error : 'invalid-response', typeof body?.message === 'string' ? body.message : `HTTP ${res.status}`, res.status);
    return { ...body, rows: body.rows, at: body.at };
  }
@@ -50,6 +55,7 @@
    try { res = await fetch(`/api/${path}`, { cache: 'no-store', redirect: 'manual' }); } catch { throw unreachable(); }
    if (res.type === 'opaqueredirect') { signOut(); throw signedOut(); }
    try { body = await res.json(); } catch { throw unreachable(); }
+    if (signInRequired(res, body)) { signOutSso(); throw signedOut(); }
    if (!res.ok || !body || typeof body !== 'object' || Array.isArray(body)) throw Object.assign(new ReadError(typeof body?.error === 'string' ? body.error : 'invalid-response', typeof body?.message === 'string' ? body.message : `HTTP ${res.status}`, res.status), { module: true });
    return body;
  }
@@ -9,7 +9,7 @@
 <header class="cmdbar"><a href="/" class="wordmark"><svg class="mark" viewBox="0 0 16 17" aria-hidden="true"><use href="/icons.svg#mark"/></svg>Mosaic<small>Console</small></a>
 <button type="button" class="cmdk" id="cmdk" aria-haspopup="dialog" aria-controls="cmdk-dialog"><svg class="i" aria-hidden="true"><use href="/icons.svg#i-search"/></svg><span>Go to a view, decision or task</span><kbd>Ctrl K</kbd></button>
 <p class="fresh" id="fresh"><span id="fresh-board"></span><span id="fresh-bus"></span></p>
-<div class="cmd-right"><label>Palette<select id="palette"></select></label><label>Appearance<select id="mode"><option value="system">system</option><option value="light">light</option><option value="dim">dim</option><option value="dark">dark</option></select></label><button class="btn" id="refresh" type="button">Refresh</button><button class="btn" id="pause" type="button" aria-pressed="false">Pause</button></div></header>
+<div class="cmd-right"><label>Palette<select id="palette"></select></label><label>Appearance<select id="mode"><option value="system">system</option><option value="light">light</option><option value="dim">dim</option><option value="dark">dark</option></select></label><button class="btn" id="refresh" type="button">Refresh</button><button class="btn" id="pause" type="button" aria-pressed="false">Pause</button><form id="sign-out" method="post" action="/auth/logout" hidden><button class="btn" type="submit">Sign out</button></form></div></header>
 <div class="frame">
 <nav class="tree" aria-label="Console"><h2 class="tree-title">Console</h2><ul class="s1-sections" id="sections"></ul><div id="board-tree"><h2 class="tree-title">Projects</h2><div id="projects"><p class="muted">Loading projects…</p></div><p class="small muted">Select a project to filter sessions. Waiting on you always shows all projects.</p></div></nav>
 <main id="main" class="content" tabindex="-1"><div id="signed-out" class="banner ref" role="alert" tabindex="-1" hidden></div><div id="bus-down" class="banner err" role="alert" hidden></div><div class="page-head" id="board-head"><div><h1>Control board</h1><p id="status" class="small muted" role="status">Loading board…</p></div><div class="filters"><label><input id="show-machine" type="checkbox">Show machine sessions</label></div></div>
@@ -61,6 +61,8 @@ async function body(req, max = 4096) {
 // Row 65 (mos-0840) adds `routes`: each instance's harness, model, thinking and fallback.
 const BUS_VERBS = ['inbox', 'tasks', 'agents', 'trail', 'decisions', 'credentials', 'replies', 'messages', 'usage', 'limits', 'names', 'instances', 'routes'];
 const DECISION_LISTS = ['roles', 'recent'];
+// Q175 phase 1 (#1690, F8): either sign-in cookie, which the tester listener refuses under --sso.
+const SIGN_IN_COOKIE = /(?:^|;)\s*__host-mosaic_(?:session|login)\s*=/i;
 // Row 177 (#1675): the chat writes the tester listener lets through, exactly the four chatHTTP routes.
 const TESTER_CHAT_WRITE = /^\/api\/chat\/(?:projects|threads|threads\/[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}\/(?:messages|open))$/i;
 async function busRead(res, bus, verb, search) {
@@ -160,14 +162,18 @@ async function busRead(res, bus, verb, search) {
 // broker's to refuse. Nothing retries; an outcome the bus can't confirm is reported as unknown.
 const SEND_KEYS = ['to', 'body', 'in_reply_to'];
 const one = (req, name) => (req.headersDistinct[name]?.length === 1 ? req.headersDistinct[name][0] : null);
+// Q175 phase 1 (#1690): under --sso the writer comes from a session the handler already checked,
+// so it carries `sso: true` and the public origin; the preview writer still checks its header.
+const signedIn = (req, p) => p.sso === true || one(req, p.header) === p.user;
+const ownOrigin = p => p.origin ?? `https://${p.host}`;
 async function busSend(req, res, { send, preview, log }) {
-  if (one(req, preview.header) !== preview.user) return json(res, 401, { error: 'sign-in required' });
+  if (!signedIn(req, preview)) return json(res, 401, { error: 'sign-in required' });
  let to = null;
  // `to` is quoted and cut short so a crafted value can't forge a log line.
  const line = outcome => log(`${new Date().toISOString()} send user=${JSON.stringify(preview.user)} to=${typeof to === 'string' ? JSON.stringify(to.slice(0, 64)) : 'none'} ${outcome}`);
  // `sent` tells the page which it was: false, nothing was written; 'unknown', it may have been.
  const refuse = (status, error, message, sent = false) => { line(`error=${error}`); return json(res, status, { error, message, sent }); };
-  if (one(req, 'origin') !== `https://${preview.host}`) return refuse(403, 'cross-origin request refused', 'a send needs the Console\'s own Origin');
+  if (one(req, 'origin') !== ownOrigin(preview)) return refuse(403, 'cross-origin request refused', 'a send needs the Console\'s own Origin');
  if (one(req, 'sec-fetch-site') !== 'same-origin') return refuse(403, 'cross-site request refused', 'a send needs Sec-Fetch-Site: same-origin');
  let value;
  try { value = JSON.parse((await body(req, 16384)).toString('utf8')); } catch (err) { return refuse(400, 'invalid-request', err.message); }
@@ -241,10 +247,10 @@ export function proofOptions({ proofHeader, proofFile } = {}, preview = null) {
 // REQ-WEB-1: same signed-in send boundary, a distinct strict settings payload.
 async function settingsSend(req, res, { settingsWrite, preview, log }) {
  const refuse = (status, error, message) => json(res, status, { error, message, sent: false });
-  if (one(req, preview.header) !== preview.user) {
+  if (!signedIn(req, preview)) {
    return refuse(401, 'sign-in required', 'sign in again');
  }
-  if (one(req, 'origin') !== `https://${preview.host}`) {
+  if (one(req, 'origin') !== ownOrigin(preview)) {
    return refuse(403, 'cross-origin request refused', 'settings need the Console origin');
  }
  if (one(req, 'sec-fetch-site') !== 'same-origin') {
@@ -292,8 +298,8 @@ async function seatSend(req, res, { route, write, preview, log }) {
  // The instance is quoted and cut short so a crafted value can't forge a log line.
  const line = outcome => log(`${new Date().toISOString()} ${route.kind} user=${JSON.stringify(preview.user)} instance=${quoted(instance)} ${outcome}`);
  const refuse = (status, error, message, sent = false) => { line(`error=${error}`); return json(res, status, { error, message, sent }); };
-  if (!preview.tester && one(req, preview.header) !== preview.user) return json(res, 401, { error: 'sign-in required', message: 'sign in again', sent: false });
-  if (one(req, 'origin') !== (preview.origin ?? `https://${preview.host}`)) return refuse(403, 'cross-origin request refused', 'this needs the Console\'s own Origin');
+  if (!preview.tester && !signedIn(req, preview)) return json(res, 401, { error: 'sign-in required', message: 'sign in again', sent: false });
+  if (one(req, 'origin') !== ownOrigin(preview)) return refuse(403, 'cross-origin request refused', 'this needs the Console\'s own Origin');
  if (one(req, 'sec-fetch-site') !== 'same-origin') return refuse(403, 'cross-site request refused', 'this needs same-origin Fetch Metadata');
  let value;
  try { value = JSON.parse((await body(req)).toString('utf8')); } catch (err) { return refuse(400, 'invalid-request', err.message); }
@@ -335,8 +341,8 @@ async function instanceSend(req, res, { instancesWrite, preview, log }) {
  // The instance is quoted and cut short so a crafted value can't forge a log line. Vars are never logged.
  const line = outcome => log(`${new Date().toISOString()} instance user=${JSON.stringify(preview.user)} instance=${quoted(instance)} ${outcome}`);
  const refuse = (status, error, message, sent = false) => { line(`error=${error}`); return json(res, status, { error, message, sent }); };
-  if (!preview.tester && one(req, preview.header) !== preview.user) return json(res, 401, { error: 'sign-in required', message: 'sign in again', sent: false });
-  if (one(req, 'origin') !== (preview.origin ?? `https://${preview.host}`)) return refuse(403, 'cross-origin request refused', 'this needs the Console\'s own Origin');
+  if (!preview.tester && !signedIn(req, preview)) return json(res, 401, { error: 'sign-in required', message: 'sign in again', sent: false });
+  if (one(req, 'origin') !== ownOrigin(preview)) return refuse(403, 'cross-origin request refused', 'this needs the Console\'s own Origin');
  if (one(req, 'sec-fetch-site') !== 'same-origin') return refuse(403, 'cross-site request refused', 'this needs same-origin Fetch Metadata');
  let value;
  try { value = JSON.parse((await body(req, 16384)).toString('utf8')); } catch (err) { return refuse(400, 'invalid-request', err.message); }
@@ -382,8 +388,8 @@ async function routesSend(req, res, { routesWrite, preview, log }) {
  let names = [];
  const line = outcome => log(`${new Date().toISOString()} routes user=${JSON.stringify(preview.user)} instances=${quoted(names.join(','))} ${outcome}`);
  const refuse = (status, error, message, sent = false) => { line(`error=${error}`); return json(res, status, { error, message, sent }); };
-  if (!preview.tester && one(req, preview.header) !== preview.user) return json(res, 401, { error: 'sign-in required', message: 'sign in again', sent: false });
-  if (one(req, 'origin') !== (preview.origin ?? `https://${preview.host}`)) return refuse(403, 'cross-origin request refused', 'this needs the Console\'s own Origin');
+  if (!preview.tester && !signedIn(req, preview)) return json(res, 401, { error: 'sign-in required', message: 'sign in again', sent: false });
+  if (one(req, 'origin') !== ownOrigin(preview)) return refuse(403, 'cross-origin request refused', 'this needs the Console\'s own Origin');
  if (one(req, 'sec-fetch-site') !== 'same-origin') return refuse(403, 'cross-site request refused', 'this needs same-origin Fetch Metadata');
  let value;
  try { value = JSON.parse((await body(req, 16384)).toString('utf8')); } catch (err) { return refuse(400, 'invalid-request', err.message); }
@@ -420,8 +426,8 @@ async function projectFileSend(req, res, { projectSave, preview, log }) {
  const line = outcome => log(`${new Date().toISOString()} project-file user=${JSON.stringify(preview.user)} project=${quoted(target?.project)} path=${quoted(target?.path)} ${outcome}`);
  // `sent` tells the page which it was: false, nothing was written; 'unknown', it may have been.
  const refuse = (status, error, message, sent = false) => { line(`error=${error}`); return json(res, status, { error, message, sent }); };
-  if (one(req, preview.header) !== preview.user) return json(res, 401, { error: 'sign-in required', message: 'sign in again', sent: false });
-  if (one(req, 'origin') !== `https://${preview.host}`) return refuse(403, 'cross-origin request refused', 'a save needs the Console\'s own Origin');
+  if (!signedIn(req, preview)) return json(res, 401, { error: 'sign-in required', message: 'sign in again', sent: false });
+  if (one(req, 'origin') !== ownOrigin(preview)) return refuse(403, 'cross-origin request refused', 'a save needs the Console\'s own Origin');
  if (one(req, 'sec-fetch-site') !== 'same-origin') return refuse(403, 'cross-site request refused', 'a save needs same-origin Fetch Metadata');
  let value;
  try { value = JSON.parse((await body(req, FILE_SAVE_MAX)).toString('utf8')); } catch (err) { return refuse(400, 'invalid-request', err.message); }
@@ -460,13 +466,17 @@ async function projectFileRead(res, read, path, search) {
    return json(res, busStatus(code), { error: code, message: err instanceof BusReadError ? err.message : code });
  }
 }
-// `send` is the bus write (row 76): `args => Promise<{id}>`, only with the preview mode. `log`
+// `send` is the bus write (row 76): `args => Promise<{id}>`, only with the preview mode or `sso`.
+// `sso` is createSso() from sso.mjs (Q175 phase 1): the human listener signs people in itself.
+// `testerNoSignIn` makes the tester listener refuse anything that looks like a sign-in (--sso). `log`
 // takes one line per send attempt that got past sign-in; never the body. `fieldsFile` is for
 // tests; the field table is otherwise the committed packages/tasks/fields.json.
-export async function startServer({ host = '127.0.0.1', port = 7330, board = DEFAULT_BOARD, timeout = 20000, bus = null, reads = null, preview = null, tester = false, testerAuthHeader = null, proof = null, testerProofHeader = null, send = null, settingsWrite = null, projectFiles = null, projectFile = null, projectSave = null, chat = null, nameWrite = null, assistantStop = null, instancesWrite = null, routesWrite = null, log = line => console.log(line), fieldsFile = undefined } = {}) {
+export async function startServer({ host = '127.0.0.1', port = 7330, board = DEFAULT_BOARD, timeout = 20000, bus = null, reads = null, preview = null, sso = null, tester = false, testerNoSignIn = false, testerAuthHeader = null, proof = null, testerProofHeader = null, send = null, settingsWrite = null, projectFiles = null, projectFile = null, projectSave = null, chat = null, nameWrite = null, assistantStop = null, instancesWrite = null, routesWrite = null, log = line => console.log(line), fieldsFile = undefined } = {}) {
  if (!isLoopback(host)) throw new Error('refusing to bind to non-loopback host');
  if (host === 'localhost') host = '127.0.0.1';
  if (tester && preview !== null) throw new Error('tester listener cannot use preview mode');
+  if (tester && sso !== null) throw new Error('tester listener cannot use sso');
+  if (sso !== null && (preview !== null || proof !== null)) throw new Error('--sso cannot be combined with --auth-header, --allow-user or --proof-*');
  if (tester && host !== '127.0.0.1') throw new Error('tester listener must bind 127.0.0.1');
  // Row 177 (#1675): chat is allowed. The tester listener's chat binds the tester, so the bus keeps it on tester threads.
  if (tester && [send, settingsWrite, projectSave, assistantStop].some(value => value !== null)) throw new Error('tester listener permits only instance, route, name and chat writes');
@@ -476,21 +486,26 @@ export async function startServer({ host = '127.0.0.1', port = 7330, board = DEF
    throw new Error('preview mode needs --public-host, --auth-header and --allow-user together');
  }
  if (proof !== null && (preview === null || tester)) throw new Error('proxy proof needs preview mode');
-  if (send !== null && (preview === null || typeof send !== 'function')) throw new Error('--send needs the preview mode (--public-host, --auth-header and --allow-user)');
+  if (send !== null && ((preview === null && sso === null) || typeof send !== 'function')) throw new Error('--send needs the preview mode (--public-host, --auth-header and --allow-user) or --sso');
  const server = createServer(async (req, res) => {
    res.setHeader('x-content-type-options', 'nosniff');
    res.setHeader('referrer-policy', 'no-referrer');
-    res.setHeader('content-security-policy', "default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'; connect-src 'self'; font-src 'self'; object-src 'none'; base-uri 'none'; frame-ancestors 'none'; form-action 'self'");
+    // Under --sso the Sign out form's POST is redirected to the provider's end-session endpoint, and
+    // browsers apply form-action to that redirect, so those origins (from discovery) are allowed too.
+    res.setHeader('content-security-policy', `default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'; connect-src 'self'; font-src 'self'; object-src 'none'; base-uri 'none'; frame-ancestors 'none'; form-action 'self'${sso ? sso.formTargets().map(o => ` ${o}`).join('') : ''}`);
    // Presence, even with an empty value: never turn the public listener into a tester ingress.
    if (!tester && Object.hasOwn(req.headers, 'x-mosaic-tester')) return json(res, 403, { error: 'tester listener required' });
    if (tester && testerAuthHeader && Object.hasOwn(req.headers, testerAuthHeader.toLowerCase())) return json(res, 403, { error: 'proxy header refused' });
    if (tester && testerProofHeader && Object.hasOwn(req.headers, testerProofHeader.toLowerCase())) return json(res, 403, { error: 'proxy proof header refused' });
+    // Under --sso the tester listener reads no cookie and takes no sign-in of any kind (design section 6).
+    if (tester && testerNoSignIn && (Object.hasOwn(req.headers, 'authorization') || SIGN_IN_COOKIE.test(req.headers.cookie ?? '') || Object.keys(req.headers).some(h => h.startsWith('x-authentik-'))))
+      return json(res, 403, { error: 'tester listener takes no sign-in' });
    let path, search;
    // Node keeps the first of repeated Host headers; a second one (a loopback Host, then NAME) is
    // never legitimate, so it is refused before any check reads the Host.
    if ((req.headersDistinct.host?.length ?? 0) > 1) return json(res, 400, { error: 'repeated Host refused' });
    // Preview mode: a request for the public name, exactly, as the proxy forwards it.
-    const named = preview !== null && (req.headers.host ?? '').toLowerCase() === preview.host;
+    const named = preview !== null ? (req.headers.host ?? '').toLowerCase() === preview.host : sso !== null && (req.headers.host ?? '').toLowerCase() === sso.publicHost;
    // The proof precedes every auth-header read, including the wrong-Host fence.
    if (proof !== null) {
      const values = req.headersDistinct[proof.header];
@@ -512,19 +527,34 @@ export async function startServer({ host = '127.0.0.1', port = 7330, board = DEF
      }
      ({ pathname: path, search } = new URL(req.url, 'http://localhost'));
    } catch { return json(res, 400, { error: 'invalid URL' }); }
+    // Under --sso the human listener serves only the public Host, whatever its port; GET /healthz
+    // alone stays open on a loopback Host for the status and release gates (Q-C).
+    if (sso !== null && !named && !(path === '/healthz' && req.method === 'GET')) return json(res, 403, { error: 'public Host required' });
    // No CORS. JSON content type and same-origin checks keep browser forms out.
-    if (req.headers.origin && req.headers.origin !== (named ? `https://${preview.host}` : `http://${req.headers.host}`)) return json(res, 403, { error: 'cross-origin request refused' });
-    if (named) {
+    if (req.headers.origin && req.headers.origin !== (named ? (sso ? sso.publicOrigin : `https://${preview.host}`) : `http://${req.headers.host}`)) return json(res, 403, { error: 'cross-origin request refused' });
+    let signer = preview;
+    if (sso !== null && named) {
+      if (path.startsWith('/auth/')) return sso.handle(req, res, path, search);
+      // Only a page load or a write keeps a session alive; the page's background reads don't (Q-D).
+      const session = path === '/healthz' ? null : sso.session(req, { touch: req.method === 'POST' || (req.method === 'GET' && !path.startsWith('/api/')) });
+      if (!session && path !== '/healthz') {
+        if (path.startsWith('/api/') || req.method !== 'GET') return json(res, 401, { error: 'sign-in required' });
+        res.writeHead(303, { location: `/auth/login?return=${encodeURIComponent(path + search)}`, 'cache-control': 'no-store' });
+        return res.end();
+      }
+      if (session) signer = { sso: true, user: session.name, host: sso.publicHost, origin: sso.publicOrigin };
+    }
+    if (named && preview !== null) {
      // One value, equal to the user id; the proxy strips client copies and sets it after sign-in.
      const values = req.headersDistinct[preview.header];
      if (!values || values.length !== 1 || values[0] !== preview.user) return json(res, 401, { error: 'sign-in required' });
    }
-    const writer = tester ? { tester: true, user: 'tester', origin: `http://127.0.0.1:${server.address().port}` } : preview;
+    const writer = tester ? { tester: true, user: 'tester', origin: `http://127.0.0.1:${server.address().port}` } : signer;
    if (tester && !['GET', 'HEAD'].includes(req.method) && !['/api/instances', '/api/routes', '/api/name'].includes(path) && !TESTER_CHAT_WRITE.test(path))
      return json(res, 403, { error: 'read-only', sent: false });
    if(path==='/api/settings'&&req.method==='POST'){
      if(!send||!settingsWrite||!named)return json(res,403,{error:'read-only',sent:false});
-      return settingsSend(req,res,{settingsWrite,preview,log});
+      return settingsSend(req,res,{settingsWrite,preview:signer,log});
    }
    if (Object.hasOwn(SEAT_ROUTES, path)) {
      if (req.method !== 'POST') return json(res, 405, { error: 'method not allowed' });
@@ -544,18 +574,18 @@ export async function startServer({ host = '127.0.0.1', port = 7330, board = DEF
    }
    if (path === '/api/project-file' && req.method === 'POST') {
      if (!send || !projectSave || !named) return json(res, 403, { error: 'read-only', sent: false });
-      return projectFileSend(req, res, { projectSave, preview, log });
+      return projectFileSend(req, res, { projectSave, preview: signer, log });
    }
    // Message sending has its own bounded payload and repeats the identity check.
    if (send && path === '/api/bus/message') {
      if (req.method !== 'POST') return json(res, 405, { error: 'method not allowed' });
-      return busSend(req, res, { send, preview, log });
+      return busSend(req, res, { send, preview: signer, log });
    }
    if (path === '/api/chat' || path.startsWith('/api/chat/')) {
      return chatHTTP(req, res, { path, search, chat, named, send, preview: writer, log });
    }
    // Nothing else but GET and HEAD gets past here in preview mode, whatever the Host.
-    if (preview !== null && req.method !== 'GET' && req.method !== 'HEAD') return json(res, 403, { error: 'read-only', message: 'the Console preview is read-only' });
+    if ((preview !== null || sso !== null) && req.method !== 'GET' && req.method !== 'HEAD') return json(res, 403, { error: 'read-only', message: 'the Console preview is read-only' });
    // The conversation routes (#1507, CHAT-02) keep their query; the board validates it.
    const conversation = path === '/api/conversations' || path === '/api/conversation';
    const allowed = path === '/api/board' || conversation ? 'GET' : ['/api/seen', '/api/reply'].includes(path) ? 'POST' : null;
@@ -607,8 +637,8 @@ export async function startServer({ host = '127.0.0.1', port = 7330, board = DEF
    if (req.method !== 'GET' && req.method !== 'HEAD') return json(res, 405, { error: 'method not allowed' });
    // `send`: the page shows the composer only where a send can pass (the public name, --send on).
    // `edit`: the editor shows Save only where a save can pass, the same test as the route's.
-    if (path === '/api/config') return json(res, 200, { board: upstream, ...(tester ? { tester: true } : {}), send: !tester && Boolean(send) && named, edit: !tester && Boolean(send) && Boolean(projectSave) && named });
-    if (path === '/healthz') return json(res, 200, { ok: true });
+    if (path === '/api/config') return json(res, 200, { board: upstream, ...(tester ? { tester: true } : {}), ...(sso ? { sso: true } : {}), send: !tester && Boolean(send) && named, edit: !tester && Boolean(send) && Boolean(projectSave) && named });
+    if (path === '/healthz') return json(res, 200, { ok: true, ...(sso ? { sso: sso.health() } : {}) });
    if (path === '/favicon.ico') { res.writeHead(204); return res.end(); }
    const file = files.get(path);
    if (!file) return json(res, 404, { error: 'not found' });
@@ -0,0 +1,75 @@
+// Q175 phase 1 (#1690): the shape of config.json's optional `console` key. The one loader,
+// scripts/mosaic-config.mjs, runs this on every read, so a bad key refuses the config for every
+// tool (design section 4, C1). The Console's --sso start runs it again before it uses the value.
+// Shape only: nothing here touches the network or a slot file. A refusal names the key path and
+// never quotes a value, so a refusal can't print a client id or a subject.
+
+// The asymmetric algorithms oauth4webapi 3.8.8 verifies (its supported(), build/index.js). No HS*
+// and no none, so a client secret can never be a signing key.
+export const ALGS = Object.freeze(['PS256', 'ES256', 'RS256', 'PS384', 'ES384', 'RS384', 'PS512', 'ES512', 'RS512', 'Ed25519', 'EdDSA', 'ML-DSA-44', 'ML-DSA-65', 'ML-DSA-87']);
+const PROVIDER_ID = /^[a-z0-9-]{1,32}$/;
+const SLOT = /^[a-z0-9-]{1,64}$/;
+const SUB = /^[\x21-\x7e]{1,255}$/;
+const CLIENT_ID = /^[\x21-\x7e]{1,255}$/;
+// The name goes where the preview's --allow-user went (serve.mjs USER): visible ASCII, no comma.
+const NAME = /^[\x21-\x2b\x2d-\x7e]{1,64}$/;
+// The bus keeps these for the tester and the human role (section 6), so no subject can sign in as one.
+const RESERVED_NAMES = ['tester', 'human'];
+
+const object = v => typeof v === 'object' && v !== null && !Array.isArray(v);
+function refuse(where, why) {
+  throw new Error(`${where} ${why}`);
+}
+function keys(value, where, allowed, required = allowed) {
+  if (!object(value)) refuse(where, 'must be a JSON object');
+  for (const key of Object.keys(value)) if (!allowed.includes(key)) refuse(`${where}.${key}`, 'is not a supported key');
+  for (const key of required) if (!Object.hasOwn(value, key)) refuse(`${where}.${key}`, 'is required');
+}
+function httpsURL(value, where) {
+  let url;
+  if (typeof value !== 'string' || value.length > 512) refuse(where, 'must be an https URL of at most 512 characters');
+  try { url = new URL(value); } catch { refuse(where, 'must be an https URL'); }
+  if (url.protocol !== 'https:' || url.username || url.password || url.search || url.hash || value.includes('?') || value.includes('#')) {
+    refuse(where, 'must be https with no credentials, query or fragment');
+  }
+  return url;
+}
+
+// Returns the value unchanged when it passes; throws an Error naming the bad key path otherwise.
+export function checkConsole(value, where = 'console') {
+  keys(value, where, ['sso']);
+  const sso = value.sso, at = `${where}.sso`;
+  keys(sso, at, ['publicOrigin', 'providers']);
+  const origin = httpsURL(sso.publicOrigin, `${at}.publicOrigin`);
+  if (origin.origin !== sso.publicOrigin) refuse(`${at}.publicOrigin`, 'must be an https origin with no path, query, fragment or trailing slash');
+  if (!Array.isArray(sso.providers) || sso.providers.length === 0 || sso.providers.length > 8) refuse(`${at}.providers`, 'must be a list of 1 to 8 providers');
+  const ids = new Set();
+  sso.providers.forEach((p, i) => {
+    const pat = `${at}.providers[${i}]`;
+    keys(p, pat, ['id', 'issuer', 'clientId', 'clientSecret', 'algs', 'subjects']);
+    if (typeof p.id !== 'string' || !PROVIDER_ID.test(p.id)) refuse(`${pat}.id`, 'must match [a-z0-9-]{1,32}');
+    if (ids.has(p.id)) refuse(`${pat}.id`, 'repeats an earlier provider id');
+    ids.add(p.id);
+    httpsURL(p.issuer, `${pat}.issuer`);
+    if (typeof p.clientId !== 'string' || !CLIENT_ID.test(p.clientId)) refuse(`${pat}.clientId`, 'must be 1 to 255 visible characters');
+    keys(p.clientSecret, `${pat}.clientSecret`, ['slot']);
+    if (typeof p.clientSecret.slot !== 'string' || !SLOT.test(p.clientSecret.slot)) refuse(`${pat}.clientSecret.slot`, 'must match [a-z0-9-]{1,64}');
+    if (!Array.isArray(p.algs) || p.algs.length === 0) refuse(`${pat}.algs`, 'must be a non-empty list');
+    p.algs.forEach((alg, j) => {
+      if (!ALGS.includes(alg)) refuse(`${pat}.algs[${j}]`, `must be one of ${ALGS.join(', ')}; HS* and none are refused`);
+    });
+    if (new Set(p.algs).size !== p.algs.length) refuse(`${pat}.algs`, 'repeats an algorithm');
+    if (!Array.isArray(p.subjects) || p.subjects.length === 0 || p.subjects.length > 64) refuse(`${pat}.subjects`, 'must be a list of 1 to 64 subjects');
+    const subs = new Set();
+    p.subjects.forEach((s, j) => {
+      const sat = `${pat}.subjects[${j}]`;
+      keys(s, sat, ['sub', 'name']);
+      if (typeof s.sub !== 'string' || !SUB.test(s.sub)) refuse(`${sat}.sub`, 'must be 1 to 255 visible characters');
+      if (subs.has(s.sub)) refuse(`${sat}.sub`, 'repeats an earlier subject');
+      subs.add(s.sub);
+      if (typeof s.name !== 'string' || !NAME.test(s.name)) refuse(`${sat}.name`, 'must be 1 to 64 visible characters');
+      if (RESERVED_NAMES.includes(s.name.toLowerCase())) refuse(`${sat}.name`, `must not be ${RESERVED_NAMES.join(' or ')}`);
+    });
+  });
+  return value;
+}
@@ -0,0 +1,347 @@
+// Q175 phase 1 (#1690, design agents/sage/work/q175-sso/DESIGN.md): the Console as an OIDC relying
+// party. Used only by the human listener under --sso; startServer refuses it on the tester listener.
+// Every URL handed to a provider is built from the configured publicOrigin, never from a request's
+// Host. A refusal logs one fixed code and the provider id, never an exception, its message or its
+// cause: oauth4webapi's errors carry token bodies and claims there.
+import { createHash, randomBytes } from 'node:crypto';
+import { closeSync, constants, fstatSync, lstatSync, openSync, readFileSync, realpathSync } from 'node:fs';
+import { homedir } from 'node:os';
+import { join, relative, isAbsolute, resolve } from 'node:path';
+import { checkConsole } from './sso-config.mjs';
+
+// oauth4webapi loads in createSso, not here: cli.mjs imports this module on every start, and a
+// Console without --sso must not need the package (pinned-copy.test.mjs builds copies whose lock
+// installs nothing). A real copy installs it from the root lock.
+let oauth;
+
+export const SESSION_COOKIE = '__Host-mosaic_session';
+export const LOGIN_COOKIE = '__Host-mosaic_login';
+const ATTRS = 'Path=/; Secure; HttpOnly; SameSite=Lax';
+const LOGIN_MAX_AGE = 600;
+const SESSION_ABSOLUTE = 8 * 3600 * 1000, SESSION_IDLE = 3600 * 1000;
+const MAX_SESSIONS = 64, MAX_LOGINS = 32;
+const FETCH_TIMEOUT = 10000;
+const RETRY_CAP = 300000;
+const CODES = new Set(['login-record-missing', 'state-mismatch', 'auth-error-response', 'grant-failed', 'id-token-invalid', 'signature-invalid', 'alg-refused', 'issuer-mismatch', 'subject-unknown', 'discovery-failed', 'jwks-failed']);
+
+const sha256 = value => createHash('sha256').update(value).digest('hex');
+const escape = text => String(text).replace(/[&<>"']/g, c => `&#${c.charCodeAt(0)};`);
+const under = (parent, child) => { const rel = relative(parent, child); return rel === '' || (!rel.startsWith('..') && !isAbsolute(rel)); };
+
+// The slot file holding a provider's client secret (design section 4, D1). Only the Console's --sso
+// start calls this. A refusal names the provider and the check, never the path's contents.
+export function readSlot(configDir, provider, { repo, checkout = null, copies = join(process.env.XDG_DATA_HOME || join(homedir(), '.local', 'share'), 'mosaic-stack', 'copies') } = {}) {
+  const where = `console.sso provider ${provider.id} client secret slot`;
+  const file = join(resolve(configDir), 'secrets', 'mosaic-stack', provider.clientSecret.slot);
+  let st;
+  try { st = lstatSync(file); } catch { throw new Error(`${where} is missing`); }
+  if (st.isSymbolicLink()) throw new Error(`${where} must not be a symbolic link`);
+  let fd, real, text;
+  try {
+    fd = openSync(file, constants.O_RDONLY | constants.O_NOFOLLOW | constants.O_NONBLOCK);
+    st = fstatSync(fd);
+    if (!st.isFile()) throw new Error(`${where} must be a regular file`);
+    if (st.uid !== process.getuid()) throw new Error(`${where} must be owned by the Console's user`);
+    if (st.mode & 0o077) throw new Error(`${where} must have no group or other permission bits`);
+    real = realpathSync(file);
+    for (const root of [repo, checkout, copies].filter(Boolean)) {
+      let base;
+      try { base = realpathSync(root); } catch { base = resolve(root); }
+      if (under(base, real)) throw new Error(`${where} must not be inside the repository or a stack copy`);
+    }
+    text = readFileSync(fd, 'utf8');
+  } catch (err) {
+    throw err.message?.startsWith(where) ? err : new Error(`${where} is not readable`);
+  } finally {
+    if (fd !== undefined) closeSync(fd);
+  }
+  const secret = text.endsWith('\n') ? text.slice(0, -1) : text;
+  if (!secret || /[\r\n]/.test(secret)) throw new Error(`${where} must hold one non-empty line`);
+  return secret;
+}
+
+export function cookies(req, name) {
+  const found = [];
+  for (const part of (req.headers.cookie ?? '').split(';')) {
+    const at = part.indexOf('=');
+    if (at > 0 && part.slice(0, at).trim() === name) found.push(part.slice(at + 1).trim());
+  }
+  return found;
+}
+
+// The JWKS check at discovery, the same filter the library's key selection uses (kty, alg, use,
+// key_ops, crv; RSA at least 2048 bits), without a kid since no token is at hand yet.
+function usableKey(jwk, alg) {
+  const kty = { RS: 'RSA', PS: 'RSA', ES: 'EC', Ed: 'OKP', ML: 'AKP' }[alg.slice(0, 2)];
+  if (jwk === null || typeof jwk !== 'object' || jwk.kty !== kty) return false;
+  if (jwk.alg !== undefined && jwk.alg !== alg) return false;
+  if (jwk.use !== undefined && jwk.use !== 'sig') return false;
+  if (Array.isArray(jwk.key_ops) && !jwk.key_ops.includes('verify')) return false;
+  const crv = { ES256: 'P-256', ES384: 'P-384', ES512: 'P-521', Ed25519: 'Ed25519', EdDSA: 'Ed25519' }[alg];
+  if (crv && jwk.crv !== crv) return false;
+  if (kty === 'RSA' && (typeof jwk.n !== 'string' || Buffer.from(jwk.n, 'base64url').length * 8 < 2048)) return false;
+  return true;
+}
+
+class Unreachable extends Error {}
+class Refused extends Error {}
+const https = value => { try { return new URL(value).protocol === 'https:'; } catch { return false; } };
+
+// One provider's discovery and JWKS. Throws Unreachable (network, timeout, a status other than 200,
+// a body that isn't JSON) or Refused (a JSON document that fails a check). Q-B, design section 4.
+async function discover(p, fetchOptions) {
+  let response, text;
+  const options = () => ({ ...fetchOptions, signal: AbortSignal.timeout(FETCH_TIMEOUT) });
+  try {
+    response = await oauth.discoveryRequest(new URL(p.issuer), options());
+    if (response.status !== 200 || !/^application\/json\b/i.test(response.headers.get('content-type') ?? '')) throw new Error();
+    text = await response.text();
+    JSON.parse(text);
+  } catch { throw new Unreachable(); }
+  let as;
+  try {
+    as = await oauth.processDiscoveryResponse(new URL(p.issuer), new Response(text, { status: 200, headers: { 'content-type': 'application/json' } }));
+  } catch { throw new Refused(); }
+  if (as.issuer !== p.issuer) throw new Refused();
+  if (!Array.isArray(as.id_token_signing_alg_values_supported) || !p.algs.some(a => as.id_token_signing_alg_values_supported.includes(a))) throw new Refused();
+  if (!Array.isArray(as.code_challenge_methods_supported) || !as.code_challenge_methods_supported.includes('S256')) throw new Refused();
+  if (![as.authorization_endpoint, as.token_endpoint, as.jwks_uri].every(https)) throw new Refused();
+  if (as.end_session_endpoint !== undefined && !https(as.end_session_endpoint)) throw new Refused();
+  let jwks;
+  try {
+    const fetcher = fetchOptions[oauth.customFetch] ?? fetch;
+    const res = await fetcher(as.jwks_uri, { method: 'GET', headers: { accept: 'application/json, application/jwk-set+json' }, redirect: 'manual', signal: AbortSignal.timeout(FETCH_TIMEOUT) });
+    if (res.status !== 200) throw new Error();
+    jwks = JSON.parse(await res.text());
+  } catch { throw new Unreachable(); }
+  if (jwks === null || typeof jwks !== 'object' || !Array.isArray(jwks.keys)) throw new Refused();
+  const usable = p.algs.filter(alg => jwks.keys.some(k => usableKey(k, alg)));
+  if (!usable.length) throw new Refused();
+  return as;
+}
+
+// `config` is console.sso, checked again here; `secrets` maps provider id to its client secret
+// (readSlot). `fetch` is for tests: a fetch that trusts only the fake OP's certificate.
+// `retryFirst` is for tests too; production waits 5 s, doubling, capped at 5 minutes.
+export async function createSso(config, { secrets, fetch: customFetch = null, log = line => console.log(line), retryFirst = 5000 } = {}) {
+  checkConsole({ sso: config });
+  oauth ??= await import('oauth4webapi');
+  const publicOrigin = config.publicOrigin;
+  const publicHost = new URL(publicOrigin).host;
+  const redirectUri = `${publicOrigin}/auth/callback`;
+  const fetchOptions = customFetch ? { [oauth.customFetch]: customFetch } : {};
+  const sessions = new Map(), logins = new Map();
+  const timers = new Set();
+  let closed = false;
+  const refuse = (code, provider, extra = '') => {
+    if (!CODES.has(code)) throw new Error(`unknown sso log code ${code}`);
+    log(`${new Date().toISOString()} sso refused code=${code} provider=${provider}${extra}`);
+  };
+
+  const providers = new Map(config.providers.map(p => {
+    if (typeof secrets?.get(p.id) !== 'string') throw new Error(`console.sso provider ${p.id} has no client secret`);
+    return [p.id, {
+      config: p, state: 'unreachable', as: null, jwks: {},
+      client: { client_id: p.clientId, id_token_signed_response_alg: [...p.algs] },
+      auth: oauth.ClientSecretBasic(secrets.get(p.id)),
+      subjects: new Map(p.subjects.map(s => [s.sub, s.name])),
+    }];
+  }));
+
+  async function attempt(entry, atStart) {
+    try {
+      entry.as = await discover(entry.config, fetchOptions);
+      entry.jwks = {};
+      entry.state = 'ready';
+    } catch (err) {
+      if (err instanceof Refused) {
+        entry.state = 'refused';
+        refuse('discovery-failed', entry.config.id);
+        if (atStart) throw new Error(`console.sso provider ${entry.config.id} refused at discovery: the issuer, algorithms, S256 or JWKS check failed`);
+        return;
+      }
+      entry.state = 'unreachable';
+      refuse('discovery-failed', entry.config.id);
+      throw err;
+    }
+  }
+  function retry(entry, delay) {
+    if (closed) return;
+    const timer = setTimeout(async () => {
+      timers.delete(timer);
+      try { await attempt(entry, false); } catch { retry(entry, Math.min(delay * 2, RETRY_CAP)); }
+    }, delay);
+    timer.unref();
+    timers.add(timer);
+  }
+  for (const entry of providers.values()) {
+    try { await attempt(entry, true); } catch (err) {
+      if (!(err instanceof Unreachable)) throw err;
+      retry(entry, retryFirst);
+    }
+  }
+
+  const page = (res, status, title, html, headers = {}) => {
+    res.writeHead(status, { 'content-type': 'text/html; charset=utf-8', 'cache-control': 'no-store', ...headers });
+    res.end(`<!doctype html><meta charset="utf-8"><title>${escape(title)}</title><main style="font-family:sans-serif;max-width:32rem;margin:4rem auto"><h1>${escape(title)}</h1>${html}</main>\n`);
+  };
+  const redirect = (res, location, setCookie = []) => {
+    res.writeHead(303, { location, 'cache-control': 'no-store', ...(setCookie.length ? { 'set-cookie': setCookie } : {}) });
+    res.end();
+  };
+  const failed = (res, setCookie = []) => page(res, 403, 'Sign-in failed', '<p><a href="/auth/login">Sign in again</a></p>', setCookie.length ? { 'set-cookie': setCookie } : {});
+  const expire = name => `${name}=; ${ATTRS}; Max-Age=0`;
+  const remember = (map, key, value, cap) => {
+    while (map.size >= cap) map.delete(map.keys().next().value);
+    map.set(key, value);
+  };
+
+  // B2: only a URL on publicOrigin itself; anything else, or nothing, is publicOrigin's `/`. The
+  // Location is absolute and its origin checked again: dot segments can leave a pathname of `//host`,
+  // which as a relative Location a browser reads as another origin (webby-0019 B1, sage-1403).
+  function returnURL(ret) {
+    const home = `${publicOrigin}/`;
+    try {
+      if (typeof ret !== 'string' || !ret) return home;
+      const u = new URL(ret, publicOrigin);
+      if (u.origin !== publicOrigin) return home;
+      const out = new URL(`${publicOrigin}${u.pathname}${u.search}`);
+      return out.origin === publicOrigin ? out.href : home;
+    } catch { return home; }
+  }
+
+  async function start(res, entry, ret) {
+    const state = oauth.generateRandomState(), nonce = oauth.generateRandomNonce(), verifier = oauth.generateRandomCodeVerifier();
+    const challenge = await oauth.calculatePKCECodeChallenge(verifier);
+    const id = randomBytes(32).toString('base64url');
+    remember(logins, sha256(id), { provider: entry.config.id, state, nonce, verifier, ret: typeof ret === 'string' ? ret.slice(0, 2048) : '/', expires: Date.now() + LOGIN_MAX_AGE * 1000 }, MAX_LOGINS);
+    const url = new URL(entry.as.authorization_endpoint);
+    for (const [k, v] of Object.entries({ client_id: entry.config.clientId, response_type: 'code', scope: 'openid profile email', redirect_uri: redirectUri, state, nonce, code_challenge: challenge, code_challenge_method: 'S256' })) url.searchParams.set(k, v);
+    return redirect(res, url.href, [`${LOGIN_COOKIE}=${id}; ${ATTRS}; Max-Age=${LOGIN_MAX_AGE}`]);
+  }
+
+  function login(res, query) {
+    const asked = query.get('provider');
+    const ret = query.get('return');
+    if (asked === null && providers.size > 1) {
+      const items = [...providers.values()].map(e => `<li><a href="/auth/login?${escape(new URLSearchParams({ provider: e.config.id, ...(ret ? { return: ret } : {}) }))}">${escape(e.config.id)}</a></li>`).join('');
+      return page(res, 200, 'Sign in', `<ul>${items}</ul>`);
+    }
+    const entry = asked === null ? [...providers.values()][0] : providers.get(asked);
+    if (!entry) return page(res, 404, 'Unknown sign-in provider', '<p><a href="/auth/login">Sign in</a></p>');
+    if (entry.state !== 'ready') return page(res, 503, 'sign-in unavailable', '<p>The sign-in provider can\'t be reached. Try again shortly.</p>');
+    return start(res, entry, ret);
+  }
+
+  // Design section 1, steps 2-7. Each refusal ends here with one log line and the 403 page.
+  async function callback(res, query, req) {
+    const clear = [expire(LOGIN_COOKIE)];
+    const ids = cookies(req, LOGIN_COOKIE);
+    const key = ids.length === 1 ? sha256(ids[0]) : null;
+    const record = key === null ? undefined : logins.get(key);
+    if (key !== null) logins.delete(key);
+    // The provider comes from the record, never from the query.
+    const entry = record && providers.get(record.provider);
+    if (!record || record.expires <= Date.now() || !entry) {
+      refuse('login-record-missing', record?.provider ?? 'none');
+      return failed(res, clear);
+    }
+    const pid = entry.config.id;
+    if (entry.state !== 'ready') { refuse('discovery-failed', pid); return failed(res, clear); }
+    let params;
+    try { params = oauth.validateAuthResponse(entry.as, entry.client, query, record.state); } catch (err) {
+      refuse(err instanceof oauth.AuthorizationResponseError ? 'auth-error-response' : 'state-mismatch', pid);
+      return failed(res, clear);
+    }
+    const options = () => ({ ...fetchOptions, [oauth.jwksCache]: entry.jwks, signal: AbortSignal.timeout(FETCH_TIMEOUT) });
+    let response;
+    try { response = await oauth.authorizationCodeGrantRequest(entry.as, entry.client, entry.auth, params, redirectUri, record.verifier, options()); } catch {
+      refuse('grant-failed', pid); return failed(res, clear);
+    }
+    let result, claims;
+    try {
+      result = await oauth.processAuthorizationCodeResponse(entry.as, entry.client, response, { expectedNonce: record.nonce, requireIdToken: true });
+      claims = oauth.getValidatedIdTokenClaims(result);
+    } catch (err) {
+      refuse(err instanceof oauth.ResponseBodyError ? 'grant-failed' : 'id-token-invalid', pid);
+      return failed(res, clear);
+    }
+    // Step 5: the library skips this for a token-endpoint ID token; point 2 needs it, on the same
+    // Response object. Its throw ends the callback.
+    try { await oauth.validateApplicationLevelSignature(entry.as, response, options()); } catch (err) {
+      const fetching = !(err instanceof oauth.OperationProcessingError || err instanceof oauth.UnsupportedOperationError) || [oauth.RESPONSE_IS_NOT_CONFORM, oauth.RESPONSE_IS_NOT_JSON].includes(err.code);
+      refuse(fetching ? 'jwks-failed' : 'signature-invalid', pid);
+      return failed(res, clear);
+    }
+    // Step 6: our own checks on top of the library's.
+    let header;
+    try { header = JSON.parse(Buffer.from(result.id_token.split('.')[0], 'base64url').toString('utf8')); } catch { header = null; }
+    if (!header || !entry.config.algs.includes(header.alg)) { refuse('alg-refused', pid); return failed(res, clear); }
+    if (claims.iss !== entry.config.issuer) { refuse('issuer-mismatch', pid); return failed(res, clear); }
+    const name = typeof claims.sub === 'string' ? entry.subjects.get(claims.sub) : undefined;
+    if (name === undefined) {
+      refuse('subject-unknown', pid, ` iss=${JSON.stringify(String(claims.iss).slice(0, 255))} sub=${JSON.stringify(String(claims.sub).slice(0, 255))}`);
+      return failed(res, clear);
+    }
+    // Step 7: the session, then the return path.
+    const id = randomBytes(32).toString('base64url'), now = Date.now();
+    remember(sessions, sha256(id), { provider: pid, iss: claims.iss, sub: claims.sub, name, idToken: result.id_token, created: now, seen: now }, MAX_SESSIONS);
+    return redirect(res, returnURL(record.ret), [...clear, `${SESSION_COOKIE}=${id}; ${ATTRS}`]);
+  }
+
+  // The session for this request, or null. `touch` is true only for a page load or a write (Q-D).
+  function session(req, { touch = false } = {}) {
+    const ids = cookies(req, SESSION_COOKIE);
+    if (ids.length !== 1) return null;
+    const key = sha256(ids[0]);
+    const s = sessions.get(key);
+    if (!s) return null;
+    const now = Date.now();
+    if (now - s.created >= SESSION_ABSOLUTE || now - s.seen >= SESSION_IDLE) { sessions.delete(key); return null; }
+    if (touch) s.seen = now;
+    return s;
+  }
+
+  function logout(req, res) {
+    const one = name => (req.headersDistinct[name]?.length === 1 ? req.headersDistinct[name][0] : null);
+    if (one('origin') !== publicOrigin || one('sec-fetch-site') !== 'same-origin') {
+      return page(res, 403, 'Sign-out refused', '<p>Sign out from the Console page.</p>');
+    }
+    const ids = cookies(req, SESSION_COOKIE);
+    const key = ids.length === 1 ? sha256(ids[0]) : null;
+    const s = key === null ? undefined : sessions.get(key);
+    if (key !== null) sessions.delete(key);
+    const entry = s && providers.get(s.provider);
+    let location = `${publicOrigin}/auth/signed-out`;
+    if (entry?.as?.end_session_endpoint) {
+      const url = new URL(entry.as.end_session_endpoint);
+      url.searchParams.set('id_token_hint', s.idToken);
+      url.searchParams.set('post_logout_redirect_uri', `${publicOrigin}/auth/signed-out`);
+      url.searchParams.set('client_id', entry.config.clientId);
+      location = url.href;
+    }
+    return redirect(res, location, [expire(SESSION_COOKIE)]);
+  }
+
+  // `/auth/*` on the human listener; the caller has already checked the Host.
+  async function handle(req, res, path, search) {
+    const query = new URLSearchParams(search);
+    if (path === '/auth/logout') {
+      if (req.method !== 'POST') return page(res, 405, 'Method not allowed', '');
+      return logout(req, res);
+    }
+    if (req.method !== 'GET') return page(res, 405, 'Method not allowed', '');
+    if (path === '/auth/login') return login(res, query);
+    if (path === '/auth/callback') return callback(res, query, req);
+    if (path === '/auth/signed-out') return page(res, 200, 'Signed out', '<p><a href="/auth/login">Sign in</a></p>');
+    return page(res, 404, 'Not found', '');
+  }
+
+  return {
+    publicOrigin, publicHost, sessions, logins, handle, session, returnURL,
+    health: () => Object.fromEntries([...providers].map(([id, e]) => [id, e.state])),
+    formTargets: () => [...new Set([...providers.values()].filter(e => e.as?.end_session_endpoint).map(e => new URL(e.as.end_session_endpoint).origin))],
+    summary: () => config.providers.map(p => ({ id: p.id, issuer: p.issuer, subjects: p.subjects.length })),
+    close() { closed = true; for (const t of timers) clearTimeout(t); timers.clear(); },
+  };
+}
@@ -23,6 +23,7 @@ StartLimitBurst=5
 Type=simple
 WorkingDirectory=@REPO@
 Environment=PATH=@PATH@
+@CONFIG_ENV@
 # The server binds 127.0.0.1 only. Usage, config and listen refusals
 # (a port already in use included) exit 2 and are not retried; fix the
 # flags or free the port, then start it again.
@@ -0,0 +1,155 @@
+// Q175 phase 1 (#1690, design section 9): a fake OpenID provider for the --sso tests. A loopback
+// https server with a self-signed certificate made in a temp dir; `op.fetch` is a fetch that trusts
+// only that certificate, so the code under test needs no insecure flag. It serves any number of
+// issuers (`/<name>/`) at once, each with discovery, a JWKS, authorization, token and end-session
+// endpoints. Keys come from node:crypto. Nothing here reaches any other host.
+import { constants, createHash, createHmac, generateKeyPairSync, randomBytes, sign } from 'node:crypto';
+import { spawnSync } from 'node:child_process';
+import { mkdtempSync, readFileSync, rmSync } from 'node:fs';
+import { createServer, request } from 'node:https';
+import { tmpdir } from 'node:os';
+import { join } from 'node:path';
+
+export const b64url = value => Buffer.from(typeof value === 'string' ? value : JSON.stringify(value)).toString('base64url');
+
+export function rsaKey(kid = `rsa-${randomBytes(4).toString('hex')}`, bits = 2048) {
+  const { privateKey, publicKey } = generateKeyPairSync('rsa', { modulusLength: bits });
+  return { kid, alg: 'RS256', privateKey, jwk: { ...publicKey.export({ format: 'jwk' }), kid, use: 'sig', alg: 'RS256' } };
+}
+export function ecKey(kid = `ec-${randomBytes(4).toString('hex')}`) {
+  const { privateKey, publicKey } = generateKeyPairSync('ec', { namedCurve: 'P-256' });
+  return { kid, alg: 'ES256', privateKey, jwk: { ...publicKey.export({ format: 'jwk' }), kid, use: 'sig', alg: 'ES256' } };
+}
+export function psKey(kid = `ps-${randomBytes(4).toString('hex')}`) {
+  const k = rsaKey(kid);
+  return { ...k, alg: 'PS256', jwk: { ...k.jwk, alg: 'PS256' } };
+}
+
+// A compact JWS. `alg` HS256 uses `hmac` as the key, `none` has an empty signature.
+export function jwt(header, payload, { key = null, hmac = null } = {}) {
+  const input = `${b64url(header)}.${b64url(payload)}`;
+  let sig = '';
+  if (header.alg === 'HS256') sig = createHmac('sha256', hmac).update(input).digest('base64url');
+  else if (header.alg === 'RS256') sig = sign('sha256', Buffer.from(input), key).toString('base64url');
+  else if (header.alg === 'PS256') sig = sign('sha256', Buffer.from(input), { key, padding: constants.RSA_PKCS1_PSS_PADDING, saltLength: 32 }).toString('base64url');
+  else if (header.alg === 'ES256') sig = sign('sha256', Buffer.from(input), { key, dsaEncoding: 'ieee-p1363' }).toString('base64url');
+  return `${input}.${sig}`;
+}
+
+function certificate() {
+  const dir = mkdtempSync(join(tmpdir(), 'fake-oidc-'));
+  try {
+    const r = spawnSync('openssl', ['req', '-x509', '-newkey', 'ec', '-pkeyopt', 'ec_paramgen_curve:P-256', '-nodes', '-days', '1',
+      '-subj', '/CN=127.0.0.1', '-addext', 'subjectAltName=IP:127.0.0.1', '-keyout', join(dir, 'key.pem'), '-out', join(dir, 'cert.pem')], { encoding: 'utf8' });
+    if (r.status !== 0) throw new Error(`openssl failed: ${r.stderr}`);
+    return { key: readFileSync(join(dir, 'key.pem')), cert: readFileSync(join(dir, 'cert.pem')) };
+  } finally { rmSync(dir, { recursive: true, force: true }); }
+}
+
+// One issuer's state. `discovery` is merged over the defaults; `mode` is 'ok', 'down' (the socket is
+// destroyed) or 'html' (200 with an HTML page) for discovery.
+function issuerState(name, base, opts) {
+  const keys = opts.keys ?? [rsaKey()];
+  return {
+    name, issuer: `${base}/${name}/`, keys, retired: [], clientId: opts.clientId ?? `client-${name}`, clientSecret: opts.clientSecret ?? `secret-${name}-${randomBytes(6).toString('hex')}`,
+    discovery: opts.discovery ?? {}, mode: 'ok', jwksOverride: null, codes: new Map(), acceptTwice: false, requirePkce: true,
+    tokenRequests: [], authorizeRequests: [], jwksFetches: 0, discoveryFetches: 0,
+  };
+}
+
+export async function fakeOidc() {
+  const { key, cert } = certificate();
+  const issuers = new Map();
+  const server = createServer({ key, cert }, (req, res) => {
+    const url = new URL(req.url, 'https://127.0.0.1');
+    const [, name, ...rest] = url.pathname.split('/');
+    const iss = issuers.get(name);
+    const route = rest.join('/');
+    const json = (status, body, type = 'application/json') => { res.writeHead(status, { 'content-type': type }); res.end(typeof body === 'string' ? body : JSON.stringify(body)); };
+    if (!iss) return json(404, { error: 'no issuer' });
+    if (route === '.well-known/openid-configuration') {
+      iss.discoveryFetches++;
+      if (iss.mode === 'down') return req.socket.destroy();
+      if (iss.mode === 'html') return json(200, '<!doctype html><title>Sign in</title>', 'text/html');
+      return json(200, discovery(iss));
+    }
+    if (route === 'jwks') {
+      iss.jwksFetches++;
+      return json(200, iss.jwksOverride ?? { keys: iss.keys.map(k => k.jwk) });
+    }
+    if (route === 'authorize') { iss.authorizeRequests.push(Object.fromEntries(url.searchParams)); return json(200, { ok: true }); }
+    if (route === 'end-session') return json(200, { ok: true });
+    if (route === 'token' && req.method === 'POST') {
+      let text = '';
+      req.on('data', c => (text += c));
+      req.on('end', () => {
+        const form = new URLSearchParams(text);
+        const basic = Buffer.from((req.headers.authorization ?? '').replace(/^Basic /, ''), 'base64').toString();
+        const [id, secret] = basic.split(':').map(decodeURIComponent);
+        iss.tokenRequests.push({ form: Object.fromEntries(form), clientId: id });
+        if (id !== iss.clientId || secret !== iss.clientSecret) return json(401, { error: 'invalid_client' });
+        const grant = iss.codes.get(form.get('code'));
+        if (!grant) return json(400, { error: 'invalid_grant' });
+        if (!iss.acceptTwice) iss.codes.delete(form.get('code'));
+        if (form.get('redirect_uri') !== grant.redirectUri) return json(400, { error: 'invalid_grant', error_description: 'redirect_uri' });
+        if (iss.requirePkce && createHash('sha256').update(form.get('code_verifier') ?? '').digest('base64url') !== grant.challenge) return json(400, { error: 'invalid_grant', error_description: 'pkce' });
+        return json(200, { access_token: randomBytes(16).toString('hex'), token_type: 'Bearer', expires_in: 300, id_token: grant.idToken });
+      });
+      return;
+    }
+    return json(404, { error: 'not found' });
+  });
+  await new Promise(r => server.listen(0, '127.0.0.1', r));
+  const base = `https://127.0.0.1:${server.address().port}`;
+
+  const discovery = iss => ({
+    issuer: iss.issuer, authorization_endpoint: `${iss.issuer}authorize`, token_endpoint: `${iss.issuer}token`, jwks_uri: `${iss.issuer}jwks`,
+    end_session_endpoint: `${iss.issuer}end-session`, response_types_supported: ['code'], subject_types_supported: ['public'],
+    id_token_signing_alg_values_supported: [...new Set(iss.keys.map(k => k.alg))], code_challenge_methods_supported: ['S256'],
+    ...iss.discovery,
+  });
+
+  // A fetch over node:https that trusts only this certificate. oauth4webapi passes a Headers object
+  // and a string or URLSearchParams body.
+  const opFetch = (input, init = {}) => new Promise((resolve, reject) => {
+    const url = new URL(typeof input === 'string' ? input : input.href ?? input.url);
+    if (url.protocol !== 'https:' || url.hostname !== '127.0.0.1' || url.port !== String(server.address().port)) return reject(new TypeError(`fake OP fetch refuses ${url.origin}`));
+    const headers = Object.fromEntries(new Headers(init.headers ?? {}));
+    const body = init.body === undefined || init.body === null ? undefined : String(init.body);
+    if (body !== undefined) headers['content-length'] = Buffer.byteLength(body);
+    const req = request(url, { method: init.method ?? 'GET', headers, ca: cert, signal: init.signal }, res => {
+      const chunks = [];
+      res.on('data', c => chunks.push(c));
+      res.on('end', () => {
+        const h = new Headers();
+        for (const [k, v] of Object.entries(res.headers)) h.set(k, Array.isArray(v) ? v.join(', ') : v);
+        const response = new Response(res.statusCode === 204 ? null : Buffer.concat(chunks), { status: res.statusCode, headers: h });
+        Object.defineProperty(response, 'url', { value: url.href });
+        resolve(response);
+      });
+      res.on('error', reject);
+    });
+    req.on('error', reject);
+    req.end(body);
+  });
+
+  return {
+    base, fetch: opFetch, cert,
+    issuer(name, opts = {}) { const iss = issuerState(name, base, opts); issuers.set(name, iss); return iss; },
+    // A code for `iss` whose ID token is built from the start redirect's nonce, the claims and header
+    // overrides. `challenge` defaults to the start redirect's; `idToken` replaces the token outright.
+    grant(iss, authorizeUrl, { sub = `user-${iss.name}`, claims = {}, header = {}, key = iss.keys[0], idToken = null, challenge = null, redirectUri = null } = {}) {
+      const q = new URL(authorizeUrl).searchParams;
+      const now = Math.floor(Date.now() / 1000);
+      const payload = { iss: iss.issuer, sub, aud: iss.clientId, iat: now, exp: now + 300, nonce: q.get('nonce'), ...claims };
+      for (const [k, v] of Object.entries(payload)) if (v === undefined) delete payload[k];
+      const token = idToken ?? jwt({ alg: key.alg, kid: key.kid, typ: 'JWT', ...header }, payload, { key: key.privateKey, hmac: iss.clientSecret });
+      const code = randomBytes(12).toString('base64url');
+      iss.codes.set(code, { idToken: token, challenge: challenge ?? q.get('code_challenge'), redirectUri: redirectUri ?? q.get('redirect_uri') });
+      return { code, idToken: token, payload };
+    },
+    rotate(iss, next = rsaKey()) { iss.retired.push(...iss.keys); iss.keys = [next]; return next; },
+    close: () => new Promise(r => { server.close(r); server.closeAllConnections(); }),
+  };
+}
+
@@ -146,8 +146,10 @@ test('copy refuses a commit off refactor, an unknown one, a worktree and a bad c
 test('copy writes nothing when an archived path is missing at the commit', async (t) => {
  const { dir, repo, script } = fixtureRepo(t);
  const copies = join(dir, 'copies');
-  git(repo, 'rm', '-q', 'scripts/mosaic-config.mjs');
-  git(repo, 'commit', '-q', '-m', 'drop the config check');
+  // Row 190: the entry point runs scripts/mosaic-config.mjs to select the
+  // instance before it copies, so the missing path is one only the copy reads.
+  git(repo, 'rm', '-q', 'packages/webui/README.md');
+  git(repo, 'commit', '-q', '-m', 'drop the Console README');
  git(repo,'update-ref','refs/remotes/origin/refactor',git(repo,'rev-parse','HEAD'));
  const r = await run(dir, script, ['copy', 'refactor', '--copies', copies]);
  assert.equal(r.status, 1);
@@ -30,16 +30,17 @@ function fakeCopy(dir) {
  writeFileSync(join(copyRoot(dir), 'packages', 'webui', 'src', 'cli.mjs'), '');
  return copyRoot(dir);
 }
-const SEND_REFUSAL = /^webui-service: --send needs the preview mode \(--public-host, --auth-header and --allow-user\)$/m;
+const SEND_REFUSAL = /^webui-service: --send needs the preview mode \(--public-host, --auth-header and --allow-user\) or --sso$/m;
 const TEMPLATE = readFileSync(join(REPO, 'packages', 'webui', 'systemd', 'mosaic-webui.service.in'), 'utf8');

 // The unit as the base script renders it (row 75): the template with its four
 // placeholders filled in, nothing else. Row 83 adds --send and must leave
-// every unit rendered without it byte for byte as this.
+// every unit rendered without it byte for byte as this. Row 190: the
+// default instance deletes the @CONFIG_ENV@ line, so the unit is unchanged.
 function filled(flags, root = REPO) {
  const base = '/usr/local/bin:/usr/bin:/bin';
  const path = `:${base}:`.includes(`:${NODE_DIR}:`) ? base : `${NODE_DIR}:${base}`;
-  return TEMPLATE.replaceAll('@REPO@', root).replaceAll('@PATH@', path).replaceAll('@NODE@', process.execPath).replaceAll('@FLAGS@', flags);
+  return TEMPLATE.replace('@CONFIG_ENV@\n', '').replaceAll('@REPO@', root).replaceAll('@PATH@', path).replaceAll('@NODE@', process.execPath).replaceAll('@FLAGS@', flags);
 }

 // A loopback port with nothing listening, so status's /healthz request
@@ -0,0 +1,132 @@
+// Q175 phase 1 (#1690, design test 24, sage-1340 F1, sage-1347 F7): the page under --sso. A read
+// the Console answers 401 `sign-in required` signs the page out the way a proxy redirect does, and
+// the line links to /auth/login with the current path and query; any other 401 stays an error. Both
+// fetch paths in app.js and both in bus.js (fetchRead and fetchApi) do it. The Sign out form shows
+// only when /api/config says sso. The board-held.test.mjs stub, with two lists of paths: those in
+// window.__signIn answer 401 `sign-in required`, those in window.__other 401 `unauthenticated`. A
+// page URL holding `sso` gets `sso: true` added to /api/config. Poll timers fire after 150 ms.
+import { test } from 'node:test';
+import assert from 'node:assert/strict';
+import { mkdtempSync, rmSync } from 'node:fs';
+import { tmpdir } from 'node:os';
+import { join } from 'node:path';
+import { Store } from '../../bus/src/store.mjs';
+import { Broker } from '../../bus/src/broker.mjs';
+import { views } from '../../bus/src/views.mjs';
+import { startServer } from '../src/serve.mjs';
+import { browser } from './browser.mjs';
+import { fixture, close } from './fixture.mjs';
+
+const businesses = { demo: { id: 'demo', human: 'jason', arbiters: { technical: 'cto', delivery: 'pm' }, roles: { pm: { authority: { withinRole: ['message.send'], crossRole: [] } }, cto: { authority: { withinRole: ['message.send'], crossRole: [] } } } } };
+
+const stub = `(() => {
+  const real = window.fetch.bind(window);
+  window.__reqs = []; window.__signIn = []; window.__other = [];
+  const timeout = window.setTimeout.bind(window);
+  window.setTimeout = (f, ms, ...rest) => timeout(f, ms === 10000 ? 150 : ms, ...rest);
+  const answer = (status, body) => new Response(JSON.stringify(body), { status, headers: { 'content-type': 'application/json' } });
+  window.fetch = async (url, init = {}) => {
+    const path = String(url).split('?')[0];
+    window.__reqs.push(path);
+    if (window.__signIn.includes(path)) return answer(401, { error: 'sign-in required' });
+    if (window.__other.includes(path)) return answer(401, { error: 'unauthenticated' });
+    if (path === '/api/config' && /sso/.test(location.search)) return answer(200, { ...(await (await real(url, init)).json()), sso: true });
+    return real(url, init);
+  };
+})();`;
+
+async function setup() {
+  const root = mkdtempSync(join(tmpdir(), 'webui-sso-browser-'));
+  const store = new Store(root), b0 = new Broker({ store, businesses });
+  b0.request(b0.bindLaunch({ business: 'demo', role: 'pm', run: 'pm-run', harness: 'pi', address: 'pm-run' }), { verb: 'role.claim' });
+  const reader = b0.bindReader({ business: 'demo' });
+  const bus = views({ call: async (verb, args = {}) => structuredClone(b0.request(reader, { verb, args })) });
+  const f = await fixture(), b = await browser({ machine: true });
+  const web = await startServer({ port: 0, board: f.boardURL, bus }), base = `http://127.0.0.1:${web.address().port}/`;
+  await b.call('Page.addScriptToEvaluateOnNewDocument', { source: stub });
+  await b.viewport(1280);
+  const wait = expr => b.evaluate(`(async()=>{for(let i=0;i<100;i++){if(${expr})return true;await new Promise(r=>setTimeout(r,50))}throw new Error('Condition timed out: '+${JSON.stringify(expr)})})()`);
+  const text = sel => b.evaluate(`document.querySelector(${JSON.stringify(sel)})?.textContent ?? null`);
+  const shown = sel => b.evaluate(`(()=>{const e=document.querySelector(${JSON.stringify(sel)});return !!e && !e.hidden && getComputedStyle(e).display !== 'none' && !!e.getClientRects().length})()`);
+  const reqs = () => b.evaluate('window.__reqs.length');
+  const settle = () => new Promise(r => setTimeout(r, 600));
+  const done = async () => { await b.close(); await close(web); await f.close(); store.close(); rmSync(root, { recursive: true, force: true }); };
+  return { b, base, wait, text, shown, reqs, settle, done };
+}
+
+const LOADED = 'document.querySelector("table.sessions [data-open=\'proj/agent1\']")';
+const LINE = 'Signed out. Sign in again.';
+
+test('a 401 sign-in required on each fetch path signs the page out with a sign-in link and stops the refresh; another 401 stays an error', { timeout: 120000 }, async () => {
+  const { b, base, wait, text, shown, reqs, settle, done } = await setup();
+  // The line, its link back to this page, the Sign out form gone, and no further fetch.
+  const out = async ret => {
+    await wait('!document.querySelector("#signed-out").hidden');
+    assert.equal(await text('#signed-out'), LINE);
+    assert.equal(await b.evaluate('document.querySelector("#signed-out a").getAttribute("href")'), `/auth/login?return=${encodeURIComponent(ret)}`);
+    assert.equal(await shown('#sign-out'), false);
+    assert.equal(await b.evaluate('document.querySelector("#refresh").disabled'), true);
+    const n = await reqs();
+    await b.evaluate('document.querySelector("#refresh").click(), true');
+    await settle();
+    assert.equal(await reqs(), n, 'the page fetched after signing out');
+  };
+  try {
+    // app.js api(): the Board read, with sso on from /api/config.
+    await b.navigate(`${base}?sso&x=1`);
+    await wait(LOADED);
+    await b.evaluate(`window.__signIn.push('/api/board'), document.querySelector('#refresh').click(), true`);
+    await out('/?sso&x=1');
+
+    // app.js getJSON: the conversation catalogue behind History.
+    await b.navigate(`${base}?sso&conv`);
+    await wait(LOADED);
+    await b.evaluate(`window.__signIn.push('/api/conversations'), document.querySelector('table.sessions [data-history="proj/agent1"]').click(), true`);
+    await out('/?sso&conv');
+
+    // app.js api(): the board POST behind Seen.
+    await b.navigate(`${base}?sso&seen`);
+    await wait(LOADED);
+    await b.evaluate(`document.querySelector('table.sessions [data-open="proj/agent1"]').click(), true`);
+    await wait('document.querySelector("#inspection [data-seen]")');
+    await b.evaluate(`window.__signIn.push('/api/seen'), document.querySelector('#inspection [data-seen]').click(), true`);
+    await out('/?sso&seen');
+
+    // bus.js fetchRead and fetchApi, on a page whose /api/config has no sso: the link comes from
+    // the 401 itself (F1).
+    await b.navigate(`${base}?read#/inbox`);
+    await wait(LOADED);
+    await b.evaluate(`window.__signIn.push('/api/bus/inbox'), document.querySelector('#refresh').click(), true`);
+    await out('/?read');
+    await b.navigate(`${base}?module`);
+    await wait(LOADED);
+    await b.evaluate(`window.__signIn.push('/api/queue'), location.hash = '#/queue', true`);
+    await out('/?module');
+
+    // Any other 401 is an error: no sign-out, and the polls go on.
+    await b.navigate(`${base}?sso&other`);
+    await wait(LOADED);
+    await b.evaluate(`window.__other.push('/api/board', '/api/bus/inbox', '/api/queue'), document.querySelector('#refresh').click(), true`);
+    await settle();
+    assert.equal(await b.evaluate('document.querySelector("#signed-out").hidden'), true);
+    assert.equal(await b.evaluate('document.body.classList.contains("signed-out")'), false);
+    const n = await reqs();
+    await settle();
+    assert.ok(await reqs() > n, 'the refresh stopped on another 401');
+    assert.equal(await shown('#sign-out'), true);
+  } finally { await done(); }
+});
+
+test('the Sign out form shows only when /api/config says sso, and posts to /auth/logout', { timeout: 120000 }, async () => {
+  const { b, base, wait, shown, done } = await setup();
+  try {
+    await b.navigate(base);
+    await wait(LOADED);
+    await new Promise(r => setTimeout(r, 300));
+    assert.equal(await shown('#sign-out'), false);
+    await b.navigate(`${base}?sso`);
+    await wait(`${LOADED} && !document.querySelector("#sign-out").hidden`);
+    assert.equal(await shown('#sign-out'), true);
+    assert.deepEqual(await b.evaluate('(() => { const f = document.querySelector("#sign-out"); return [f.method, f.getAttribute("action"), f.querySelector("button").textContent, f.querySelector("button").type]; })()'), ['post', '/auth/logout', 'Sign out', 'submit']);
+  } finally { await done(); }
+});
@@ -0,0 +1,589 @@
+// Q175 phase 1 (#1690, design agents/sage/work/q175-sso/DESIGN.md section 9): the Console as an
+// OIDC relying party (--sso). Every provider is the fake OP in helpers/fake-oidc.mjs on loopback;
+// no test reaches a real provider, the live Console or a real config or slot file. The public name
+// is console.example.test, sent only as a Host header to the test's own loopback listener. Each
+// refusal checks the status, that no session cookie was set and that the send stub never ran.
+import { test } from 'node:test';
+import assert from 'node:assert/strict';
+import { request } from 'node:http';
+import { spawn, spawnSync } from 'node:child_process';
+import { chmodSync, mkdirSync, mkdtempSync, rmSync, symlinkSync, writeFileSync } from 'node:fs';
+import { tmpdir } from 'node:os';
+import { join } from 'node:path';
+import { fileURLToPath } from 'node:url';
+import { startServer } from '../src/serve.mjs';
+import { createSso, readSlot, SESSION_COOKIE, LOGIN_COOKIE } from '../src/sso.mjs';
+import { close } from './fixture.mjs';
+import { b64url, ecKey, fakeOidc, jwt, psKey, rsaKey } from './helpers/fake-oidc.mjs';
+
+const HOST = 'console.example.test', ORIGIN = `https://${HOST}`;
+const CLI = fileURLToPath(new URL('../src/cli.mjs', import.meta.url));
+const MSG = JSON.stringify({ to: 'coder', body: 'Please look at row 192.' });
+// Test 19: every log line any test here captured, and every token, code, state, nonce, verifier,
+// client secret and session id any test produced. The last test checks the one against the other.
+const ALL_LINES = [], PRODUCED = new Set();
+
+// node:http, not fetch: fetch can't set Host, Origin or Sec-Fetch-Site.
+function call(port, { method = 'GET', path = '/', headers = {}, body, host = HOST } = {}) {
+  return new Promise((resolve, reject) => {
+    const length = body === undefined ? {} : { 'content-length': Buffer.byteLength(body) };
+    const req = request({ host: '127.0.0.1', port, method, path, headers: { host, ...length, ...headers } }, res => {
+      let text = '';
+      res.on('data', c => (text += c));
+      res.on('end', () => resolve({ status: res.statusCode, headers: res.headers, body: text && (res.headers['content-type'] ?? '').startsWith('application/json') ? JSON.parse(text) : text }));
+    });
+    req.on('error', reject);
+    req.end(body);
+  });
+}
+const setCookies = r => [r.headers['set-cookie'] ?? []].flat();
+const sessionOf = r => setCookies(r).find(c => c.startsWith(`${SESSION_COOKIE}=`) && !c.includes('Max-Age=0'))?.split(';')[0] ?? null;
+const writeHeaders = cookie => ({ ...(cookie ? { cookie } : {}), origin: ORIGIN, 'sec-fetch-site': 'same-origin', 'content-type': 'application/json' });
+
+function providerFor(iss, extra = {}) {
+  return { id: iss.name, issuer: iss.issuer, clientId: iss.clientId, clientSecret: { slot: iss.name }, algs: [...new Set(iss.keys.map(k => k.alg))], subjects: [{ sub: `user-${iss.name}`, name: `person-${iss.name}` }], ...extra };
+}
+
+// A fake OP with `issuers`, createSso over them, and the human listener with a counting send.
+async function setup(t, { issuers = [{ name: 'a' }], provider = {}, before = null, retryFirst = 5000, server = {} } = {}) {
+  const op = await fakeOidc();
+  t.after(() => op.close());
+  const iss = issuers.map(o => op.issuer(o.name, o));
+  for (const i of iss) PRODUCED.add(i.clientSecret);
+  before?.(op, iss);
+  const config = { publicOrigin: ORIGIN, providers: iss.map(i => providerFor(i, provider[i.name] ?? {})) };
+  const lines = [];
+  const log = line => { lines.push(line); ALL_LINES.push(line); };
+  const sso = await createSso(config, { secrets: new Map(iss.map(i => [i.name, i.clientSecret])), fetch: op.fetch, log, retryFirst });
+  t.after(() => sso.close());
+  const sends = [];
+  const bus = Object.fromEntries(['inbox', 'tasks', 'agents', 'trail', 'decisions'].map(v => [v, async () => [{ verb: v }]]));
+  const web = await startServer({ port: 0, board: 'http://127.0.0.1:9', bus, sso, send: async args => { sends.push(args); return { id: 'msg-0001' }; }, log, ...server });
+  t.after(() => close(web));
+  return { op, iss, sso, port: web.address().port, lines, sends, config, bus };
+}
+
+// GET /auth/login; returns the authorize URL and the login cookie (name=value).
+async function begin(env, { provider = null, ret = null, query = null, host = HOST } = {}) {
+  const q = query ?? new URLSearchParams({ ...(provider ? { provider } : {}), ...(ret !== null ? { return: ret } : {}) }).toString();
+  const r = await call(env.port, { path: `/auth/login${q ? `?${q}` : ''}`, host });
+  assert.equal(r.status, 303, `login start: ${r.status} ${r.body}`);
+  const cookie = setCookies(r)[0].split(';')[0];
+  const location = r.headers.location;
+  const params = new URL(location).searchParams;
+  PRODUCED.add(cookie.split('=')[1]);
+  for (const k of ['state', 'nonce', 'code_challenge']) PRODUCED.add(params.get(k));
+  for (const record of env.sso.logins.values()) PRODUCED.add(record.verifier);
+  return { r, cookie, location, params };
+}
+function callback(env, begun, { code, state = begun.params.get('state'), extra = {}, cookie = begun.cookie } = {}) {
+  const q = new URLSearchParams({ ...(code !== undefined ? { code } : {}), state, ...extra });
+  return call(env.port, { path: `/auth/callback?${q}`, headers: cookie ? { cookie } : {} });
+}
+function grant(env, begun, iss, opts = {}) {
+  const g = env.op.grant(iss, begun.location, opts);
+  PRODUCED.add(g.code);
+  PRODUCED.add(g.idToken);
+  return g;
+}
+// A whole sign-in: start, a code at the OP, the callback. Returns the callback answer and the
+// session cookie (name=value) when one was set.
+async function signIn(env, { iss = env.iss[0], ret = null, opts = {} } = {}) {
+  const begun = await begin(env, { provider: env.iss.length > 1 ? iss.name : null, ret });
+  const g = grant(env, begun, iss, opts);
+  const r = await callback(env, begun, { code: g.code });
+  const session = sessionOf(r);
+  if (session) PRODUCED.add(session.split('=')[1]);
+  return { begun, g, r, session };
+}
+function refused(env, r, code) {
+  assert.equal(r.status, 403, `expected 403, got ${r.status}`);
+  assert.equal(sessionOf(r), null, 'a session cookie was set');
+  assert.equal(env.sends.length, 0, 'the send stub ran');
+  assert.ok(setCookies(r).includes(`${LOGIN_COOKIE}=; Path=/; Secure; HttpOnly; SameSite=Lax; Max-Age=0`), 'the login cookie was not expired');
+  if (code) assert.match(env.lines.at(-1), new RegExp(` sso refused code=${code} provider=`), env.lines.at(-1));
+}
+
+test('positive: an RS256 provider signs in and sends one message, and the session reads', async t => {
+  const env = await setup(t);
+  assert.notEqual(env.port, 7332);
+  const { r, session } = await signIn(env, { ret: '/board?x=1' });
+  assert.equal(r.status, 303);
+  assert.equal(r.headers.location, `${ORIGIN}/board?x=1`);
+  assert.ok(session);
+  const send = await call(env.port, { method: 'POST', path: '/api/bus/message', headers: writeHeaders(session), body: MSG });
+  assert.equal(send.status, 200, JSON.stringify(send.body));
+  assert.deepEqual(env.sends, [{ to: 'coder', body: 'Please look at row 192.' }]);
+  assert.match(env.lines.at(-1), / send user="person-a" to="coder" id=msg-0001$/);
+  const read = await call(env.port, { path: '/api/bus/inbox', headers: { cookie: session } });
+  assert.equal(read.status, 200);
+  const config = await call(env.port, { path: '/api/config', headers: { cookie: session } });
+  assert.equal(config.body.sso, true);
+  assert.equal(config.body.send, true);
+});
+
+test('positive: an ES256 provider signs in and sends', async t => {
+  const env = await setup(t, { issuers: [{ name: 'e', keys: [ecKey()] }] });
+  assert.deepEqual(env.config.providers[0].algs, ['ES256']);
+  const { session } = await signIn(env);
+  assert.ok(session);
+  assert.equal((await call(env.port, { method: 'POST', path: '/api/bus/message', headers: writeHeaders(session), body: MSG })).status, 200);
+  assert.equal(env.sends.length, 1);
+});
+
+test('positive: two providers each sign in their own subjects, and one provider\'s subject is unknown to the other', async t => {
+  const env = await setup(t, { issuers: [{ name: 'a' }, { name: 'b', keys: [ecKey()] }] });
+  const list = await call(env.port, { path: '/auth/login?return=%2Fboard' });
+  assert.equal(list.status, 200);
+  assert.match(list.body, /provider=a&#38;return=%2Fboard/);
+  assert.match(list.body, /provider=b&#38;return=%2Fboard/);
+  const [a, b] = env.iss;
+  assert.ok((await signIn(env, { iss: a })).session);
+  assert.ok((await signIn(env, { iss: b })).session);
+  const names = [...env.sso.sessions.values()].map(s => s.name);
+  assert.deepEqual(names, ['person-a', 'person-b']);
+  const cross = await signIn(env, { iss: b, opts: { sub: 'user-a' } });
+  refused({ ...env, sends: [] }, cross.r, 'subject-unknown');
+});
+
+test('1: a forged x-authentik header without a cookie is 401 on the API and a sign-in redirect on a page', async t => {
+  const env = await setup(t);
+  const forged = { 'x-authentik-username': 'jason.woltje', origin: ORIGIN, 'sec-fetch-site': 'same-origin', 'content-type': 'application/json' };
+  for (const [method, path, body] of [['POST', '/api/bus/message', MSG], ['POST', '/api/settings', '{}'], ['GET', '/api/config', undefined]]) {
+    const r = await call(env.port, { method, path, headers: forged, body });
+    assert.equal(r.status, 401, `${method} ${path}`);
+    assert.deepEqual(r.body, { error: 'sign-in required' });
+  }
+  const page = await call(env.port, { path: '/', headers: forged });
+  assert.equal(page.status, 303);
+  assert.equal(page.headers.location, '/auth/login?return=%2F');
+  const deep = await call(env.port, { path: '/board?x=1' });
+  assert.equal(deep.headers.location, '/auth/login?return=%2Fboard%3Fx%3D1');
+  assert.equal(env.sends.length, 0);
+});
+
+test('2: an HS256 ID token keyed with the client secret and a real RSA kid is refused', async t => {
+  const env = await setup(t);
+  const [iss] = env.iss;
+  const { r } = await signIn(env, { opts: { header: { alg: 'HS256', kid: iss.keys[0].kid } } });
+  refused(env, r, 'id-token-invalid');
+});
+
+test('3: a wrong aud, and an aud list holding another client with no azp, are refused', async t => {
+  const env = await setup(t);
+  refused(env, (await signIn(env, { opts: { claims: { aud: 'another-client' } } })).r, 'id-token-invalid');
+  refused(env, (await signIn(env, { opts: { claims: { aud: [env.iss[0].clientId, 'another-client'] } } })).r, 'id-token-invalid');
+});
+
+test('4: a token that expired 10 minutes ago is refused', async t => {
+  const env = await setup(t);
+  const now = Math.floor(Date.now() / 1000);
+  refused(env, (await signIn(env, { opts: { claims: { iat: now - 900, exp: now - 600 } } })).r, 'id-token-invalid');
+});
+
+test('5: another issuer, and the issuer without its trailing slash, are refused', async t => {
+  const env = await setup(t);
+  const [iss] = env.iss;
+  refused(env, (await signIn(env, { opts: { claims: { iss: `${env.op.base}/other/` } } })).r, 'id-token-invalid');
+  refused(env, (await signIn(env, { opts: { claims: { iss: iss.issuer.slice(0, -1) } } })).r, 'id-token-invalid');
+});
+
+test('6: a nonce mismatch and a missing nonce are refused', async t => {
+  const env = await setup(t);
+  refused(env, (await signIn(env, { opts: { claims: { nonce: 'not-the-nonce' } } })).r, 'id-token-invalid');
+  refused(env, (await signIn(env, { opts: { claims: { nonce: undefined } } })).r, 'id-token-invalid');
+});
+
+test('7: state mismatch, no login cookie, a replay, an expired record and two login cookies are refused', async t => {
+  const env = await setup(t);
+  const [iss] = env.iss;
+  let begun = await begin(env);
+  refused(env, await callback(env, begun, { code: grant(env, begun, iss).code, state: 'wrong-state' }), 'state-mismatch');
+  begun = await begin(env);
+  refused(env, await callback(env, begun, { code: grant(env, begun, iss).code, cookie: null }), 'login-record-missing');
+  // Replay: the OP takes the code twice, so only the take-and-delete rule refuses the second callback.
+  iss.acceptTwice = true;
+  begun = await begin(env);
+  const g = grant(env, begun, iss);
+  const first = await callback(env, begun, { code: g.code });
+  assert.equal(first.status, 303);
+  PRODUCED.add(sessionOf(first).split('=')[1]);
+  refused(env, await callback(env, begun, { code: g.code }), 'login-record-missing');
+  iss.acceptTwice = false;
+  begun = await begin(env);
+  for (const record of env.sso.logins.values()) record.expires = Date.now() - 1;
+  refused(env, await callback(env, begun, { code: grant(env, begun, iss).code }), 'login-record-missing');
+  begun = await begin(env);
+  const other = await begin(env);
+  refused(env, await callback(env, begun, { code: grant(env, begun, iss).code, cookie: `${begun.cookie}; ${other.cookie}` }), 'login-record-missing');
+});
+
+test('8: the token request carries the PKCE verifier, and the OP refuses a wrong one', async t => {
+  const env = await setup(t);
+  const [iss] = env.iss;
+  const { r, begun } = await signIn(env);
+  assert.equal(r.status, 303);
+  const { form } = iss.tokenRequests.at(-1);
+  assert.equal(begun.params.get('code_challenge_method'), 'S256');
+  const { createHash } = await import('node:crypto');
+  assert.equal(createHash('sha256').update(form.code_verifier).digest('base64url'), begun.params.get('code_challenge'));
+  refused(env, (await signIn(env, { opts: { challenge: 'not-the-challenge' } })).r, 'grant-failed');
+});
+
+test('9: alg none, a changed payload under a real kid, and an unknown kid even after the refetch are refused', async t => {
+  const env = await setup(t);
+  const [iss] = env.iss;
+  // (a) alg none: the alg rule, before any signature check.
+  refused(env, (await signIn(env, { opts: { header: { alg: 'none' } } })).r, 'id-token-invalid');
+  // (b) a real kid's signature over another payload: only the signature check catches it.
+  let begun = await begin(env);
+  const real = env.op.grant(iss, begun.location);
+  PRODUCED.add(real.idToken);
+  const [h, , s] = real.idToken.split('.');
+  const forged = `${h}.${b64url({ ...real.payload, name: 'changed' })}.${s}`;
+  refused(env, await callback(env, begun, { code: grant(env, begun, iss, { idToken: forged }).code }), 'signature-invalid');
+  // (c) a key the JWKS never held, again after the cache is old enough to refetch.
+  t.mock.timers.enable({ apis: ['Date'], now: Date.now() });
+  const stranger = rsaKey('not-in-jwks');
+  refused(env, (await signIn(env, { opts: { key: stranger } })).r, 'signature-invalid');
+  const fetches = iss.jwksFetches;
+  t.mock.timers.tick(61000);
+  refused(env, (await signIn(env, { opts: { key: stranger } })).r, 'signature-invalid');
+  assert.equal(iss.jwksFetches, fetches + 1, 'no refetch');
+});
+
+test('10: a valid token for a subject not configured is 403 with one subject-unknown line', async t => {
+  const env = await setup(t);
+  const before = env.lines.length;
+  const { r } = await signIn(env, { opts: { sub: 'stranger' } });
+  refused(env, r, 'subject-unknown');
+  const added = env.lines.slice(before);
+  assert.equal(added.length, 1);
+  assert.match(added[0], new RegExp(`^\\S+ sso refused code=subject-unknown provider=a iss=${JSON.stringify(env.iss[0].issuer).replace(/[.*+?^${}()|[\]\\/]/g, '\\$&')} sub="stranger"$`));
+});
+
+test('11: start refusals: HS or none algs, reserved names, HS-only discovery, an empty JWKS, no S256, an issuer mismatch, a short RSA key', async t => {
+  const op = await fakeOidc();
+  t.after(() => op.close());
+  const start = (iss, extra = {}) => createSso({ publicOrigin: ORIGIN, providers: [providerFor(iss, extra)] }, { secrets: new Map([[iss.name, iss.clientSecret]]), fetch: op.fetch, log: l => ALL_LINES.push(l) });
+  const a = op.issuer('a');
+  PRODUCED.add(a.clientSecret);
+  for (const [extra, why] of [
+    [{ algs: ['HS256'] }, /algs\[0\] must be one of .*HS\* and none are refused/],
+    [{ algs: ['none'] }, /algs\[0\] must be one of/],
+    [{ subjects: [{ sub: 'u', name: 'tester' }] }, /subjects\[0\]\.name must not be tester or human/],
+    [{ subjects: [{ sub: 'u', name: 'Human' }] }, /subjects\[0\]\.name must not be tester or human/],
+  ]) await assert.rejects(start(a, extra), why);
+  const refusedAtDiscovery = /console\.sso provider \w+ refused at discovery/;
+  // The mosaic-preview shape: HS256 only.
+  const hs = op.issuer('hs', { discovery: { id_token_signing_alg_values_supported: ['HS256'] } });
+  await assert.rejects(start(hs, { algs: ['RS256'] }), refusedAtDiscovery);
+  const empty = op.issuer('empty');
+  empty.jwksOverride = { keys: [] };
+  await assert.rejects(start(empty), refusedAtDiscovery);
+  const plain = op.issuer('plain', { discovery: { code_challenge_methods_supported: ['plain'] } });
+  await assert.rejects(start(plain), refusedAtDiscovery);
+  const moved = op.issuer('moved');
+  moved.discovery = { issuer: `${op.base}/elsewhere/` };
+  await assert.rejects(start(moved), refusedAtDiscovery);
+  const small = op.issuer('small', { keys: [rsaKey('small', 1024)] });
+  await assert.rejects(start(small), refusedAtDiscovery);
+  // The control: the same OP and provider start.
+  const sso = await start(a);
+  assert.deepEqual(sso.health(), { a: 'ready' });
+  sso.close();
+  await assert.rejects(startServer({ port: 0, sso, preview: { host: HOST, header: 'remote-user', user: 'jason' } }), /--sso cannot be combined/);
+});
+
+test('11: slot files: a symlink, mode 0644, mode 0640 and a file under the repository are refused, and no message holds the value', t => {
+  const root = mkdtempSync(join(tmpdir(), 'webui-sso-slot-'));
+  t.after(() => rmSync(root, { recursive: true, force: true }));
+  const dir = join(root, 'config'), slots = join(dir, 'secrets', 'mosaic-stack');
+  mkdirSync(slots, { recursive: true });
+  const provider = slot => ({ id: 'a', clientSecret: { slot } });
+  const value = 'slot-value-do-not-print';
+  const opts = { repo: join(root, 'repo'), copies: join(root, 'copies') };
+  writeFileSync(join(slots, 'good'), `${value}\n`, { mode: 0o600 });
+  assert.equal(readSlot(dir, provider('good'), opts), value);
+  writeFileSync(join(root, 'target'), value, { mode: 0o600 });
+  symlinkSync(join(root, 'target'), join(slots, 'link'));
+  for (const [slot, mode] of [['wide', 0o644], ['group', 0o640]]) { writeFileSync(join(slots, slot), value); chmodSync(join(slots, slot), mode); }
+  writeFileSync(join(slots, 'two'), `${value}\nmore\n`, { mode: 0o600 });
+  writeFileSync(join(slots, 'empty'), '\n', { mode: 0o600 });
+  const cases = [
+    ['missing', /slot is missing$/, opts],
+    ['link', /must not be a symbolic link$/, opts],
+    ['wide', /must have no group or other permission bits$/, opts],
+    ['group', /must have no group or other permission bits$/, opts],
+    ['two', /must hold one non-empty line$/, opts],
+    ['empty', /must hold one non-empty line$/, opts],
+    // The config dir itself under the repository, and under a --checkout.
+    ['good', /must not be inside the repository or a stack copy$/, { ...opts, repo: root }],
+    ['good', /must not be inside the repository or a stack copy$/, { ...opts, checkout: dir }],
+    ['good', /must not be inside the repository or a stack copy$/, { ...opts, copies: dir }],
+  ];
+  for (const [slot, why, o] of cases) {
+    let err = null;
+    try { readSlot(dir, provider(slot), o); } catch (e) { err = e; }
+    assert.ok(err, `${slot} was read`);
+    assert.match(err.message, /^console\.sso provider a client secret slot /);
+    assert.match(err.message, why, slot);
+    assert.equal(err.message.includes(value), false);
+    assert.equal(err.message.includes(root), false);
+  }
+});
+
+test('11: the CLI refuses --sso with the old flags and without console.sso, and starts with a good one', async t => {
+  const root = mkdtempSync(join(tmpdir(), 'wsso-'));
+  t.after(() => rmSync(root, { recursive: true, force: true }));
+  const env = { ...process.env, MOSAIC_CONFIG: join(root, 'cfg', 'config.json'), XDG_DATA_HOME: join(root, 'xdg') };
+  for (const flags of [['--auth-header', 'remote-user'], ['--public-host', HOST], ['--allow-user', 'jason'], ['--proof-header', 'x-proof']]) {
+    const r = spawnSync(process.execPath, [CLI, 'serve', '--port', '0', '--sso', ...flags], { encoding: 'utf8', timeout: 10000, env });
+    assert.equal(r.status, 2, flags.join(' '));
+    assert.match(r.stderr, /^refused: --sso cannot be combined with --public-host, --auth-header, --allow-user or --proof-\*$/m);
+  }
+  const missing = spawnSync(process.execPath, [CLI, 'serve', '--port', '0', '--sso'], { encoding: 'utf8', timeout: 10000, env });
+  assert.equal(missing.status, 2);
+  assert.match(missing.stderr, /^refused: --sso needs the system config \(/);
+  const op = await fakeOidc();
+  t.after(() => op.close());
+  const a = op.issuer('a');
+  PRODUCED.add(a.clientSecret);
+  mkdirSync(join(root, 'cfg', 'secrets', 'mosaic-stack'), { recursive: true });
+  writeFileSync(join(root, 'ca.pem'), op.cert);
+  const base = { configVersion: 1, environment: 'development', dataRoot: join(root, 'data'), execution: { backend: 'docker', provider: 'zai', model: 'm' } };
+  writeFileSync(env.MOSAIC_CONFIG, JSON.stringify(base));
+  const noKey = spawnSync(process.execPath, [CLI, 'serve', '--port', '0', '--sso'], { encoding: 'utf8', timeout: 10000, env });
+  assert.equal(noKey.status, 2);
+  assert.match(noKey.stderr, /^refused: --sso needs console\.sso in the system config$/m);
+  writeFileSync(env.MOSAIC_CONFIG, JSON.stringify({ ...base, console: { sso: { publicOrigin: ORIGIN, providers: [providerFor(a)] } } }));
+  writeFileSync(join(root, 'cfg', 'secrets', 'mosaic-stack', 'a'), `${a.clientSecret}\n`, { mode: 0o644 });
+  const wide = spawnSync(process.execPath, [CLI, 'serve', '--port', '0', '--sso'], { encoding: 'utf8', timeout: 10000, env });
+  assert.equal(wide.status, 2);
+  assert.match(wide.stderr, /^refused: console\.sso provider a client secret slot must have no group or other permission bits$/m);
+  chmodSync(join(root, 'cfg', 'secrets', 'mosaic-stack', 'a'), 0o600);
+  // The child trusts the fake OP's certificate through NODE_EXTRA_CA_CERTS; the code under test has no flag for it.
+  const child = spawn(process.execPath, [CLI, 'serve', '--port', '0', '--sso'], { env: { ...env, NODE_EXTRA_CA_CERTS: join(root, 'ca.pem') } });
+  t.after(() => child.kill('SIGKILL'));
+  let out = '', err = '';
+  child.stderr.on('data', c => (err += c));
+  await new Promise((resolve, reject) => {
+    const timer = setTimeout(() => reject(new Error(`no start line: ${out} ${err}`)), 15000);
+    child.stdout.on('data', c => { out += c; if (out.includes('Ctrl-C')) { clearTimeout(timer); resolve(); } });
+    child.on('exit', () => { clearTimeout(timer); reject(new Error(`exited: ${err}`)); });
+  });
+  assert.match(out, new RegExp(`^Sign-in: ${ORIGIN}/ \\(--sso\\), read-only$`, 'm'));
+  assert.match(out, new RegExp(`^Sign-in provider: a issuer ${a.issuer.replace(/[.]/g, '\\.')} subjects 1 \\(ready\\)$`, 'm'));
+  assert.equal(out.includes(a.clientSecret) || err.includes(a.clientSecret), false);
+  assert.equal(out.includes(a.clientId), false);
+  const port = Number(out.match(/^Mosaic Console: http:\/\/127\.0\.0\.1:(\d+)\//m)[1]);
+  const health = await call(port, { path: '/healthz', host: `127.0.0.1:${port}` });
+  assert.deepEqual(health.body, { ok: true, sso: { a: 'ready' } });
+  child.kill('SIGTERM');
+});
+
+test('12: under --sso the tester listener refuses each kind of sign-in, has no /auth, and startServer refuses tester with sso', async t => {
+  const env = await setup(t);
+  const tester = await startServer({ port: 0, board: 'http://127.0.0.1:9', bus: env.bus, tester: true, testerNoSignIn: true, log: () => {} });
+  t.after(() => close(tester));
+  const port = tester.address().port, host = `127.0.0.1:${port}`;
+  const { session, g, begun } = await signIn(env);
+  assert.ok(session);
+  const plain = await call(port, { path: '/api/config', host });
+  assert.equal(plain.status, 200, 'control: a request with no sign-in is served');
+  for (const headers of [
+    { cookie: session },
+    { cookie: `theme=dark; ${begun.cookie}` },
+    { cookie: `${SESSION_COOKIE.toLowerCase()}=x` },
+    { authorization: `Bearer ${g.idToken}` },
+    { 'x-authentik-jwt': g.idToken },
+    { 'X-Authentik-Username': 'jason.woltje' },
+  ]) {
+    const r = await call(port, { path: '/api/config', host, headers });
+    assert.equal(r.status, 403, JSON.stringify(Object.keys(headers)));
+    assert.deepEqual(r.body, { error: 'tester listener takes no sign-in' });
+  }
+  assert.equal((await call(port, { path: '/auth/login', host })).status, 404);
+  await assert.rejects(startServer({ port: 0, tester: true, sso: env.sso }), /tester listener cannot use sso/);
+});
+
+test('13: idle and absolute expiry, logout then reuse, a cross-origin logout, and background reads that don\'t keep a session', async t => {
+  const env = await setup(t);
+  const read = cookie => call(env.port, { path: '/api/bus/inbox', headers: { cookie } });
+  const record = () => [...env.sso.sessions.values()].at(-1);
+  // Background reads don't move `seen`; a page load does.
+  let { session } = await signIn(env);
+  const old = Date.now() - 59 * 60 * 1000;
+  record().seen = old;
+  assert.equal((await read(session)).status, 200);
+  assert.equal(record().seen, old, 'a background read refreshed the session');
+  assert.equal((await call(env.port, { path: '/', headers: { cookie: session } })).status, 200);
+  assert.ok(record().seen > old, 'a page load did not refresh the session');
+  // Idle: 59 minutes of background reads, then one more past the hour.
+  record().seen = Date.now() - 61 * 60 * 1000;
+  assert.equal((await read(session)).status, 401);
+  // Absolute.
+  ({ session } = await signIn(env));
+  record().created = Date.now() - 8 * 3600 * 1000;
+  assert.equal((await call(env.port, { path: '/', headers: { cookie: session } })).headers.location, '/auth/login?return=%2F');
+  // Logout needs same-origin; refused, the session stays.
+  ({ session } = await signIn(env));
+  const cross = await call(env.port, { method: 'POST', path: '/auth/logout', headers: { cookie: session, origin: ORIGIN, 'sec-fetch-site': 'cross-site' } });
+  assert.equal(cross.status, 403);
+  assert.equal((await read(session)).status, 200);
+  const noOrigin = await call(env.port, { method: 'POST', path: '/auth/logout', headers: { cookie: session, 'sec-fetch-site': 'same-origin' } });
+  assert.equal(noOrigin.status, 403);
+  assert.equal((await read(session)).status, 200);
+  const out = await call(env.port, { method: 'POST', path: '/auth/logout', headers: { cookie: session, origin: ORIGIN, 'sec-fetch-site': 'same-origin' } });
+  assert.equal(out.status, 303);
+  const end = new URL(out.headers.location);
+  assert.equal(`${end.origin}${end.pathname}`, `${env.iss[0].issuer}end-session`);
+  assert.equal(end.searchParams.get('post_logout_redirect_uri'), `${ORIGIN}/auth/signed-out`);
+  assert.equal(end.searchParams.get('client_id'), env.iss[0].clientId);
+  assert.ok(end.searchParams.get('id_token_hint'));
+  assert.deepEqual(setCookies(out), [`${SESSION_COOKIE}=; Path=/; Secure; HttpOnly; SameSite=Lax; Max-Age=0`]);
+  assert.equal((await read(session)).status, 401);
+  assert.equal((await call(env.port, { method: 'GET', path: '/auth/logout', headers: { cookie: session } })).status, 405);
+});
+
+test('13: the CSP lets the Sign out form reach the provider\'s end-session origin, and only under --sso', async t => {
+  const env = await setup(t);
+  const r = await call(env.port, { path: '/healthz', host: `127.0.0.1:${env.port}` });
+  assert.match(r.headers['content-security-policy'], new RegExp(`; form-action 'self' ${env.op.base.replace(/[.]/g, '\\.')}$`));
+  const plain = await startServer({ port: 0, board: 'http://127.0.0.1:9' });
+  t.after(() => close(plain));
+  const p = await call(plain.address().port, { path: '/healthz', host: `127.0.0.1:${plain.address().port}` });
+  assert.match(p.headers['content-security-policy'], /; form-action 'self'$/);
+});
+
+test('14: open redirects land on /, and a path on the Console lands there', async t => {
+  const env = await setup(t);
+  for (const [query, where] of [
+    ['return=%2F%2Fevil.example', `${ORIGIN}/`],
+    ['return=https%3A%2F%2Fevil.example', `${ORIGIN}/`],
+    ['return=%2F%5Cevil.example', `${ORIGIN}/`],
+    ['return=/%09/evil.example', `${ORIGIN}/`],
+    // Dot segments that leave a pathname of //evil.example stay on the Console (webby-0019 B1).
+    ['return=%2F.%2F%2Fevil.example', `${ORIGIN}//evil.example`],
+    ['return=%2Fx%2F..%2F%2Fevil.example', `${ORIGIN}//evil.example`],
+    [`return=${encodeURIComponent(`${ORIGIN}//evil.example`)}`, `${ORIGIN}//evil.example`],
+    ['return=%2Fboard%2F.%2Fx', `${ORIGIN}/board/x`],
+    ['return=%2Fboard%3Fx%3D1', `${ORIGIN}/board?x=1`],
+    ['', `${ORIGIN}/`],
+  ]) {
+    const begun = await begin(env, { query });
+    const r = await callback(env, begun, { code: grant(env, begun, env.iss[0]).code });
+    assert.equal(r.status, 303);
+    assert.equal(r.headers.location, where, query);
+    assert.equal(new URL(r.headers.location).origin, ORIGIN, query);
+    PRODUCED.add(sessionOf(r).split('=')[1]);
+  }
+});
+
+test('15: a callback for A carrying B\'s code and iss, and a provider= query, is refused', async t => {
+  const env = await setup(t, { issuers: [{ name: 'a' }, { name: 'b' }] });
+  const [, b] = env.iss;
+  for (const extra of [{ iss: b.issuer, provider: 'b' }, { provider: 'b' }]) {
+    const begun = await begin(env, { provider: 'a' });
+    // B's code against A's PKCE challenge and nonce, for B's own subject: only the record rule
+    // (this callback belongs to A) stands in the way.
+    const g = grant(env, begun, b, { sub: 'user-b' });
+    const r = await callback(env, begun, { code: g.code, extra });
+    refused(env, r);
+  }
+  assert.equal(b.tokenRequests.length, 0, 'B\'s token endpoint was called');
+});
+
+test('16: a provider with RS256 and ES256 takes either, and refuses PS256 with a usable PS256 key in the JWKS', async t => {
+  const rsa = rsaKey(), ec = ecKey(), ps = psKey();
+  const env = await setup(t, { issuers: [{ name: 'a', keys: [rsa, ec, ps] }], provider: { a: { algs: ['RS256', 'ES256'] } } });
+  assert.ok((await signIn(env, { opts: { key: rsa } })).session);
+  assert.ok((await signIn(env, { opts: { key: ec } })).session);
+  refused(env, (await signIn(env, { opts: { key: ps } })).r, 'id-token-invalid');
+});
+
+test('17: 33 started logins leave 32 records, and the first one\'s callback finds none', async t => {
+  const env = await setup(t);
+  const first = await begin(env);
+  for (let i = 0; i < 32; i++) await begin(env);
+  assert.equal(env.sso.logins.size, 32);
+  refused(env, await callback(env, first, { code: grant(env, first, env.iss[0]).code }), 'login-record-missing');
+});
+
+test('18: after a key rotation a sign-in works through one refetch, and the removed kid is refused', async t => {
+  const env = await setup(t);
+  const [iss] = env.iss;
+  t.mock.timers.enable({ apis: ['Date'], now: Date.now() });
+  const old = iss.keys[0];
+  assert.ok((await signIn(env)).session);
+  const fetches = iss.jwksFetches;
+  env.op.rotate(iss);
+  t.mock.timers.tick(61000);
+  assert.ok((await signIn(env)).session);
+  assert.equal(iss.jwksFetches, fetches + 1);
+  refused(env, (await signIn(env, { opts: { key: old } })).r, 'signature-invalid');
+});
+
+test('20 and 21: the store holds no raw session id, and the cookie strings are exact', async t => {
+  const env = await setup(t);
+  const begun = await begin(env);
+  assert.match(setCookies(begun.r)[0], new RegExp(`^${LOGIN_COOKIE}=[A-Za-z0-9_-]{43}; Path=/; Secure; HttpOnly; SameSite=Lax; Max-Age=600$`));
+  for (const key of env.sso.logins.keys()) assert.match(key, /^[0-9a-f]{64}$/);
+  const r = await callback(env, begun, { code: grant(env, begun, env.iss[0]).code });
+  const set = setCookies(r);
+  assert.equal(set.length, 2);
+  assert.equal(set[0], `${LOGIN_COOKIE}=; Path=/; Secure; HttpOnly; SameSite=Lax; Max-Age=0`);
+  assert.match(set[1], new RegExp(`^${SESSION_COOKIE}=[A-Za-z0-9_-]{43}; Path=/; Secure; HttpOnly; SameSite=Lax$`));
+  const id = set[1].split(';')[0].split('=')[1];
+  PRODUCED.add(id);
+  for (const [key, value] of env.sso.sessions) {
+    assert.match(key, /^[0-9a-f]{64}$/);
+    assert.notEqual(key, id);
+    assert.equal(JSON.stringify(value).includes(id), false);
+  }
+});
+
+test('22: a loopback Host is 403 on a page, a read and a write; /healthz on loopback is 200; a redirect_uri never comes from the Host', async t => {
+  const env = await setup(t);
+  const { session } = await signIn(env);
+  const loop = `127.0.0.1:${env.port}`;
+  for (const [method, path, body] of [['GET', '/', undefined], ['GET', '/api/board', undefined], ['GET', '/api/bus/inbox', undefined], ['POST', '/api/bus/message', MSG]]) {
+    // A loopback Host on this listener's port; any other Host is already the older non-local refusal.
+    for (const host of [loop, `localhost:${env.port}`]) {
+      const r = await call(env.port, { method, path, host, body, headers: { cookie: session, 'content-type': 'application/json' } });
+      assert.equal(r.status, 403, `${method} ${path} ${host}`);
+      assert.deepEqual(r.body, { error: 'public Host required' });
+    }
+  }
+  const health = await call(env.port, { path: '/healthz', host: loop });
+  assert.equal(health.status, 200);
+  assert.deepEqual(health.body, { ok: true, sso: { a: 'ready' } });
+  assert.equal(env.sends.length, 0);
+  const begun = await begin(env, { host: HOST.toUpperCase() });
+  assert.equal(begun.params.get('redirect_uri'), `${ORIGIN}/auth/callback`);
+});
+
+test('23: a provider down at start leaves the Console up and 503, and the retry makes sign-in work', async t => {
+  let env = await setup(t, { retryFirst: 50, before: (op, [a]) => { a.mode = 'down'; } });
+  assert.equal((await call(env.port, { path: '/auth/login' })).status, 503);
+  assert.deepEqual((await call(env.port, { path: '/healthz', host: `127.0.0.1:${env.port}` })).body.sso, { a: 'unreachable' });
+  assert.match(env.lines.at(-1), / sso refused code=discovery-failed provider=a$/);
+  env.iss[0].mode = 'ok';
+  for (let i = 0; i < 100 && env.sso.health().a !== 'ready'; i++) await new Promise(r => setTimeout(r, 20));
+  assert.deepEqual(env.sso.health(), { a: 'ready' });
+  assert.ok((await signIn(env)).session);
+  // A 200 HTML page at the discovery URL is unreachable too, and the Console starts.
+  env = await setup(t, { before: (op, [a]) => { a.mode = 'html'; } });
+  assert.deepEqual(env.sso.health(), { a: 'unreachable' });
+  // HS-only discovery at start refuses the start.
+  await assert.rejects(setup(t, { before: (op, [a]) => { a.discovery = { id_token_signing_alg_values_supported: ['HS256'] }; } }), /refused at discovery/);
+});
+
+test('19: no captured log line holds a token, code, state, nonce, verifier, client secret or session id', () => {
+  assert.ok(ALL_LINES.length > 20, `only ${ALL_LINES.length} lines`);
+  assert.ok(PRODUCED.size > 50, `only ${PRODUCED.size} values`);
+  for (const line of ALL_LINES) {
+    for (const value of PRODUCED) if (value) assert.equal(line.includes(value), false, `a log line holds a produced value: ${line.slice(0, 80)}`);
+    assert.match(line, /^\S+ (sso refused code=[a-z-]+ provider=[a-z0-9-]+( iss="[^"]*" sub="[^"]*")?|send user="[^"]+" to="[^"]*" (id=msg-0001|error=[a-z -]+))$/, line);
+  }
+});
@@ -3,9 +3,11 @@
 #
 # Creates ~/.config/mosaic-dev/config.json (or $MOSAIC_CONFIG) only when
 # absent. An existing configuration is validated, never modified.
+# `--instance NAME` (row 190) creates ~/.config/mosaic-NAME/config.json
+# instead, with the data root ~/.mosaic-NAME claimed by its instance.json.
 # Normal run paths (build/hello/verify) deliberately do NOT auto-bootstrap:
 # missing configuration is an error there, not something to invent.
 set -euo pipefail
 cd "$(dirname "$0")/.."

-exec node scripts/mosaic-config.mjs bootstrap
+exec node scripts/mosaic-config.mjs bootstrap "$@"
@@ -19,12 +19,24 @@
 # (MOSAIC_CLAUDE_BIN); without it, `command -v claude` here. The path is
 # kept as given, so a symlink that tracks updates keeps tracking them.
 #
-# Exit codes: 0 ok, 1 operation failed, 4 usage.
+# --instance NAME (row 190, any position) selects stack instance NAME: the
+# unit is [email protected], it sets MOSAIC_CONFIG to
+# ~/.config/mosaic-NAME/config.json, and its session env file sits in that
+# config directory. Busy and drop-in checks then cover only NAME's bus units
+# and the prefix directories systemd applies to them. See scripts/instance.sh.
+#
+# Exit codes: 0 ok, 1 operation failed, 3 the data root is claimed by another
+# instance or not claimed (scripts/instance.sh), 4 usage.
 set -euo pipefail
 REPO="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
 TEMPLATE="$REPO/packages/cli/systemd/mosaic-bus.service.in"
-UNIT_NAME="[email protected]"
-USAGE="usage: scripts/bus-service.sh render [--copy ID [--copies DIR]] [--pm] [--claude PATH] | install [--copy ID [--copies DIR]] [--pm] [--dir DIR] [--no-reload] [--claude PATH] | uninstall [--dir DIR] [--no-reload] | status <business>"
+# shellcheck source=scripts/instance.sh
+. "$REPO/scripts/instance.sh"
+instance_args "$@"
+set -- ${INSTANCE_ARGS[@]+"${INSTANCE_ARGS[@]}"}
+instance_select
+UNIT_NAME="$BUS_TEMPLATE"
+USAGE="usage: scripts/bus-service.sh [--instance NAME] render [--copy ID [--copies DIR]] [--pm] [--claude PATH] | install [--copy ID [--copies DIR]] [--pm] [--dir DIR] [--no-reload] [--claude PATH] | uninstall [--dir DIR] [--no-reload] | status <business>"

 die() { echo "bus-service: $*" >&2; exit 1; }
 usage() { echo "$USAGE" >&2; exit 4; }
@@ -76,7 +88,7 @@ render() {
    case "$REPO" in *@*|*'|'*) die "repository path contains a character the template cannot carry: $REPO" ;; esac
    local claude
    claude="$(claude_line)" || exit 1
-    sed -e "s|@REPO@|$root|g" -e "s|@PATH@|$path|g" -e "s|@PM_FLAGS@|$pm_flags|g" -e "s|^@CLAUDE_ENV@$|$claude|" "$TEMPLATE"
+    sed -e "s|@REPO@|$root|g" -e "s|@PATH@|$path|g" -e "s|@PM_FLAGS@|$pm_flags|g" -e "s|^@CLAUDE_ENV@$|$claude|" "${INSTANCE_SED[@]}" "$TEMPLATE"
 }

 UNIT_DIR="${XDG_CONFIG_HOME:-$HOME/.config}/systemd/user"
@@ -99,9 +111,10 @@ parse_flags() {
 # Any failed read refuses before a write, including --no-reload installations.
 install_guard() {
    local out unit file
-    out="$(systemctl --user list-units --all --no-legend --plain 'mosaic-bus@*.service' 2>/dev/null)" || die "refusing: systemctl --user list-units failed, so the bus state is unknown; nothing was changed"
+    out="$(systemctl --user list-units --all --no-legend --plain "$BUS_GLOB" 2>/dev/null)" || die "refusing: systemctl --user list-units failed, so the bus state is unknown; nothing was changed"
    while read -r unit load state rest; do
-        [[ "$unit" == mosaic-bus@*.service ]] || continue
+        # shellcheck disable=SC2053
+        [[ "$unit" == $BUS_GLOB ]] || continue
        case "$state" in inactive|failed) ;; *) die "refusing: $unit is running ($state); Jason or Mos stops it first, then install, then start it" ;; esac
    done <<< "$out"
    # systemctl show rejects a template name. The lookup-path scan also
@@ -114,8 +127,12 @@ install_guard() {
        case "$directory" in /*) ;; *) die "refusing: invalid systemd unit path $directory; nothing was changed" ;; esac
        [ -e "$directory" ] || [ -L "$directory" ] || continue
        [ -d "$directory" ] && [ -r "$directory" ] && [ -x "$directory" ] || die "refusing: cannot inspect unit path $directory; nothing was changed"
-        # * includes the empty instance, i.e. [email protected].
-        for dropdir in "$directory"/mosaic-bus@*.service.d "$directory"/mosaic-.service.d "$directory"/service.d; do
+        # * includes the empty instance, i.e. [email protected] (or
+        # mosaic-bus-NAME@.service.d). The globs come from scripts/instance.sh.
+        local glob dropdirs=()
+        # shellcheck disable=SC2206
+        for glob in "${BUS_DROPIN_GLOBS[@]}"; do dropdirs+=("$directory"/$glob); done
+        for dropdir in "${dropdirs[@]}"; do
            [ -e "$dropdir" ] || [ -L "$dropdir" ] || continue
            [ -d "$dropdir" ] && [ -r "$dropdir" ] && [ -x "$dropdir" ] || die "refusing: cannot inspect drop-ins $dropdir; nothing was changed"
            for file in "$dropdir"/*.conf; do
@@ -161,10 +178,10 @@ next, for one business (one per data root):
  mkdir -m 0700 -p <dataRoot>/notify/<business>               the notifier refuses a looser directory
  write <dataRoot>/notify/<business>/notify.json, mode 0600:
    {"notifyVersion": 1, "binding": "<discord binding>"}   or "binding": null for no DMs
-  systemctl --user enable --now mosaic-bus@<business>      start now and at login
-  systemctl --user status mosaic-bus@<business>
-  journalctl --user -u mosaic-bus@<business> -f             the host's log
-  systemctl --user stop mosaic-bus@<business>               SIGTERM; restartable
+  systemctl --user enable --now ${BUS_TEMPLATE%.service}<business>      start now and at login
+  systemctl --user status ${BUS_TEMPLATE%.service}<business>
+  journalctl --user -u ${BUS_TEMPLATE%.service}<business> -f             the host's log
+  systemctl --user stop ${BUS_TEMPLATE%.service}<business>               SIGTERM; restartable
 survive logout and reboot only with lingering on: loginctl enable-linger ${USER:-$(id -un)}
 MSG
 }
@@ -174,7 +191,7 @@ uninstall_unit() {
    [ "$CLAUDE_SET" = 0 ] && [ -z "$COPY_ID" ] && [ "$PM" = 0 ] || usage
    local target="$UNIT_DIR/$UNIT_NAME"
    local out active
-    out="$(systemctl --user list-units --all --no-legend --plain 'mosaic-bus@*.service' 2>/dev/null)" || die "refusing: systemctl read failed; nothing was changed"
+    out="$(systemctl --user list-units --all --no-legend --plain "$BUS_GLOB" 2>/dev/null)" || die "refusing: systemctl read failed; nothing was changed"
    active="$(awk '$3 != "inactive" && $3 != "failed" {print $1}' <<< "$out")"
    [ -z "$active" ] || die "refusing: instance(s) still running: $active; Jason or Mos stops them first"
    if [ -f "$target" ]; then
@@ -193,7 +210,7 @@ status_unit() {
    [ $# -eq 1 ] || usage
    local business="$1"
    case "$business" in ''|*[!a-z0-9-]*) die "business id must be [a-z0-9-]+" ;; esac
-    local unit="mosaic-bus@$business.service"
+    local unit="${BUS_TEMPLATE%.service}$business.service"
    echo "unit: $unit"
    echo "  enabled: $(systemctl --user is-enabled "$unit" 2>&1 || true)"
    echo "  active:  $(systemctl --user is-active "$unit" 2>&1 || true)"
@@ -14,12 +14,21 @@
 #                                remove the unit; refuses while an instance is active
 #   status <binding>             unit state, STOP and run.lock for one binding
 #
-# Exit codes: 0 ok, 1 operation failed, 4 usage.
+# Every verb takes --instance NAME (row 190, scripts/instance.sh): the unit is
+# then [email protected], it sets NAME's MOSAIC_CONFIG, and status
+# reads NAME's config. Without it, everything is as before.
+#
+# Exit codes: 0 ok, 1 operation failed, 3 instance claim refused, 4 usage.
 set -euo pipefail
 REPO="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
 TEMPLATE="$REPO/packages/discord/systemd/[email protected]"
-UNIT_NAME="[email protected]"
-USAGE="usage: scripts/discord-service.sh render [--copy ID [--copies DIR]] | install [--copy ID [--copies DIR]] [--dir DIR] [--no-reload] | uninstall [--dir DIR] [--no-reload] | status <binding>"
+. "$REPO/scripts/instance.sh"
+instance_args "$@"
+set -- ${INSTANCE_ARGS[@]+"${INSTANCE_ARGS[@]}"}
+instance_select
+UNIT_NAME="$DISCORD_TEMPLATE"
+UNIT_PREFIX="${DISCORD_TEMPLATE%.service}"
+USAGE="usage: scripts/discord-service.sh [--instance NAME] render [--copy ID [--copies DIR]] | install [--copy ID [--copies DIR]] [--dir DIR] [--no-reload] | uninstall [--dir DIR] [--no-reload] | status <binding>"

 die() { echo "discord-service: $*" >&2; exit 1; }
 usage() { echo "$USAGE" >&2; exit 4; }
@@ -48,7 +57,7 @@ render() {
    case ":$path:" in *":$node_dir:"*) ;; *) path="$node_dir:$path" ;; esac
    case "$REPO" in *@*|*'|'*) die "repository path contains a character the template cannot carry: $REPO" ;; esac
    local unit
-    unit="$(sed -e "s|@REPO@|$REPO|g" -e "s|@PATH@|$path|g" "$TEMPLATE")" || return 1
+    unit="$(sed -e "s|@REPO@|$REPO|g" -e "s|@PATH@|$path|g" "${INSTANCE_SED[@]}" "$TEMPLATE")" || return 1
    if [ -n "$root" ]; then
        local node
        node="$(command -v node)"
@@ -101,10 +110,10 @@ install_unit() {
    fi
    cat <<MSG
 next, for one binding:
-  systemctl --user enable --now mosaic-discord@<binding>   start now and at login
-  systemctl --user status mosaic-discord@<binding>
-  journalctl --user -u mosaic-discord@<binding> -f          the connector's log
-  systemctl --user stop mosaic-discord@<binding>            SIGTERM; restartable
+  systemctl --user enable --now $UNIT_PREFIX<binding>   start now and at login
+  systemctl --user status $UNIT_PREFIX<binding>
+  journalctl --user -u $UNIT_PREFIX<binding> -f          the connector's log
+  systemctl --user stop $UNIT_PREFIX<binding>            SIGTERM; restartable
  scripts/discord.sh stop <binding>                         the brake: writes STOP, the unit stays down until STOP is removed
 survive logout and reboot only with lingering on: loginctl enable-linger ${USER:-$(id -un)}
 MSG
@@ -115,7 +124,7 @@ uninstall_unit() {
    local target="$UNIT_DIR/$UNIT_NAME"
    if [ "$RELOAD" = 1 ]; then
        local active
-        active="$(systemctl --user list-units --no-legend --plain 'mosaic-discord@*' 2>/dev/null | awk '$3 == "active" || $3 == "activating" || $3 == "deactivating" {print $1}')"
+        active="$(systemctl --user list-units --no-legend --plain "$UNIT_PREFIX*" 2>/dev/null | awk '$3 == "active" || $3 == "activating" || $3 == "deactivating" {print $1}')"
        [ -z "$active" ] || die "refusing: instance(s) still running: $(echo "$active" | tr '\n' ' ')stop them first"
    fi
    if [ -f "$target" ]; then
@@ -134,7 +143,7 @@ status_unit() {
    [ $# -eq 1 ] || usage
    local binding="$1"
    case "$binding" in ''|*[!A-Za-z0-9_-]*) die "binding name must be [A-Za-z0-9_-]+" ;; esac
-    local unit="mosaic-discord@$binding.service"
+    local unit="$UNIT_PREFIX$binding.service"
    echo "unit: $unit"
    echo "  enabled: $(systemctl --user is-enabled "$unit" 2>&1 || true)"
    echo "  active:  $(systemctl --user is-active "$unit" 2>&1 || true)"
@@ -151,6 +160,7 @@ status_unit() {
        echo "  checkout: $working"
    fi
    local config="${XDG_CONFIG_HOME:-$HOME/.config}/mosaic-dev/config.json"
+    [ -z "$MOSAIC_UNIT_SUFFIX" ] || config="$MOSAIC_INSTANCE_CONFIG"
    local data_root
    data_root="$(node -e 'const c=JSON.parse(require("fs").readFileSync(process.argv[1],"utf8")); process.stdout.write(String(c.dataRoot||""))' "$config" 2>/dev/null || true)"
    if [ -z "$data_root" ]; then
@@ -0,0 +1,142 @@
+# Sourced, not run: stack instance selection for the shell entry points (row 190).
+#
+#   instance_args "$@"   take `--instance NAME` out of the arguments. Sets
+#                        INSTANCE_FLAG (NAME, or empty) and INSTANCE_ARGS (the
+#                        rest, in order). A second --instance or a missing
+#                        NAME exits 4.
+#   instance_select      run `mosaic-config.mjs instance [--instance NAME]`,
+#                        which maps NAME to ~/.config/mosaic-NAME/config.json
+#                        and checks the data root's instance.json claim, then
+#                        set the names below. A refusal exits with the
+#                        loader's code (3 claim or missing config, 4 name or
+#                        mismatch) before the caller reads or writes anything.
+#
+# With no flag, every name is today's and MOSAIC_CONFIG is left as the caller
+# had it. With --instance NAME (other than dev), MOSAIC_CONFIG is exported as
+# NAME's config, so everything the entry point runs reads that config.
+#
+#   BUS_TEMPLATE       [email protected]        | [email protected]
+#   BUS_GLOB           'mosaic-bus@*.service'     | 'mosaic-bus-NAME@*.service'
+#   BUS_DROPIN_GLOBS   unit-path globs whose .conf files can override the bus
+#                      ExecStart: mosaic-bus@*.service.d for the default;
+#                      mosaic-bus-NAME@*.service.d and the shared prefix
+#                      mosaic-bus-.service.d for NAME; then mosaic-.service.d
+#                      and service.d for both
+#   CONSOLE_UNIT       mosaic-webui.service       | mosaic-webui-NAME.service
+#   DISCORD_TEMPLATE   [email protected]    | [email protected]
+#   WRAPPER_NAME       mosaic                     | mosaic-NAME
+#   SESSION_ENV        %h/.config/mosaic-dev/secrets/claude-session.env
+#                                                 | <config dir>/secrets/claude-session.env
+#   INSTANCE_FLAGS     () or (--instance NAME), for the entry points this one runs
+#   INSTANCE_RESERVED  ports a named instance's Console never takes: 7330 (the
+#                      operator's bare Console), 7332 (the tunnel) and 7333
+#                      (the default's tester); empty for the default
+#   INSTANCE_SED       sed arguments that fill @CONFIG_ENV@ and @SESSION_ENV@
+#                      in a unit template: the default deletes the
+#                      @CONFIG_ENV@ line, so its render is byte-identical to
+#                      the template before row 190; NAME gets a comment and
+#                      Environment=MOSAIC_CONFIG=<config>, " [NAME]" after
+#                      the Description, and the Console comment's "sets no
+#                      MOSAIC_*" says it sets MOSAIC_CONFIG (Sage, N3)
+#
+# Also set: MOSAIC_INSTANCE (dev or NAME), MOSAIC_INSTANCE_CONFIG,
+# MOSAIC_INSTANCE_CONFIG_DIR, MOSAIC_INSTANCE_DATA_ROOT (empty when no flag
+# was given and the config is missing or invalid; the caller's own load
+# refuses that as before) and MOSAIC_UNIT_SUFFIX (empty or -NAME).
+
+INSTANCE_FLAG=""
+INSTANCE_ARGS=()
+INSTANCE_FLAGS=()
+INSTANCE_RESERVED=()
+
+instance_args() {
+    local seen=0
+    INSTANCE_FLAG=""
+    INSTANCE_ARGS=()
+    while [ $# -gt 0 ]; do
+        if [ "$1" = "--instance" ]; then
+            if [ "$seen" = 1 ] || [ $# -lt 2 ]; then
+                echo "instance: usage: --instance NAME, given once" >&2
+                exit 4
+            fi
+            INSTANCE_FLAG="$2"
+            seen=1
+            shift 2
+        else
+            INSTANCE_ARGS+=("$1")
+            shift
+        fi
+    done
+}
+
+instance_select() {
+    local here out
+    here="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+    if [ -n "$INSTANCE_FLAG" ]; then
+        out="$(node "$here/mosaic-config.mjs" instance --instance "$INSTANCE_FLAG")" || exit $?
+    else
+        out="$(node "$here/mosaic-config.mjs" instance)" || exit $?
+    fi
+    eval "$out"
+    local s="$MOSAIC_UNIT_SUFFIX"
+    BUS_TEMPLATE="mosaic-bus$s@.service"
+    BUS_GLOB="mosaic-bus$s@*.service"
+    CONSOLE_UNIT="mosaic-webui$s.service"
+    DISCORD_TEMPLATE="mosaic-discord$s@.service"
+    WRAPPER_NAME="mosaic$s"
+    if [ -z "$s" ]; then
+        BUS_DROPIN_GLOBS=('mosaic-bus@*.service.d' 'mosaic-.service.d' 'service.d')
+        SESSION_ENV='%h/.config/mosaic-dev/secrets/claude-session.env'
+        INSTANCE_SED=(-e '/^@CONFIG_ENV@$/d' -e "s|@SESSION_ENV@|$SESSION_ENV|g")
+        return 0
+    fi
+    # systemd expands % and splits Environment= on spaces, and the sed
+    # expressions use |, so a named instance's paths keep to a plain set.
+    case "$MOSAIC_INSTANCE_CONFIG" in
+        *[!A-Za-z0-9/._+-]*)
+            echo "instance: config path contains a character a unit cannot carry: $MOSAIC_INSTANCE_CONFIG" >&2
+            exit 4 ;;
+    esac
+    export MOSAIC_CONFIG="${MOSAIC_CONFIG:-$MOSAIC_INSTANCE_CONFIG}"
+    INSTANCE_FLAGS=(--instance "$MOSAIC_INSTANCE")
+    INSTANCE_RESERVED=(7330 7332 7333)
+    BUS_DROPIN_GLOBS=("mosaic-bus$s@*.service.d" 'mosaic-bus-.service.d' 'mosaic-.service.d' 'service.d')
+    SESSION_ENV="$MOSAIC_INSTANCE_CONFIG_DIR/secrets/claude-session.env"
+    INSTANCE_SED=(
+        -e "s|^@CONFIG_ENV@\$|# Stack instance $MOSAIC_INSTANCE (row 190): the system config its processes read.\\nEnvironment=MOSAIC_CONFIG=$MOSAIC_INSTANCE_CONFIG|"
+        -e "s|@SESSION_ENV@|$SESSION_ENV|g"
+        -e "s|^\\(Description=.*\\)\$|\\1 [$MOSAIC_INSTANCE]|"
+        -e 's|The unit sets no MOSAIC_\*, CLAUDE\*, CODEX\* or PI_\* variable\.$|The unit sets MOSAIC_CONFIG and no other MOSAIC_*, CLAUDE*, CODEX* or PI_* variable.|'
+    )
+}
+
+# instance_port_holder DIR PORT: the installed Console unit in DIR, other than
+# this instance's, whose ExecStart takes PORT as --port or --tester-port.
+# A unit with no --port holds 7332, serve's default. Prints the unit and
+# returns 0, or prints nothing and returns 1. Unit files are host
+# configuration, so reading another instance's is not reading its state.
+instance_port_holder() {
+    local dir="$1" want="$2" file unit line tok next port
+    want="$((10#$want))"
+    for file in "$dir"/mosaic-webui.service "$dir"/mosaic-webui-*.service; do
+        [ -f "$file" ] || continue
+        unit="${file##*/}"
+        [ "$unit" != "$CONSOLE_UNIT" ] || continue
+        line="$(sed -n 's/^ExecStart=//p' "$file" | tail -n 1)"
+        port=7332 next=""
+        local -a ports=() toks=()
+        read -r -a toks <<< "$line"
+        for tok in ${toks[@]+"${toks[@]}"}; do
+            case "$next" in
+                --port) [[ "$tok" =~ ^[0-9]{1,5}$ ]] && port="$((10#$tok))" ;;
+                --tester-port) [[ "$tok" =~ ^[0-9]{1,5}$ ]] && ports+=("$((10#$tok))") ;;
+            esac
+            next="$tok"
+        done
+        ports+=("$port")
+        for port in "${ports[@]}"; do
+            if [ "$port" = "$want" ]; then echo "$unit"; return 0; fi
+        done
+    done
+    return 1
+}
@@ -8,13 +8,30 @@
 *   validate   Load and strictly validate; print resolved config on stdout.
 *   env        Print shell-safe exports for launcher scripts:
 *              MOSAIC_DATA_ROOT, MOSAIC_PROVIDER, MOSAIC_MODEL.
+ *   instance   Print shell-safe exports naming the selected stack instance
+ *              (row 190): MOSAIC_INSTANCE, MOSAIC_INSTANCE_CONFIG,
+ *              MOSAIC_INSTANCE_CONFIG_DIR, MOSAIC_INSTANCE_DATA_ROOT and
+ *              MOSAIC_UNIT_SUFFIX. scripts/instance.sh reads them.
 *
- * Config location: $MOSAIC_CONFIG or ~/.config/mosaic-dev/config.json
+ * Each operation takes an optional `--instance NAME`. NAME matches
+ * ^[a-z][a-z0-9]{1,15}$ and selects ~/.config/mosaic-NAME/config.json;
+ * `dev` is the default instance, so `--instance dev` is the same as no flag.
+ * Without the flag the config is $MOSAIC_CONFIG or
+ * ~/.config/mosaic-dev/config.json, as before.
+ *
+ * A named instance's data root carries <dataRoot>/instance.json, written by
+ * `bootstrap --instance NAME`, naming the instance. With the flag every
+ * operation refuses a root whose marker is missing or names another
+ * instance; `instance` without the flag refuses a root that a named
+ * instance claims.
 *
 * Exit codes:
 *   0 success
 *   2 configuration exists but is invalid (never modified by this tool)
- *   3 configuration is missing for a read operation (validate/env)
+ *   3 configuration is missing for a read operation (validate/env/instance),
+ *     or the data root's instance marker refuses the selection
+ *   4 usage: a bad instance name (instance-name-invalid), or --instance and
+ *     $MOSAIC_CONFIG naming different files (instance-config-mismatch)
 *
 * Invariants (docs/plans/2026-09-02_atomic-mosaic-foundation.md):
 *   - Existing configuration is never overwritten.
@@ -26,22 +43,119 @@ import fs from "node:fs";
 import os from "node:os";
 import path from "node:path";
 import process from "node:process";
+import { pathToFileURL } from "node:url";

 const SUPPORTED_CONFIG_VERSION = 1;
 const SUPPORTED_ENVIRONMENTS = new Set(["development", "production"]);
 const SUPPORTED_BACKENDS = new Set(["docker"]);
 const SUPPORTED_ADAPTERS = new Set(["pi", "mock"]); // mock: test-only, see adapters/README.md
 const NAME_PATTERN = /^[A-Za-z0-9][A-Za-z0-9._:/-]{0,199}$/;
+// Row 190: stack instance names. No hyphen, so systemd's prefix drop-ins
+// for mosaic-bus-NAME@ stay a fixed list and no name prefixes another's units.
+const INSTANCE_PATTERN = /^[a-z][a-z0-9]{1,15}$/;
+const DEFAULT_INSTANCE = "dev";
+const MARKER = "instance.json";

-function fail(exitCode, message) {
-  process.stderr.write(`mosaic-config: ${message}\n`);
-  process.exit(exitCode);
+class Failure extends Error {
+  constructor(exitCode, message) {
+    super(message);
+    this.exitCode = exitCode;
+  }
 }

-function configPath() {
-  return process.env.MOSAIC_CONFIG
-    ? path.resolve(process.env.MOSAIC_CONFIG)
-    : path.join(os.homedir(), ".config", "mosaic-dev", "config.json");
+function fail(exitCode, message) {
+  throw new Failure(exitCode, message);
+}
+
+function instancePath(name) {
+  return path.join(os.homedir(), ".config", `mosaic-${name}`, "config.json");
+}
+
+function realOrNull(file) {
+  try {
+    return fs.realpathSync(file);
+  } catch {
+    return null;
+  }
+}
+
+// The config file for a selection. Without --instance, as before. With it,
+// NAME's file; a $MOSAIC_CONFIG beside it must be the same file.
+function configPath(instance) {
+  if (instance === null) {
+    return process.env.MOSAIC_CONFIG
+      ? path.resolve(process.env.MOSAIC_CONFIG)
+      : instancePath(DEFAULT_INSTANCE);
+  }
+  const named = instancePath(instance);
+  if (process.env.MOSAIC_CONFIG) {
+    const given = path.resolve(process.env.MOSAIC_CONFIG);
+    const same = given === named || (realOrNull(given) !== null && realOrNull(given) === realOrNull(named));
+    if (!same) {
+      fail(4, `instance-config-mismatch: --instance ${instance} names ${named}, but MOSAIC_CONFIG names ${given}`);
+    }
+  }
+  return named;
+}
+
+// Operation arguments: nothing, or `--instance NAME` once.
+function parseArgs(args) {
+  if (args.length === 0) return null;
+  if (args.length !== 2 || args[0] !== "--instance") {
+    fail(4, `usage: mosaic-config.mjs ${operation ?? "OP"} [--instance NAME]`);
+  }
+  const name = args[1];
+  if (!INSTANCE_PATTERN.test(name)) {
+    fail(4, `instance-name-invalid: ${JSON.stringify(name)} must match ${INSTANCE_PATTERN}`);
+  }
+  return name;
+}
+
+function isNamed(instance) {
+  return instance !== null && instance !== DEFAULT_INSTANCE;
+}
+
+// The marker in a data root: null when absent, else its name. Anything else
+// at the path refuses.
+function readMarker(dataRoot) {
+  const file = path.join(dataRoot, MARKER);
+  let stat;
+  try {
+    stat = fs.lstatSync(file);
+  } catch (error) {
+    if (error.code === "ENOENT") return null;
+    fail(3, `instance-root-unclaimed: cannot read ${file} (${error.code})`);
+  }
+  if (!stat.isFile() || stat.isSymbolicLink()) {
+    fail(3, `instance-root-unclaimed: ${file} must be a regular, non-symbolic-link file`);
+  }
+  let marker;
+  try {
+    marker = JSON.parse(fs.readFileSync(file, "utf8"));
+  } catch (error) {
+    fail(3, `instance-root-unclaimed: ${file} is not a valid marker (${error.message})`);
+  }
+  if (!isPlainObject(marker) || Object.keys(marker).sort().join(",") !== "instanceVersion,name"
+      || marker.instanceVersion !== 1 || typeof marker.name !== "string" || !INSTANCE_PATTERN.test(marker.name)) {
+    fail(3, `instance-root-unclaimed: ${file} is not a valid marker ({"instanceVersion":1,"name":NAME})`);
+  }
+  return marker.name;
+}
+
+// The claim check (row 190 D2). A named instance needs its own marker; the
+// default needs none, or one naming dev.
+function checkClaim(dataRoot, instance) {
+  const owner = readMarker(dataRoot);
+  if (isNamed(instance)) {
+    if (owner === null) {
+      fail(3, `instance-root-unclaimed: ${dataRoot} holds no ${MARKER} naming ${instance} (scripts/bootstrap.sh --instance ${instance} claims a new root)`);
+    }
+    if (owner !== instance) {
+      fail(3, `instance-root-mismatch: ${dataRoot} is claimed by instance ${owner}, not ${instance}`);
+    }
+  } else if (owner !== null && owner !== DEFAULT_INSTANCE) {
+    fail(3, `instance-root-mismatch: ${dataRoot} is claimed by instance ${owner}; select it with --instance ${owner}`);
+  }
 }

 function readRaw(file) {
@@ -106,13 +220,30 @@ function isAncestorOf(ancestor, candidate) {
  return rel !== "" && !rel.startsWith("..") && !path.isAbsolute(rel);
 }

-function validate(document, file) {
+// Q175 phase 1 (#1690): the optional `console` key, checked for shape only by the Console's own
+// checker. It is imported only when the key is there, so a config without it never needs the
+// Console's code, and a copy of this file alone still reads one.
+async function validateConsole(value) {
+  let checkConsole;
+  try {
+    ({ checkConsole } = await import(pathToFileURL(path.join(import.meta.dirname, "..", "packages", "webui", "src", "sso-config.mjs")).href));
+  } catch {
+    fail(2, 'the "console" key needs packages/webui/src/sso-config.mjs beside this loader');
+  }
+  try {
+    return checkConsole(value);
+  } catch (error) {
+    fail(2, error.message);
+  }
+}
+
+async function validate(document, file) {
  if (!isPlainObject(document)) {
    fail(2, "configuration must be a JSON object");
  }
  rejectUnknownKeys(
    document,
-    ["configVersion", "environment", "dataRoot", "execution"],
+    ["configVersion", "environment", "dataRoot", "execution", "console"],
    "configuration",
  );

@@ -146,6 +277,10 @@ function validate(document, file) {
    fail(2, `unsupported execution.adapter: ${JSON.stringify(adapter)} (supported: ${[...SUPPORTED_ADAPTERS].join(", ")})`);
  }

+  // Last, so the older checks keep their order. The key is in the output only when the file has
+  // it, so a config without it prints what it always printed.
+  const consoleKey = Object.hasOwn(document, "console") ? await validateConsole(document.console) : undefined;
+
  return {
    configVersion: document.configVersion,
    environment: document.environment,
@@ -156,13 +291,15 @@ function validate(document, file) {
      model: document.execution.model,
      adapter,
    },
+    ...(consoleKey === undefined ? {} : { console: consoleKey }),
  };
 }

-function load(file) {
+async function load(file, instance = null) {
  const raw = readRaw(file);
  if (raw === null) {
-    fail(3, `configuration not found: ${file} (run scripts/bootstrap.sh to create it)`);
+    const bootstrap = isNamed(instance) ? `scripts/bootstrap.sh --instance ${instance}` : "scripts/bootstrap.sh";
+    fail(3, `configuration not found: ${file} (run ${bootstrap} to create it)`);
  }
  let document;
  try {
@@ -170,74 +307,185 @@ function load(file) {
  } catch (error) {
    fail(2, `configuration is not valid JSON (${file}): ${error.message}`);
  }
-  return validate(document, file);
+  return await validate(document, file);
 }

 function shellQuote(value) {
  return `'${String(value).replaceAll("'", `'\\''`)}'`;
 }

-const DEFAULT_CONFIG = {
-  configVersion: 1,
-  environment: "development",
-  dataRoot: path.join(os.homedir(), ".mosaic-dev"),
-  execution: {
-    backend: "docker",
-    provider: "zai",
-    model: "glm-5.3-flash",
-  },
-};
+function defaultConfig(dataRoot) {
+  return {
+    configVersion: 1,
+    environment: "development",
+    dataRoot,
+    execution: {
+      backend: "docker",
+      provider: "zai",
+      model: "glm-5.3-flash",
+    },
+  };
+}
+
+const DEFAULT_CONFIG = defaultConfig(path.join(os.homedir(), ".mosaic-dev"));
+
+// 'wx': creation is exclusive; an existing file is never overwritten, and a
+// symbolic link at the path is never followed.
+function createExclusive(file, text, label = file) {
+  let fd;
+  try {
+    fd = fs.openSync(file, "wx", 0o644);
+    fs.writeFileSync(fd, text);
+    return true;
+  } catch (error) {
+    if (error.code === "EEXIST") return false;
+    fail(1, `unable to create ${label}: ${error.message}`);
+  } finally {
+    if (fd !== undefined) fs.closeSync(fd);
+  }
+}
+
+async function bootstrapDefault(file) {
+  if (fs.existsSync(file)) {
+    await load(file); // validate only; never rewrite
+    process.stderr.write(`mosaic-config: configuration already present, validated without changes: ${file}\n`);
+    return;
+  }
+  fs.mkdirSync(path.dirname(file), { recursive: true });
+  if (!createExclusive(file, `${JSON.stringify(DEFAULT_CONFIG, null, 2)}\n`, "configuration")) {
+    await load(file);
+    return;
+  }
+  await load(file);
+  process.stderr.write(`mosaic-config: created default configuration: ${file}\n`);
+}
+
+// Row 190 D2: NAME's config dir (0700), its config, then the claimed data
+// root. The root is checked before anything is written, so a refusal
+// writes nothing.
+async function bootstrapNamed(file, instance) {
+  if (fs.existsSync(file)) {
+    const resolved = await load(file, instance); // validate only; never rewrite
+    checkClaim(resolved.dataRoot, instance);
+    process.stderr.write(`mosaic-config: configuration already present, validated without changes: ${file}\n`);
+    return;
+  }
+  const dataRoot = path.join(os.homedir(), `.mosaic-${instance}`);
+  let entries = null;
+  try {
+    const stat = fs.lstatSync(dataRoot);
+    if (!stat.isDirectory()) fail(3, `instance-root-unclaimed: ${dataRoot} exists and is not a directory; nothing was written`);
+    entries = fs.readdirSync(dataRoot);
+  } catch (error) {
+    if (error instanceof Failure) throw error;
+    if (error.code !== "ENOENT") fail(3, `instance-root-unclaimed: cannot read ${dataRoot} (${error.code}); nothing was written`);
+  }
+  if (entries !== null && entries.length > 0 && readMarker(dataRoot) !== instance) {
+    fail(3, `instance-root-unclaimed: ${dataRoot} exists, is not empty and holds no ${MARKER} naming ${instance}; nothing was written`);
+  }
+  const configDir = path.dirname(file);
+  fs.mkdirSync(path.dirname(configDir), { recursive: true });
+  try {
+    fs.mkdirSync(configDir, { mode: 0o700 });
+  } catch (error) {
+    if (error.code !== "EEXIST") fail(1, `unable to create ${configDir}: ${error.message}`);
+  }
+  if (!createExclusive(file, `${JSON.stringify(defaultConfig(dataRoot), null, 2)}\n`)) {
+    const resolved = await load(file, instance);
+    checkClaim(resolved.dataRoot, instance);
+    return;
+  }
+  const resolved = await load(file, instance);
+  try {
+    fs.mkdirSync(resolved.dataRoot, { mode: 0o700 });
+  } catch (error) {
+    if (error.code !== "EEXIST") fail(1, `unable to create ${resolved.dataRoot}: ${error.message}`);
+  }
+  createExclusive(path.join(resolved.dataRoot, MARKER), `${JSON.stringify({ instanceVersion: 1, name: instance })}\n`);
+  checkClaim(resolved.dataRoot, instance);
+  process.stderr.write(`mosaic-config: created configuration for instance ${instance}: ${file}, data root ${resolved.dataRoot}\n`);
+}
+
+// Without --instance, a missing or invalid config is left to the caller's
+// own load, as before; only a loaded config's root is checked.
+async function selected(instance) {
+  const file = configPath(instance);
+  let dataRoot = "";
+  if (isNamed(instance)) {
+    dataRoot = (await load(file, instance)).dataRoot;
+    checkClaim(dataRoot, instance);
+  } else {
+    let resolved = null;
+    try {
+      resolved = readRaw(file) === null ? null : await load(file);
+    } catch (error) {
+      if (!(error instanceof Failure)) throw error;
+    }
+    if (resolved !== null) {
+      dataRoot = resolved.dataRoot;
+      checkClaim(dataRoot, instance);
+    }
+  }
+  const name = isNamed(instance) ? instance : DEFAULT_INSTANCE;
+  return [
+    `MOSAIC_INSTANCE=${shellQuote(name)}`,
+    `MOSAIC_INSTANCE_CONFIG=${shellQuote(path.resolve(file))}`,
+    `MOSAIC_INSTANCE_CONFIG_DIR=${shellQuote(path.dirname(path.resolve(file)))}`,
+    `MOSAIC_INSTANCE_DATA_ROOT=${shellQuote(dataRoot)}`,
+    `MOSAIC_UNIT_SUFFIX=${shellQuote(isNamed(instance) ? `-${instance}` : "")}`,
+    "",
+  ].join("\n");
+}
+
+async function loadSelected(instance) {
+  const file = configPath(instance);
+  const resolved = await load(file, instance);
+  if (isNamed(instance)) checkClaim(resolved.dataRoot, instance);
+  return resolved;
+}

 const operation = process.argv[2];
-const file = configPath();

-switch (operation) {
-  case "bootstrap": {
-    if (fs.existsSync(file)) {
-      load(file); // validate only; never rewrite
-      process.stderr.write(`mosaic-config: configuration already present, validated without changes: ${file}\n`);
+try {
+  if (!["bootstrap", "validate", "env", "instance"].includes(operation)) {
+    fail(1, `unknown operation: ${JSON.stringify(operation ?? "")} (expected bootstrap | validate | env | instance)`);
+  }
+  const instance = parseArgs(process.argv.slice(3));
+  switch (operation) {
+    case "bootstrap": {
+      const file = configPath(instance);
+      if (isNamed(instance)) await bootstrapNamed(file, instance);
+      else await bootstrapDefault(file);
      process.exit(0);
    }
-    fs.mkdirSync(path.dirname(file), { recursive: true });
-    let fd;
-    try {
-      // 'wx': creation is exclusive; an existing file is never overwritten.
-      fd = fs.openSync(file, "wx", 0o644);
-      fs.writeFileSync(fd, `${JSON.stringify(DEFAULT_CONFIG, null, 2)}\n`);
-    } catch (error) {
-      if (error.code === "EEXIST") {
-        load(file);
-        process.exit(0);
-      }
-      fail(1, `unable to create configuration: ${error.message}`);
-    } finally {
-      if (fd !== undefined) fs.closeSync(fd);
+
+    case "validate": {
+      const resolved = await loadSelected(instance);
+      process.stdout.write(`${JSON.stringify(resolved, null, 2)}\n`);
+      process.exit(0);
    }
-    load(file);
-    process.stderr.write(`mosaic-config: created default configuration: ${file}\n`);
-    process.exit(0);
-  }

-  case "validate": {
-    const resolved = load(file);
-    process.stdout.write(`${JSON.stringify(resolved, null, 2)}\n`);
-    process.exit(0);
-  }
+    case "env": {
+      const resolved = await loadSelected(instance);
+      process.stdout.write(
+        [
+          `MOSAIC_DATA_ROOT=${shellQuote(resolved.dataRoot)}`,
+          `MOSAIC_PROVIDER=${shellQuote(resolved.execution.provider)}`,
+          `MOSAIC_MODEL=${shellQuote(resolved.execution.model)}`,
+          `MOSAIC_ADAPTER=${shellQuote(resolved.execution.adapter)}`,
+          "",
+        ].join("\n"),
+      );
+      process.exit(0);
+    }

-  case "env": {
-    const resolved = load(file);
-    process.stdout.write(
-      [
-        `MOSAIC_DATA_ROOT=${shellQuote(resolved.dataRoot)}`,
-        `MOSAIC_PROVIDER=${shellQuote(resolved.execution.provider)}`,
-        `MOSAIC_MODEL=${shellQuote(resolved.execution.model)}`,
-        `MOSAIC_ADAPTER=${shellQuote(resolved.execution.adapter)}`,
-        "",
-      ].join("\n"),
-    );
-    process.exit(0);
+    case "instance": {
+      process.stdout.write(await selected(instance));
+      process.exit(0);
+    }
  }
-
-  default:
-    fail(1, `unknown operation: ${JSON.stringify(operation ?? "")} (expected bootstrap | validate | env)`);
+} catch (error) {
+  if (!(error instanceof Failure)) throw error;
+  process.stderr.write(`mosaic-config: ${error.message}\n`);
+  process.exit(error.exitCode);
 }
@@ -1,20 +1,22 @@
 #!/usr/bin/env bash
 # One immutable pushed tree for the bus, Console and human CLI (#1579).
 # copy creates files only; wrapper is a separately Mos-gated live step.
+# wrapper and check take --instance NAME (row 190): the units mosaic-bus-NAME@ and mosaic-webui-NAME
+# and the wrapper $BIN/mosaic-NAME, which sets NAME's MOSAIC_CONFIG. check needs --business for NAME.
 set -euo pipefail
 REPO="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
 COPIES="${XDG_DATA_HOME:-$HOME/.local/share}/mosaic-stack/copies"
 BIN="$HOME/.npm-global/bin"
-BUSINESS=mosaic-stack
+BUSINESS=mosaic-stack BUSINESS_SET=0
 ALLOW_WORKTREE=0
 MARKER='# mosaic-cli wrapper (Q81, agents/sage/work/q81/mosaic-cli.sh)'
-usage() { echo 'usage: stack-copy.sh copy COMMIT [--copies DIR] [--allow-worktree] | wrapper ID [--copies DIR] [--bin DIR] | check [--copies DIR] [--bin DIR] [--business ID]' >&2; exit "${1:-4}"; }
+usage() { echo 'usage: stack-copy.sh copy COMMIT [--copies DIR] [--allow-worktree] | wrapper ID [--instance NAME] [--copies DIR] [--bin DIR] | check [--instance NAME] [--copies DIR] [--bin DIR] [--business ID]' >&2; exit "${1:-4}"; }
 die() { echo "stack-copy: $*" >&2; exit 1; }
 plain_path() { case "$1" in /*) ;; *) die "$2 must be an absolute path: $1" ;; esac; case "$1" in *[!A-Za-z0-9/._+-]*) die "$2 contains a character the unit cannot carry: $1" ;; esac; }
 parse() { while [ $# -gt 0 ]; do case "$1" in
 --copies) [ $# -ge 2 ] || usage; COPIES="$2"; shift 2;;
 --bin) [ "$CMD" != copy ] && [ $# -ge 2 ] || usage; BIN="$2";shift 2;;
- --business) [ "$CMD" = check ] && [ $# -ge 2 ] || usage; BUSINESS="$2";shift 2;;
+ --business) [ "$CMD" = check ] && [ $# -ge 2 ] || usage; BUSINESS="$2";BUSINESS_SET=1;shift 2;;
 --allow-worktree) [ "$CMD" = copy ] || usage; ALLOW_WORKTREE=1;shift;;
 *) usage;; esac; done; plain_path "$COPIES" 'copies directory'; }
 copy_root() { [[ "$ID" =~ ^[0-9a-f]{40}$ ]] || die '--copy must be a full 40-character commit id'; [ -f "$COPIES/$ID/scripts/mosaic" ] || die "no copy $ID in $COPIES"; echo "$COPIES/$ID"; }
@@ -64,6 +66,7 @@ copy_commit() {
 echo "copied: $target"
 }
 wrapper() {
+ [ -z "$MOSAIC_UNIT_SUFFIX" ] || { wrapper_instance; return; }
 plain_path "$BIN" 'bin directory'
 local root file lease tmp
 root="$(copy_root)";file="$BIN/mosaic"
@@ -77,6 +80,22 @@ wrapper() {
 chmod 0755 "$tmp";mv -f "$tmp" "$file";trap - EXIT
 echo "wrapper: $root"
 }
+# Row 190: $BIN/mosaic-NAME. It creates the file or replaces one with its own marker, never another.
+# NAME's config path is plain (instance.sh refuses any other), so it goes in single quotes as is.
+wrapper_instance() {
+ plain_path "$BIN" 'bin directory'
+ local root file tmp
+ root="$(copy_root)";file="$BIN/$WRAPPER_NAME"
+ if [ -e "$file" ] || [ -L "$file" ]; then
+  [ -f "$file" ] && [ ! -L "$file" ] || die "refusing: wrapper is not regular, or a symlink: $file"
+  [ "$(sed -n '2p' "$file")" = "$INSTANCE_MARKER" ] || die "refusing: foreign wrapper (missing the instance $MOSAIC_INSTANCE marker on line 2): $file"
+ fi
+ tmp="$(mktemp "$BIN/.$WRAPPER_NAME.XXXXXX")"
+ trap 'rm -f "$tmp"' EXIT
+ printf '#!/usr/bin/env bash\n%s\n# CLI runs from pinned copy: %s\nexport MOSAIC_CONFIG='"'"'%s'"'"'\nexec "%s/scripts/mosaic" "$@"\n' "$INSTANCE_MARKER" "$root" "$MOSAIC_INSTANCE_CONFIG" "$root" > "$tmp"
+ chmod 0755 "$tmp";mv -f "$tmp" "$file";trap - EXIT
+ echo "wrapper: $root"
+}
 unit_root() {
 local out load root exec_start
 out="$(systemctl --user show "$1" -p LoadState -p WorkingDirectory -p ExecStart 2>/dev/null)" || { echo 'absent (systemctl read failed)';return; }
@@ -84,29 +103,37 @@ unit_root() {
 exec_start="$(sed -n 's/^ExecStart=//p' <<< "$out")"
 if [ "$load" != loaded ] || [ -z "$root" ];then echo absent;return;fi
 case "$1" in
-  mosaic-bus@*) [[ "$exec_start" == *"path=$root/scripts/mosaic ;"* ]] || { echo "$root (ExecStart mismatch)";return; };;
+  mosaic-bus@*|mosaic-bus-*@*) [[ "$exec_start" == *"path=$root/scripts/mosaic ;"* ]] || { echo "$root (ExecStart mismatch)";return; };;
  mosaic-webui*) [[ "$exec_start" == *"$root/packages/webui/src/cli.mjs serve"* ]] || { echo "$root (ExecStart mismatch)";return; };;
 esac
 echo "$root"
 }
 check() {
 plain_path "$BIN" 'bin directory';[[ "$BUSINESS" =~ ^[a-z0-9][a-z0-9-]*$ ]] || die 'invalid business id'
- local bus console cli=absent line path
- bus="$(unit_root "mosaic-bus@$BUSINESS.service")";console="$(unit_root mosaic-webui.service)"
- if [ -f "$BIN/mosaic" ] && [ ! -L "$BIN/mosaic" ] && [ "$(sed -n '2p' "$BIN/mosaic")" = "$MARKER" ]; then
-  line="$(tail -n 1 "$BIN/mosaic")"
+ local bus console cli=absent line path marker="$MARKER" wfile="$BIN/$WRAPPER_NAME"
+ [ -z "$MOSAIC_UNIT_SUFFIX" ] || marker="$INSTANCE_MARKER"
+ bus="$(unit_root "${BUS_TEMPLATE%.service}$BUSINESS.service")";console="$(unit_root "$CONSOLE_UNIT")"
+ if [ -f "$wfile" ] && [ ! -L "$wfile" ] && [ "$(sed -n '2p' "$wfile")" = "$marker" ]; then
+  line="$(tail -n 1 "$wfile")"
  path="${line#exec \"}";path="${path%\" \"\$@\"}"
  if [ "$line" = "exec \"$path\" \"\$@\"" ] && [[ "$path" == */scripts/mosaic ]];then cli="${path%/scripts/mosaic}";fi
+  # A named wrapper must also carry NAME's config, as wrapper_instance writes it.
+  if [ -n "$MOSAIC_UNIT_SUFFIX" ] && [ "$cli" != absent ] && [ "$(sed -n '4p' "$wfile")" != "export MOSAIC_CONFIG='$MOSAIC_INSTANCE_CONFIG'" ];then cli="$cli (MOSAIC_CONFIG mismatch)";fi
 fi
 printf 'bus: %s\nConsole: %s\nCLI: %s\n' "$bus" "$console" "$cli"
 [[ "$bus" == "$COPIES/"* ]] && [[ "${bus#"$COPIES/"}" =~ ^[0-9a-f]{40}$ ]] && [ -f "$bus/scripts/mosaic" ] && [ "$bus" = "$console" ] && [ "$bus" = "$cli" ]
 }
 # Sourced (stack-release.sh): define the functions, run nothing.
 [ "${BASH_SOURCE[0]}" = "$0" ] || return 0
+. "$REPO/scripts/instance.sh"
+instance_args "$@"
+set -- ${INSTANCE_ARGS[@]+"${INSTANCE_ARGS[@]}"}
 [ $# -gt 0 ] || usage
 CMD="$1";shift
+case "$CMD" in check|wrapper) instance_select;; *) [ -z "$INSTANCE_FLAG" ] || usage;; esac
+INSTANCE_MARKER="# mosaic-cli wrapper, instance ${MOSAIC_INSTANCE:-dev} (row 190)"
 case "$CMD" in
 copy|wrapper) [ $# -gt 0 ] || usage;ID="$1";shift;case "$ID" in -*)usage;;esac;parse "$@";if [ "$CMD" = copy ];then copy_commit;else wrapper;fi;;
- check) parse "$@";check;;
+ check) parse "$@";[ -z "$MOSAIC_UNIT_SUFFIX" ] || [ "$BUSINESS_SET" = 1 ] || usage;check;;
 -h|--help) usage 0;;
 *) usage;;esac
@@ -3,7 +3,7 @@
 # Moves the bus, the Console and the human CLI from the pointer's copy to another copy together,
 # behind a health gate, and puts the old stack back inside the same run when the gate fails.
 # Console tester listener flags follow target support (row 176, #1674); so does the row 178 proof
-# pair, which activate sets or drops (row 187, #1685).
+# pair, which activate sets or drops (row 187, #1685). activate --no-send drops --send (row 189, #1687).
 # Design and tests: agents/darkwing/work/queue-162/BUILD.md.
 #
 # Who runs it. Decision 96 (Mos, mos-0716) lets this script stop and start the live units under
@@ -24,24 +24,26 @@ set -euo pipefail
 cd "$(dirname "$0")/.."
 REPO="$(pwd)"
 source scripts/common.sh
+source scripts/instance.sh

 COPIES="${XDG_DATA_HOME:-$HOME/.local/share}/mosaic-stack/copies"
 BIN="$HOME/.npm-global/bin"
 UNIT_DIR="${XDG_CONFIG_HOME:-$HOME/.config}/systemd/user"
-CONSOLE_UNIT=mosaic-webui.service
 TIMEOUT=60 WANT_PM=0 AFTER_HARNESS=0 MIGRATE=0 PLAN=0 RESTORE="" EVENTS="" TESTER_PORT=""
-PROOF_HEADER="" PROOF_FILE="" NO_PROOF=0 R_BACKUP="" R_PORT=""
+PROOF_HEADER="" PROOF_FILE="" NO_PROOF=0 NO_SEND=0 R_BACKUP="" R_PORT=""

 usage() {
    cat >&2 <<'USAGE'
 usage: stack-release.sh adopt BUSINESS
       stack-release.sh activate ID BUSINESS [--pm | --pm-after-harness] [--migrate] [--tester-port N]
-           [--proof-header NAME --proof-file PATH | --no-proof] [--timeout S] [--plan]
+           [--proof-header NAME --proof-file PATH | --no-proof] [--no-send] [--timeout S] [--plan]
       stack-release.sh pm-on BUSINESS [--timeout S]
       stack-release.sh rollback BUSINESS [--restore ACTIVATION [--events N]] [--timeout S] [--plan]
       stack-release.sh status BUSINESS
       stack-release.sh rehearse ID BUSINESS --backup ACTIVATION|PATH --port N [--timeout S]
-common options: --copies DIR, --bin DIR
+common options: --copies DIR, --bin DIR, --instance NAME
+--instance NAME (row 190) runs on stack instance NAME: its config, data root, units and the wrapper
+mosaic-NAME. Without it, the default instance, as before.
 --events N is the total of the per-table counts the post-backup-events refusal prints: events and
 every table in COUNTED.
 USAGE
@@ -69,7 +71,10 @@ refuse() {
 # Reject tunnel/main ports and anything other than a whole high port (exit 4 via usage).
 valid_tester_port() {
    [[ "$1" =~ ^[0-9]{1,5}$ ]] && [ "$((10#$1))" -ge 1024 ] && [ "$((10#$1))" -le 65535 ] &&
-        [ "$((10#$1))" -ne 7332 ] && [ "$((10#$1))" -ne "$2" ]
+        [ "$((10#$1))" -ne 7332 ] && [ "$((10#$1))" -ne "$2" ] || return 1
+    # Row 190: a named instance's Console never takes 7330, 7332 or 7333.
+    local r
+    for r in "${INSTANCE_RESERVED[@]}"; do [ "$((10#$1))" -ne "$r" ] || return 1; done
 }

 parse_opts() {
@@ -85,6 +90,7 @@ parse_opts() {
            --proof-header) [ "$OP" = activate ] && [ $# -ge 2 ] && [ -n "$2" ] || usage; PROOF_HEADER="$2"; shift 2 ;;
            --proof-file) [ "$OP" = activate ] && [ $# -ge 2 ] && [ -n "$2" ] || usage; PROOF_FILE="$2"; shift 2 ;;
            --no-proof) [ "$OP" = activate ] || usage; NO_PROOF=1; shift ;;
+            --no-send) [ "$OP" = activate ] || usage; NO_SEND=1; shift ;;
            --migrate) [ "$OP" = activate ] || usage; MIGRATE=1; shift ;;
            --restore) [ "$OP" = rollback ] && [ $# -ge 2 ] && [[ "$2" =~ ^[0-9]{8}T[0-9]{6}Z-[0-9a-f]{12}(-[1-9])?$ ]] || usage; RESTORE="$2"; shift 2 ;;
            --backup) [ "$OP" = rehearse ] && [ $# -ge 2 ] && { [[ "$2" =~ ^[0-9]{8}T[0-9]{6}Z-[0-9a-f]{12}(-[1-9])?$ ]] || [[ "$2" =~ ^/[A-Za-z0-9/._+-]*$ ]]; } || usage; R_BACKUP="$2"; shift 2 ;;
@@ -244,14 +250,16 @@ target_schema() {
 in_chain() { local v; for v in "${T_CHAIN[@]}"; do [ "$v" != "$1" ] || return 0; done; return 1; }

 # The item 3 checks on the target copy, in order: copy, schema, already-active. An activate that
-# sets a proof pair, or drops the pointer's pair with --no-proof, may name the pointer's copy: it
-# re-pins the live copy with new Console flags (row 187, Part B's B3 and B-R1).
+# sets a proof pair, drops the pointer's pair with --no-proof, or drops the pointer's --send with
+# --no-send, may name the pointer's copy: it re-pins the live copy with new Console flags (row 187,
+# Part B's B3 and B-R1; row 189, mos-0972).
 check_target() {
    copy_exists "$TO" 2>/dev/null || refuse copy-missing "no copy $TO in $COPIES"
    copy_ok "$TO" 2>/dev/null || refuse copy-unreachable "$TO is not reachable from refactor and origin/refactor"
    target_schema "$TO" || refuse copy-schema-unknown "cannot read SCHEMA_VERSION and its chain from $COPIES/$TO/packages/bus/src/store.mjs"
    [ "$TO" != "$P_COPY" ] || [ -n "$PROOF_HEADER" ] ||
        { [ "$NO_PROOF" = 1 ] && [[ " ${P_CONSOLE[*]} " == *" --proof-header "* ]]; } ||
+        { [ "$NO_SEND" = 1 ] && [[ " ${P_CONSOLE[*]} " == *" --send "* ]]; } ||
        refuse already-active "$TO is the pointer's copy"
 }

@@ -413,16 +421,17 @@ capture() {
    mkdir -m 0700 "$RS" 2>/dev/null || return 1
    STEPS="$RS/steps.log"
    local u d
-    for u in [email protected] "$CONSOLE_UNIT"; do
+    for u in "$BUS_TEMPLATE" "$CONSOLE_UNIT"; do
        [ -f "$UNIT_DIR/$u" ] || { say "capture: no $UNIT_DIR/$u"; return 1; }
        cp -p "$UNIT_DIR/$u" "$RS/$u" || return 1
    done
-    for d in [email protected] "mosaic-bus@$BUSINESS.service.d" "$CONSOLE_UNIT.d"; do
+    # This instance's own directories only; the shared prefix ones are never captured (row 190).
+    for d in "$BUS_TEMPLATE.d" "$BUS_UNIT.d" "$CONSOLE_UNIT.d"; do
        [ ! -d "$UNIT_DIR/$d" ] || cp -pr "$UNIT_DIR/$d" "$RS/$d" || return 1
    done
-    [ -f "$BIN/mosaic" ] || { say "capture: no wrapper $BIN/mosaic"; return 1; }
-    cp -p "$BIN/mosaic" "$RS/wrapper" || return 1
-    stat -c %a "$BIN/mosaic" > "$RS/WRAPPER_MODE" || return 1
+    [ -f "$BIN/$WRAPPER_NAME" ] || { say "capture: no wrapper $BIN/$WRAPPER_NAME"; return 1; }
+    cp -p "$BIN/$WRAPPER_NAME" "$RS/wrapper" || return 1
+    stat -c %a "$BIN/$WRAPPER_NAME" > "$RS/WRAPPER_MODE" || return 1
    for u in "$BUS_UNIT" "$CONSOLE_UNIT"; do show "$u" > "$RS/show-$u.txt" || return 1; done
    sums "$RS" > "$RS/SHA256SUMS" || return 1
    say "captured the rollback set: $RS"
@@ -455,9 +464,9 @@ install_stack() {
    local id="$1" pm="$2" claude="$3"; shift 3
    local -a pmflag=()
    [ "$pm" = 0 ] || pmflag=(--pm)
-    scripts/bus-service.sh install --copy "$id" --copies "$COPIES" "${pmflag[@]}" --claude "$claude" >> "$STEPS" 2>&1 || { FAIL=install-bus; return 1; }
-    scripts/webui-service.sh install --copy "$id" --copies "$COPIES" "$@" >> "$STEPS" 2>&1 || { FAIL=install-console; return 1; }
-    scripts/stack-copy.sh wrapper "$id" --copies "$COPIES" --bin "$BIN" >> "$STEPS" 2>&1 || { FAIL=wrapper; return 1; }
+    scripts/bus-service.sh install "${INSTANCE_FLAGS[@]}" --copy "$id" --copies "$COPIES" "${pmflag[@]}" --claude "$claude" >> "$STEPS" 2>&1 || { FAIL=install-bus; return 1; }
+    scripts/webui-service.sh install "${INSTANCE_FLAGS[@]}" --copy "$id" --copies "$COPIES" "$@" >> "$STEPS" 2>&1 || { FAIL=install-console; return 1; }
+    scripts/stack-copy.sh wrapper "$id" "${INSTANCE_FLAGS[@]}" --copies "$COPIES" --bin "$BIN" >> "$STEPS" 2>&1 || { FAIL=wrapper; return 1; }
    say "installed $id"
 }

@@ -483,7 +492,7 @@ process.stdout.write(why);' -- "$out" "$BUSINESS" "$main" "$START_MS" 2>&1)" ||
    node -e '
 fetch(`http://127.0.0.1:${process.argv[1]}/healthz`,{signal:AbortSignal.timeout(5000)}).then((r)=>process.exit(r.status===200?0:1),()=>process.exit(1));' -- "$(console_port)" || return 1
    GATE=copy-check
-    out="$(scripts/stack-copy.sh check --copies "$COPIES" --bin "$BIN" --business "$BUSINESS" 2>/dev/null)" || return 1
+    out="$(scripts/stack-copy.sh check "${INSTANCE_FLAGS[@]}" --copies "$COPIES" --bin "$BIN" --business "$BUSINESS" 2>/dev/null)" || return 1
    # check passes when the three agree on one copy; this run needs it to be the target (row 166 item 3).
    out="$(sed -n 's/^bus: //p' <<< "$out")"
    [ "$out" = "$copy" ] || { GATE_WHY="the bus, Console and CLI agree on $out, not $copy"; return 1; }
@@ -530,10 +539,10 @@ gate() {
 # Puts back the captured unit files, drop-ins and wrapper, checked against SHA256SUMS.
 put_back() {
    local u f rel tmp
-    for u in [email protected] "$CONSOLE_UNIT"; do
+    for u in "$BUS_TEMPLATE" "$CONSOLE_UNIT"; do
        tmp="$(mktemp "$UNIT_DIR/.$u.XXXXXX")" && cp -p "$RS/$u" "$tmp" && mv -f "$tmp" "$UNIT_DIR/$u" || return 1
    done
-    for u in [email protected] "mosaic-bus@$BUSINESS.service.d" "$CONSOLE_UNIT.d"; do
+    for u in "$BUS_TEMPLATE.d" "$BUS_UNIT.d" "$CONSOLE_UNIT.d"; do
        [ -d "$RS/$u" ] || continue
        while IFS= read -r -d '' f; do
            rel="${f#"$RS/$u/"}"
@@ -542,12 +551,12 @@ put_back() {
            tmp="$(mktemp "$UNIT_DIR/$u/.restore.XXXXXX")" && cp -p "$f" "$tmp" && mv -f "$tmp" "$UNIT_DIR/$u/$rel" || return 1
        done < <(find "$RS/$u" -type f -print0)
    done
-    tmp="$(mktemp "$BIN/.mosaic.XXXXXX")" && cp -p "$RS/wrapper" "$tmp" && chmod "$(cat "$RS/WRAPPER_MODE")" "$tmp" && mv -f "$tmp" "$BIN/mosaic" || return 1
-    for u in [email protected] "$CONSOLE_UNIT"; do
+    tmp="$(mktemp "$BIN/.$WRAPPER_NAME.XXXXXX")" && cp -p "$RS/wrapper" "$tmp" && chmod "$(cat "$RS/WRAPPER_MODE")" "$tmp" && mv -f "$tmp" "$BIN/$WRAPPER_NAME" || return 1
+    for u in "$BUS_TEMPLATE" "$CONSOLE_UNIT"; do
        [ "$(sha256sum < "$UNIT_DIR/$u" | cut -d' ' -f1)" = "$(sum_of "$RS" "$u")" ] || return 1
    done
-    [ "$(sha256sum < "$BIN/mosaic" | cut -d' ' -f1)" = "$(sum_of "$RS" wrapper)" ] || return 1
-    [ "$(stat -c %a "$BIN/mosaic")" = "$(cat "$RS/WRAPPER_MODE")" ] || return 1
+    [ "$(sha256sum < "$BIN/$WRAPPER_NAME" | cut -d' ' -f1)" = "$(sum_of "$RS" wrapper)" ] || return 1
+    [ "$(stat -c %a "$BIN/$WRAPPER_NAME")" = "$(cat "$RS/WRAPPER_MODE")" ] || return 1
    systemctl --user daemon-reload || return 1
    say "put back the unit files and the wrapper from $RS"
 }
@@ -604,9 +613,9 @@ lock() {

 instance_busy() {
    local out unit load state rest
-    out="$(systemctl --user list-units --all --no-legend --plain 'mosaic-bus@*.service' 2>/dev/null)" || refuse instance-busy "systemctl --user list-units failed, so the bus state is unknown"
+    out="$(systemctl --user list-units --all --no-legend --plain "$BUS_GLOB" 2>/dev/null)" || refuse instance-busy "systemctl --user list-units failed, so the bus state is unknown"
    while read -r unit load state rest; do
-        [[ "$unit" == mosaic-bus@*.service ]] || continue
+        [[ "$unit" == $BUS_GLOB ]] || continue
        if [ "$unit" = "$BUS_UNIT" ]; then
            case "$state" in activating|deactivating|reloading) refuse instance-busy "$unit is $state" ;; esac
        else
@@ -618,14 +627,17 @@ instance_busy() {
 # install_guard's drop-in scan (bus-service.sh), done before anything stops. A path it can't read
 # refuses here, as install_guard would refuse it after the stop (row 166 item 1).
 drop_in_override() {
-    local paths directory dropdir file content
+    local paths directory dropdir file content glob
+    local -a dropdirs
    paths="$(systemd-analyze --user unit-paths 2>/dev/null)" && [ -n "$paths" ] || refuse drop-in-override "systemd unit paths are unknown"
    while IFS= read -r directory; do
        [ -n "$directory" ] || continue
        case "$directory" in /*) ;; *) refuse drop-in-override "invalid systemd unit path $directory" ;; esac
        [ -e "$directory" ] || [ -L "$directory" ] || continue
        [ -d "$directory" ] && [ -r "$directory" ] && [ -x "$directory" ] || refuse drop-in-override "cannot inspect unit path $directory"
-        for dropdir in "$directory"/mosaic-bus@*.service.d "$directory"/mosaic-.service.d "$directory"/service.d; do
+        dropdirs=()
+        for glob in "${BUS_DROPIN_GLOBS[@]}"; do dropdirs+=("$directory"/$glob); done
+        for dropdir in "${dropdirs[@]}"; do
            [ -e "$dropdir" ] || [ -L "$dropdir" ] || continue
            [ -d "$dropdir" ] && [ -r "$dropdir" ] && [ -x "$dropdir" ] || refuse drop-in-override "cannot inspect drop-ins $dropdir"
            for file in "$dropdir"/*.conf; do
@@ -681,6 +693,7 @@ console_for_target() {
            [ "$PLAN" = 1 ] || usage
            local other=""
            [ "$main" = 7332 ] || other=" and the Console's --port $main"
+            [ "${#INSTANCE_RESERVED[@]}" = 0 ] || other+=" and instance $MOSAIC_INSTANCE's reserved ${INSTANCE_RESERVED[*]}"
            check_refuse tester-port-invalid "--tester-port $TESTER_PORT is not a whole port from 1024 to 65535 other than 7332$other"
        fi
        [ "$supported" = 1 ] || check_refuse tester-port-target "$TO's Console does not support --tester-port"
@@ -690,6 +703,33 @@ console_for_target() {
        DROP_TESTER="--tester-port $inherited"
    fi
    proof_for_target
+    send_for_target
+}
+
+# Row 189 (mos-0972): --no-send drops --send from RUN_CONSOLE, so the unit and the pointer both lose
+# it; without the flag the pointer's --send goes on unchanged. Rollback and pm-on never take it, so
+# they carry the pointer as it is. Sets SEND_PLAN (the plan's send: line) and SEND_STEP.
+send_for_target() {
+    local had=0 i
+    local -a without_send=()
+    for ((i = 0; i < ${#RUN_CONSOLE[@]}; i++)); do
+        if [ "${RUN_CONSOLE[i]}" = --send ]; then had=1; else without_send+=("${RUN_CONSOLE[i]}"); fi
+    done
+    SEND_STEP=""
+    if [ "$NO_SEND" = 1 ]; then
+        RUN_CONSOLE=("${without_send[@]}")
+        if [ "$had" = 1 ]; then
+            SEND_PLAN="send: dropped; --no-send was given"
+            SEND_STEP="drop --send; --no-send was given"
+        else
+            SEND_PLAN="send: off; --no-send was given and the pointer holds no --send"
+            SEND_STEP="--no-send was given and the pointer holds no --send, so there is nothing to drop"
+        fi
+    elif [ "$had" = 1 ]; then
+        SEND_PLAN="send: carried"
+    else
+        SEND_PLAN="send: off"
+    fi
 }

 # Row 187: the row 178 proof pair in RUN_CONSOLE. A new pair replaces the pointer's and goes last;
@@ -783,10 +823,30 @@ proof_file_problem() {
    [ "$uid" = "$(id -u)" ] || echo "is owned by uid $uid, not $(id -u), the uid this script runs as"
 }

+# Row 190: the target Console's --port (7332 when absent) and --tester-port against every other
+# installed Console unit in UNIT_DIR, the default's and each named instance's.
+ports_unclaimed() {
+    local main=7332 i holder
+    local -a ports=()
+    for ((i = 0; i < ${#RUN_CONSOLE[@]}; i++)); do
+        case "${RUN_CONSOLE[i]}" in
+            --port) main="${RUN_CONSOLE[i + 1]:-7332}" ;;
+            --tester-port) ports+=("${RUN_CONSOLE[i + 1]:-}") ;;
+        esac
+    done
+    for i in "$main" "${ports[@]}"; do
+        [[ "$i" =~ ^[0-9]{1,5}$ ]] || continue
+        if holder="$(instance_port_holder "$UNIT_DIR" "$i")"; then
+            check_refuse port-claimed "port $i is taken by $UNIT_DIR/$holder"
+        fi
+    done
+}
+
 # The item 3 checks after the pointer, shared by activate and rollback, for target $TO.
 precheck() {
    check_target
    console_for_target
+    ports_unclaimed
    instance_busy
    drop_in_override
    read_units || refuse unit-flags-drift "cannot read $BUS_UNIT or $CONSOLE_UNIT"
@@ -827,7 +887,7 @@ do_adopt() {
    lock
    [ ! -f "$POINTER" ] || { read_pointer; FROM="$P_COPY"; refuse already-adopted "$POINTER exists (copy $P_COPY)"; }
    local out
-    out="$(scripts/stack-copy.sh check --copies "$COPIES" --bin "$BIN" --business "$BUSINESS" 2>&1)" || refuse check-failed "stack-copy.sh check did not pass:"$'\n'"$out"
+    out="$(scripts/stack-copy.sh check "${INSTANCE_FLAGS[@]}" --copies "$COPIES" --bin "$BIN" --business "$BUSINESS" 2>&1)" || refuse check-failed "stack-copy.sh check did not pass:"$'\n'"$out"
    TO="$(sed -n 's/^bus: //p' <<< "$out")"
    TO="${TO#"$COPIES/"}"
    read_units || refuse check-failed "cannot read $BUS_UNIT or $CONSOLE_UNIT"
@@ -940,11 +1000,13 @@ plan() {
    plan_commits
    [ "$P_PENDING" = 0 ] || echo "pm: the pointer is pending (activate --pm-after-harness); the bus runs without its PM"
    [ "$RUN_PENDING" = 0 ] || echo "pm: the bus starts without --pm and the PM stays pending; next: Jason's plugins set of harness, then pm-on"
-    echo "bus: scripts/bus-service.sh install --copy $TO --copies $COPIES$([ "$RUN_PM" = 0 ] || echo ' --pm') --claude $P_CLAUDE"
+    local flags="${INSTANCE_FLAGS[*]:+${INSTANCE_FLAGS[*]} }"
+    echo "bus: scripts/bus-service.sh install $flags--copy $TO --copies $COPIES$([ "$RUN_PM" = 0 ] || echo ' --pm') --claude $P_CLAUDE"
    [ -z "$DROP_TESTER" ] || echo "drop $DROP_TESTER; the target Console does not support it"
    echo "$PROOF_PLAN"
-    echo "Console: scripts/webui-service.sh install --copy $TO --copies $COPIES${RUN_CONSOLE[*]:+ ${RUN_CONSOLE[*]}}"
-    echo "CLI: scripts/stack-copy.sh wrapper $TO --copies $COPIES --bin $BIN"
+    echo "$SEND_PLAN"
+    echo "Console: scripts/webui-service.sh install $flags--copy $TO --copies $COPIES${RUN_CONSOLE[*]:+ ${RUN_CONSOLE[*]}}"
+    echo "CLI: scripts/stack-copy.sh wrapper $TO $flags--copies $COPIES --bin $BIN"
    local r
    for r in "${PLAN_REFUSE[@]}"; do echo "refuses $r"; done
    [ "${#PLAN_REFUSE[@]}" = 0 ] || exit 3
@@ -956,6 +1018,7 @@ run_steps() {
    capture || refuse capture-failed "could not write the rollback set $RS; nothing was stopped"
    [ -z "$DROP_TESTER" ] || say "drop $DROP_TESTER; the target Console does not support it"
    [ -z "$PROOF_STEP" ] || say "$PROOF_STEP"
+    [ -z "$SEND_STEP" ] || say "$SEND_STEP"
    trap 'after_fail signal' INT TERM HUP
    stop_both || rollback_in_run stop-timeout
    if [ -e "$STORE" ]; then
@@ -1015,7 +1078,7 @@ do_activate() {
    pointer_for_business
    run_pm
    [ "$P_PENDING" = 0 ] || check_refuse pm-pending "the pointer is pending (activate --pm-after-harness); run pm-on or rollback first"
-    if [ "$PLAN" = 1 ]; then check_target; console_for_target; plugin_checks; plan; exit 0; fi
+    if [ "$PLAN" = 1 ]; then check_target; console_for_target; ports_unclaimed; plugin_checks; plan; exit 0; fi
    precheck
    plugin_checks
    new_activation
@@ -1027,7 +1090,7 @@ do_rollback() {
    pointer_for_business
    TO="$(from_log previous)" || refuse no-previous "the log names no earlier copy than $P_COPY"
    run_pm
-    if [ "$PLAN" = 1 ]; then check_target; console_for_target; plugin_checks; plan; exit 0; fi
+    if [ "$PLAN" = 1 ]; then check_target; console_for_target; ports_unclaimed; plugin_checks; plan; exit 0; fi
    precheck
    plugin_checks
    [ "$P_SCHEMA" = "$T_SCHEMA" ] || [ -n "$RESTORE" ] || refuse schema-differs "the store is at $P_SCHEMA and $TO expects $T_SCHEMA; pass --restore ACTIVATION"
@@ -1121,7 +1184,7 @@ do_pm_on() {
    capture || refuse capture-failed "could not write the rollback set $RS; nothing was stopped"
    trap 'pm_on_fail signal' INT TERM HUP
    stop_bus || pm_on_fail stop-timeout
-    scripts/bus-service.sh install --copy "$P_COPY" --copies "$COPIES" --pm --claude "$P_CLAUDE" >> "$STEPS" 2>&1 || pm_on_fail install-bus
+    scripts/bus-service.sh install "${INSTANCE_FLAGS[@]}" --copy "$P_COPY" --copies "$COPIES" --pm --claude "$P_CLAUDE" >> "$STEPS" 2>&1 || pm_on_fail install-bus
    say "installed $BUS_UNIT for $P_COPY with --pm"
    start_bus || pm_on_fail start
    gate "$P_COPY" 1 || pm_on_fail "$GATE"
@@ -1141,7 +1204,7 @@ do_status() {
    open="$(interrupted | paste -sd' ' -)"
    [ -z "$open" ] || echo "interrupted run: $open (started, no final line; Jason or Mos settles it)"
    echo "check:"
-    if scripts/stack-copy.sh check --copies "$COPIES" --bin "$BIN" --business "$BUSINESS" 2>&1 | sed 's/^/  /'; then echo "  result: pass"; else echo "  result: FAIL"; fi
+    if scripts/stack-copy.sh check "${INSTANCE_FLAGS[@]}" --copies "$COPIES" --bin "$BIN" --business "$BUSINESS" 2>&1 | sed 's/^/  /'; then echo "  result: pass"; else echo "  result: FAIL"; fi
    [ -n "$P_COPY" ] || return 0
    echo "bus status:"
    "$COPIES/$P_COPY/scripts/mosaic" bus status 2>&1 | sed 's/^/  /' || true
@@ -1405,6 +1468,7 @@ do_rehearse() {
    local -a reserved=(7332 7333 "$(console_port)")
    for ((i = 0; i < ${#P_CONSOLE[@]}; i++)); do [ "${P_CONSOLE[i]}" != --tester-port ] || reserved+=("${P_CONSOLE[i + 1]:-}"); done
    for i in "${reserved[@]}"; do [ "$((10#$R_PORT))" != "$i" ] || r_abort port-reserved "--port $R_PORT is a live Console port (7332, 7333 and the pointer's: ${reserved[*]:2})"; done
+    if i="$(instance_port_holder "$UNIT_DIR" "$R_PORT")"; then r_abort port-reserved "--port $R_PORT is $UNIT_DIR/$i's Console port"; fi
    r_port_free "$R_PORT" || r_abort port-in-use "127.0.0.1:$R_PORT is in use; the rehearsal takes no other port"
    r_pass port "127.0.0.1:$R_PORT is free"
    case "$R_BACKUP" in /*) R_BK="$R_BACKUP" ;; *) R_BK="$DATA/backups/stack/$R_BACKUP" ;; esac
@@ -1457,6 +1521,9 @@ do_rehearse() {

 # --- Dispatch ---

+# Row 190: --instance NAME may come anywhere; instance.sh takes it out and sets the names.
+instance_args "$@"
+set -- ${INSTANCE_ARGS[@]+"${INSTANCE_ARGS[@]}"}
 [ $# -gt 0 ] || usage
 OP="$1"; shift
 ID=""
@@ -1469,16 +1536,17 @@ esac
 [[ "$BUSINESS" =~ ^[a-z0-9][a-z0-9-]*$ ]] || usage
 parse_opts "$@"
 COPIES_DIR="$COPIES"
+instance_select
 load_config
 DATA="$MOSAIC_DATA_ROOT"
 STATE="$DATA/state"
 POINTER="$STATE/stack-active.json"
 LOG="$STATE/stack-activation-log.jsonl"
 STORE="$DATA/bus/bus.sqlite"
-BUS_UNIT="mosaic-bus@$BUSINESS.service"
+BUS_UNIT="${BUS_TEMPLATE%.service}$BUSINESS.service"
 FROM="" TO="" ACT="" RS="" POST="" BACKUP="" TAKEN="" RESTORED="" STEPS="" COUNT="" UNCLEAN="" FAIL=""
 STORE_SCHEMA="" START_EPOCH="" START_MS=0 GATE="" GATE_WHY="" S_CHANGED=""
-P_COPY="" P_PM=0 P_PENDING=0 P_SCHEMA="" P_CLAUDE="" P_CONSOLE=() RUN_PM=0 RUN_PENDING=0 RUN_CONSOLE=() DROP_TESTER="" PROOF_PLAN="" PROOF_STEP="" PLAN_REFUSE=()
+P_COPY="" P_PM=0 P_PENDING=0 P_SCHEMA="" P_CLAUDE="" P_CONSOLE=() RUN_PM=0 RUN_PENDING=0 RUN_CONSOLE=() DROP_TESTER="" PROOF_PLAN="" PROOF_STEP="" SEND_PLAN="" SEND_STEP="" PLAN_REFUSE=()
 R="" R_RC=0 R_EARLY=() R_BK="" R_HOST_PID="" R_CONSOLE_PID="" R_STARTED="" LIVE_CFG="" LIVE_BIZ=""
 case "$OP" in
    adopt) do_adopt ;;
@@ -151,6 +151,52 @@ else
    FAIL=$((FAIL+1)); echo "${C_FAIL}FAIL${C_RESET} env exports resolve correctly"
 fi

+# --- Q175 phase 1 (#1690), design test 25: the optional console key ---
+# Shape only. The slot path is a FIFO, so a loader that opened the slot would block and the
+# timeout would fail the case; no case reads a slot file.
+mkdir -p "$SANDBOX/secrets/mosaic-stack"
+mkfifo "$SANDBOX/secrets/mosaic-stack/console-sso-test"
+sso_body() {
+    printf '{"configVersion":1,"environment":"development","dataRoot":"%s","execution":{"backend":"docker","provider":"zai","model":"m"},"console":%s}' "$DATA_ROOT" "$1"
+}
+# provider [ALGS] [CLIENT_SECRET]: one provider entry; an empty argument takes the valid value.
+provider() {
+    local algs='["RS256"]' secret='{"slot":"console-sso-test"}'
+    [ -n "${1:-}" ] && algs="$1"
+    [ -n "${2:-}" ] && secret="$2"
+    printf '{"id":"fake","issuer":"https://op.test/app/","clientId":"client-1","clientSecret":%s,"algs":%s,"subjects":[{"sub":"user-1","name":"jason.woltje"}]}' "$secret" "$algs"
+}
+cfg sso-valid.json "$(sso_body '{"sso":{"publicOrigin":"https://console.test","providers":['"$(provider)"']}}')"
+OUT="$(MOSAIC_CONFIG="$SANDBOX/sso-valid.json" timeout 20 $CONFIG_OP validate 2>&1)"
+[ $? -eq 0 ] && printf '%s' "$OUT" | grep -q '"publicOrigin": "https://console.test"'
+check "valid console.sso loads and is in the output" $?
+
+# expect_refusal NAME PATH-IN-MESSAGE BODY: exit 2, and the message names the bad key path.
+expect_refusal() {
+    cfg sso-bad.json "$2"
+    local err rc
+    err="$(MOSAIC_CONFIG="$SANDBOX/sso-bad.json" timeout 20 $CONFIG_OP validate 2>&1 >/dev/null)"
+    rc=$?
+    [ "$rc" -eq 2 ] && printf '%s' "$err" | grep -qF -- "$3"
+    check "$1 (exit $rc)" $?
+}
+expect_refusal "console.sso HS256 alg exits 2 naming the path" \
+    "$(sso_body '{"sso":{"publicOrigin":"https://console.test","providers":['"$(provider '["HS256"]')"']}}')" 'console.sso.providers[0].algs[0] must be one of'
+expect_refusal "console.sso alg none exits 2 naming the path" \
+    "$(sso_body '{"sso":{"publicOrigin":"https://console.test","providers":['"$(provider '["RS256","none"]')"']}}')" 'console.sso.providers[0].algs[1] must be one of'
+expect_refusal "console.sso missing slot field exits 2 naming the path" \
+    "$(sso_body '{"sso":{"publicOrigin":"https://console.test","providers":['"$(provider '' '{}')"']}}')" 'console.sso.providers[0].clientSecret.slot is required'
+expect_refusal "console.sso slot name outside the pattern exits 2 naming the path" \
+    "$(sso_body '{"sso":{"publicOrigin":"https://console.test","providers":['"$(provider '' '{"slot":"../x"}')"']}}')" 'console.sso.providers[0].clientSecret.slot must match'
+expect_refusal "unknown key under console exits 2 naming the path" \
+    "$(sso_body '{"sso":{"publicOrigin":"https://console.test","providers":['"$(provider)"']},"extra":1}')" 'console.extra is not a supported key'
+
+# Without the key: the output is exactly what the loader printed before phase 1 (sage-1340, F2).
+cfg no-console.json '{"configVersion":1,"environment":"development","dataRoot":"'$DATA_ROOT'","execution":{"backend":"docker","provider":"zai","model":"m"}}'
+EXPECTED="$(printf '{\n  "configVersion": 1,\n  "environment": "development",\n  "dataRoot": "%s",\n  "execution": {\n    "backend": "docker",\n    "provider": "zai",\n    "model": "m",\n    "adapter": "pi"\n  }\n}' "$DATA_ROOT")"
+[ "$(MOSAIC_CONFIG="$SANDBOX/no-console.json" timeout 20 $CONFIG_OP validate)" = "$EXPECTED" ]
+check "config without console loads with unchanged output" $?
+
 # --- validation must not modify the file ---
 SUM_INVALID_BEFORE=$(sha256sum "$SANDBOX/invalid.json" | cut -d' ' -f1)
 MOSAIC_CONFIG="$SANDBOX/invalid.json" $CONFIG_OP validate >/dev/null 2>&1
@@ -170,6 +170,10 @@ check "scripts/discord.sh reload without a binding exits 4" $?

 # --- the service unit: rendered from the template, never touching systemd here ---
 UNITS="$SANDBOX/units"
+# Row 190: discord-service.sh reads the selected config first, so these runs name a scratch one
+# that does not exist (the default's names, no data root) instead of ~/.config/mosaic-dev.
+CALLER_MOSAIC_CONFIG="${MOSAIC_CONFIG-}"
+export MOSAIC_CONFIG="$SANDBOX/absent/config.json"
 scripts/discord-service.sh >/dev/null 2>&1
 [ $? -eq 4 ]
 check "scripts/discord-service.sh without a command exits 4" $?
@@ -246,6 +250,7 @@ HOME="$SANDBOX/home" XDG_CONFIG_HOME="$SANDBOX/config-home" PATH="$SANDBOX/fake-
 check "status names the copy from fake systemctl effective cwd" $?
 grep -qF "checkout: $REPO_DIR" "$SANDBOX/install.1" && grep -qF -- '--copy' "$SANDBOX/install.1"
 check "checkout install explicitly recommends --copy" $?
+if [ -n "$CALLER_MOSAIC_CONFIG" ]; then export MOSAIC_CONFIG="$CALLER_MOSAIC_CONFIG"; else unset MOSAIC_CONFIG; fi

 # Offline wrapper entrypoint. Only a synthetic token/binding/config are used.
 node - "$SANDBOX" <<'EOF_OFFLINE'
@@ -49,6 +49,9 @@
 # character set and refused otherwise. --proof-header NAME --proof-file PATH
 # go together under preview; only the path is carried here, never the secret.
 # render checks ownership, mode and location without opening the proof file.
+# --sso (Q175 phase 1, #1690): the Console signs people in itself from
+# console.sso in config.json. It refuses the preview set and the proof pair,
+# and --send takes it in place of the preview set. Nothing secret is carried.
 #
 # There is no start, stop, enable or restart verb. The Console reads the
 # main listener's bus through the human transport; the optional loopback
@@ -62,13 +65,34 @@
 # --no-reload: a unit rewritten under a running Console would take the new
 # ExecStart at its next Restart=on-failure, with nobody starting it.
 #
-# Exit codes: 0 ok, 1 operation failed, 4 usage.
+# --instance NAME (row 190, any position) selects stack instance NAME: the
+# unit is mosaic-webui-NAME.service and sets MOSAIC_CONFIG to
+# ~/.config/mosaic-NAME/config.json, its bus units are mosaic-bus-NAME@,
+# and render and install need --port, which may not be 7330, 7332 or 7333
+# (exit 4, port-reserved). For every instance, install refuses a --port or
+# --tester-port that another installed Console unit in the unit directory
+# already takes (port-claimed). copy refuses --instance (exit 4), as
+# stack-copy.sh copy does: every instance shares the copies. See
+# scripts/instance.sh.
+#
+# Exit codes: 0 ok, 1 operation failed, 3 the data root is claimed by another
+# instance or not claimed (scripts/instance.sh), 4 usage.
 set -euo pipefail
 REPO="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
 TEMPLATE="$REPO/packages/webui/systemd/mosaic-webui.service.in"
-UNIT_NAME="mosaic-webui.service"
-USAGE="usage: scripts/webui-service.sh copy COMMIT [--copies DIR] [--allow-worktree] | render [--copy ID [--copies DIR]] [FLAGS] | install --copy ID [--copies DIR] [--dir DIR] [--no-reload] [--allow-worktree] [FLAGS] | uninstall [--dir DIR] [--no-reload] | status [--dir DIR]
-  FLAGS: [--port N] [--business ID] [--board URL] [--public-host NAME --auth-header HEADER --allow-user ID [--send]] [--tester-port N] [--proof-header NAME --proof-file PATH]
+# shellcheck source=scripts/instance.sh
+. "$REPO/scripts/instance.sh"
+instance_args "$@"
+set -- ${INSTANCE_ARGS[@]+"${INSTANCE_ARGS[@]}"}
+if [ "${1:-}" = copy ] && [ -n "$INSTANCE_FLAG" ]; then
+    echo "webui-service: copy takes no --instance; every instance shares the copies" >&2
+    exit 4
+fi
+instance_select
+UNIT_NAME="$CONSOLE_UNIT"
+BUS_UNIT_PREFIX="${BUS_TEMPLATE%.service}"
+USAGE="usage: scripts/webui-service.sh copy COMMIT [--copies DIR] [--allow-worktree] | [--instance NAME] render [--copy ID [--copies DIR]] [FLAGS] | install --copy ID [--copies DIR] [--dir DIR] [--no-reload] [--allow-worktree] [FLAGS] | uninstall [--dir DIR] [--no-reload] | status [--dir DIR]
+  FLAGS: [--port N] [--business ID] [--board URL] [--sso [--send] | --public-host NAME --auth-header HEADER --allow-user ID [--send]] [--tester-port N] [--proof-header NAME --proof-file PATH]
  --tester-port: 1024..65535, different from --port and never 7332; loopback tester listener.
  --allow-worktree is for the tests only: copy and install otherwise refuse outside the canonical checkout."

@@ -83,6 +107,7 @@ ALLOW_WORKTREE=0
 RELOAD=1
 DIR_FLAGS=0
 PORT=7332
+PORT_SET=0
 TESTER_PORT=""
 TESTER_SET=0
 BUSINESS=""
@@ -91,6 +116,7 @@ PUBLIC_HOST=""
 AUTH_HEADER=""
 ALLOW_USER=""
 SEND=0
+SSO=0
 PROOF_HEADER=""
 PROOF_FILE=""
 PROOF_SET=0
@@ -104,7 +130,7 @@ parse_flags() {
            --copies) [ $# -ge 2 ] || usage; COPIES="$2"; COPY_FLAGS=1; shift 2 ;;
            --allow-worktree) ALLOW_WORKTREE=1; shift ;;
            --no-reload) RELOAD=0; DIR_FLAGS=1; shift ;;
-            --port) [ $# -ge 2 ] || usage; PORT="$2"; SERVE_SET=1; shift 2 ;;
+            --port) [ $# -ge 2 ] || usage; PORT="$2"; PORT_SET=1; SERVE_SET=1; shift 2 ;;
            --tester-port) [ $# -ge 2 ] || usage; TESTER_PORT="$2"; TESTER_SET=1; SERVE_SET=1; shift 2 ;;
            --business) [ $# -ge 2 ] || usage; BUSINESS="$2"; SERVE_SET=1; shift 2 ;;
            --board) [ $# -ge 2 ] || usage; BOARD="$2"; SERVE_SET=1; shift 2 ;;
@@ -114,6 +140,7 @@ parse_flags() {
            --proof-header) [ $# -ge 2 ] || usage; PROOF_HEADER="$2"; PROOF_SET=1; SERVE_SET=1; shift 2 ;;
            --proof-file) [ $# -ge 2 ] || usage; PROOF_FILE="$2"; PROOF_SET=1; SERVE_SET=1; shift 2 ;;
            --send) SEND=1; SERVE_SET=1; shift ;;
+            --sso) SSO=1; SERVE_SET=1; shift ;;
            *) usage ;;
        esac
    done
@@ -122,6 +149,31 @@ parse_flags() {
    [ "$TESTER_SET" = 0 ] || tester_port_ok
 }

+# Row 190: a named instance's Console names its own port, outside the
+# default's ports. Called by render and install only.
+instance_ports_ok() {
+    [ "${#INSTANCE_RESERVED[@]}" -gt 0 ] || return 0
+    [ "$PORT_SET" = 1 ] || { echo "webui-service: stack instance $MOSAIC_INSTANCE needs --port; it has no default port" >&2; exit 4; }
+    local p r
+    for p in "$PORT" ${TESTER_PORT:+"$TESTER_PORT"}; do
+        [[ "$p" =~ ^[0-9]{1,5}$ ]] || continue
+        for r in "${INSTANCE_RESERVED[@]}"; do
+            [ "$((10#$p))" != "$r" ] || { echo "webui-service: port-reserved: $p is reserved for the default instance (${INSTANCE_RESERVED[*]})" >&2; exit 4; }
+        done
+    done
+}
+
+# Row 190: refuse a port another installed Console unit already takes.
+ports_unclaimed() {
+    local p holder
+    for p in "$PORT" ${TESTER_PORT:+"$TESTER_PORT"}; do
+        [[ "$p" =~ ^[0-9]{1,5}$ ]] || continue
+        if holder="$(instance_port_holder "$UNIT_DIR" "$p")"; then
+            die "refusing port-claimed: port $p is taken by $UNIT_DIR/$holder; nothing was changed"
+        fi
+    done
+}
+
 tester_port_usage() {
    echo "webui-service: --tester-port must be 1024..65535, different from --port and never 7332: $TESTER_PORT" >&2
    exit 4
@@ -166,9 +218,13 @@ serve_flags() {
    [ -z "$PUBLIC_HOST" ] || preview=$((preview + 1))
    [ -z "$AUTH_HEADER" ] || preview=$((preview + 1))
    [ -z "$ALLOW_USER" ] || preview=$((preview + 1))
-    # serve refuses --send without the preview set; refuse it here first,
-    # so no unit is written that would only exit 2 at start.
-    [ "$SEND" = 0 ] || [ "$preview" -eq 3 ] || die "--send needs the preview mode (--public-host, --auth-header and --allow-user)"
+    # serve refuses --sso with the preview set or the proof pair, and --send
+    # without --sso or the preview set; refuse them here first, so no unit is
+    # written that would only exit 2 at start.
+    if [ "$SSO" = 1 ] && { [ "$preview" -ne 0 ] || [ "$PROOF_SET" = 1 ]; }; then
+        die "--sso cannot be combined with --public-host, --auth-header, --allow-user or --proof-*"
+    fi
+    [ "$SEND" = 0 ] || [ "$preview" -eq 3 ] || [ "$SSO" = 1 ] || die "--send needs the preview mode (--public-host, --auth-header and --allow-user) or --sso"
    if [ "$preview" -ne 0 ]; then
        [ "$preview" -eq 3 ] || die "--public-host, --auth-header and --allow-user go together: all three or none"
        case "$PUBLIC_HOST" in [A-Za-z0-9]*) ;; *) die "public host must be a hostname, no port or scheme: $PUBLIC_HOST" ;; esac
@@ -201,6 +257,7 @@ serve_flags() {
        { [ "$proof_mode" = 600 ] || [ "$proof_mode" = 400 ]; } && [ "$proof_uid" = "$(id -u)" ] || die "invalid proxy proof file metadata"
        flags="$flags --proof-header $PROOF_HEADER --proof-file $PROOF_FILE"
    fi
+    [ "$SSO" = 0 ] || flags="$flags --sso"
    [ "$SEND" = 0 ] || flags="$flags --send"
    [ "$TESTER_SET" = 0 ] || flags="$flags --tester-port $TESTER_PORT"
    echo "$flags"
@@ -249,7 +306,7 @@ render() {
    local flags
    flags="$(serve_flags)" || exit 1
    [ -z "$COPY_ID" ] || flags="--checkout $REPO $flags"
-    sed -e "s|@REPO@|$root|g" -e "s|@PATH@|$path|g" -e "s|@NODE@|$node|g" -e "s|@FLAGS@|$flags|g" "$TEMPLATE"
+    sed -e "s|@REPO@|$root|g" -e "s|@PATH@|$path|g" -e "s|@NODE@|$node|g" -e "s|@FLAGS@|$flags|g" "${INSTANCE_SED[@]}" "$TEMPLATE"
 }

 # The unit's active state from list-units, printed when it is anything but
@@ -269,16 +326,17 @@ running() {
 # only with a bus on that same copy: install refuses unless every bus unit
 # it would call has an ExecStart path inside the copy. With --business the
 # unit is [email protected]; without it, every mosaic-bus@ unit systemd
-# has loaded, and none loaded refuses. Like the state read, a failed call
+# has loaded, and none loaded refuses. A named instance reads its own
+# mosaic-bus-NAME@ units only. Like the state read, a failed call
 # refuses with one line.
 bus_on_copy() {
    local copy="$1" units unit out load paths p working
    if [ -n "$BUSINESS" ]; then
-        units="mosaic-bus@$BUSINESS.service"
+        units="$BUS_UNIT_PREFIX$BUSINESS.service"
    else
-        out="$(systemctl --user list-units --all --no-legend --plain 'mosaic-bus@*.service' 2>/dev/null)" || die "refusing: systemctl --user list-units --all --no-legend --plain mosaic-bus@*.service failed, so the bus unit is unknown; nothing was changed"
-        units="$(printf '%s\n' "$out" | awk '$1 ~ /^mosaic-bus@.+\.service$/ {print $1}')"
-        [ -n "$units" ] || die "refusing: no mosaic-bus@ unit is loaded, and the Console on the copy $copy needs its bus on that copy; name the business with --business ID"
+        out="$(systemctl --user list-units --all --no-legend --plain "$BUS_GLOB" 2>/dev/null)" || die "refusing: systemctl --user list-units --all --no-legend --plain $BUS_GLOB failed, so the bus unit is unknown; nothing was changed"
+        units="$(printf '%s\n' "$out" | awk -v p="$BUS_UNIT_PREFIX" 'index($1, p) == 1 && length($1) > length(p) + 8 && substr($1, length($1) - 7) == ".service" {print $1}')"
+        [ -n "$units" ] || die "refusing: no $BUS_UNIT_PREFIX unit is loaded, and the Console on the copy $copy needs its bus on that copy; name the business with --business ID"
    fi
    for unit in $units; do
        out="$(systemctl --user show "$unit" -p LoadState -p WorkingDirectory -p ExecStart 2>/dev/null)" || die "refusing: systemctl --user show $unit failed, so the bus unit is unknown; nothing was changed"
@@ -298,13 +356,15 @@ install_unit() {
    parse_flags "$@"
    canonical
    [ -n "$COPY_ID" ] || die "install needs --copy ID, a copy made with: scripts/webui-service.sh copy COMMIT"
+    instance_ports_ok
    local unit
    unit="$(render)" || exit 1
+    ports_unclaimed
    bus_on_copy "$COPIES/$COPY_ID"
    # N1: a running unit would take the new ExecStart at its next restart.
    local state
    state="$(running)" || exit 1
-    [ -z "$state" ] || die "refusing: $UNIT_NAME is running ($state); Jason or Mos stops it first (systemctl --user stop mosaic-webui), then install, then start it"
+    [ -z "$state" ] || die "refusing: $UNIT_NAME is running ($state); Jason or Mos stops it first (systemctl --user stop ${UNIT_NAME%.service}), then install, then start it"
    mkdir -p "$UNIT_DIR"
    local target="$UNIT_DIR/$UNIT_NAME" tmp
    tmp="$(mktemp "$UNIT_DIR/.$UNIT_NAME.XXXXXX")"
@@ -326,11 +386,11 @@ install_unit() {
 this script starts nothing: the Console holds the human's capability. Jason
 starts and restarts it, or Mos under lead decision 102 (sends then enter the
 trail as Jason); no other agent does:
-  systemctl --user enable --now mosaic-webui      start now and at login
-  systemctl --user status mosaic-webui
-  journalctl --user -u mosaic-webui -f            the Console's log
-  systemctl --user stop mosaic-webui              SIGTERM; restartable
-  scripts/webui-service.sh status                 unit state and /healthz
+  systemctl --user enable --now ${UNIT_NAME%.service}      start now and at login
+  systemctl --user status ${UNIT_NAME%.service}
+  journalctl --user -u ${UNIT_NAME%.service} -f            the Console's log
+  systemctl --user stop ${UNIT_NAME%.service}              SIGTERM; restartable
+  scripts/webui-service.sh ${INSTANCE_FLAGS[*]:+${INSTANCE_FLAGS[*]} }status                 unit state and /healthz
 survive logout and reboot only with lingering on: loginctl enable-linger ${USER:-$(id -un)}
 MSG
 }
@@ -342,7 +402,7 @@ uninstall_unit() {
    # N3: checked with --no-reload too, which skips only daemon-reload.
    local state
    state="$(running)" || exit 1
-    [ -z "$state" ] || die "refusing: $UNIT_NAME is still running ($state); Jason or Mos stops it first (systemctl --user stop mosaic-webui)"
+    [ -z "$state" ] || die "refusing: $UNIT_NAME is still running ($state); Jason or Mos stops it first (systemctl --user stop ${UNIT_NAME%.service})"
    if [ -f "$target" ]; then
        rm -f "$target"
        echo "removed: $target"
@@ -385,14 +445,17 @@ status_unit() {
    else
        echo "copy: none; the unit runs from $wd"
    fi
-    # render puts --send after the allowed user and optional proof pair,
-    # before the tester port. The allowed user
+    # render puts --send after the allowed user and optional proof pair, or
+    # after --sso, before the tester port. The allowed user
    # starts with a letter or digit (N5), so it is never the value --send.
-    if grep -Eq '^ExecStart=.* --allow-user [^ ][^ ]*( --proof-header [^ ]+ --proof-file /[^ ]+)? --send( --tester-port [0-9]+)?$' "$target"; then
+    if grep -Eq '^ExecStart=.*( --allow-user [^ ][^ ]*( --proof-header [^ ]+ --proof-file /[^ ]+)?| --sso) --send( --tester-port [0-9]+)?$' "$target"; then
        echo "send: on (--send; human messages to roles)"
    else
        echo "send: off (read-only)"
    fi
+    if grep -Eq '^ExecStart=.* --sso( --send)?( --tester-port [0-9]+)?$' "$target"; then
+        echo "sign-in: the Console's own (--sso)"
+    fi
    local tester_port
    tester_port="$(sed -n 's/^ExecStart=.* --tester-port \([0-9][0-9]*\)$/\1/p' "$target")"
    if [ -n "$tester_port" ]; then
@@ -426,6 +489,7 @@ case "$cmd" in
        parse_flags "$@"
        [ "$DIR_FLAGS" = 0 ] && [ "$ALLOW_WORKTREE" = 0 ] || usage
        { [ -n "$COPY_ID" ] || [ "$COPY_FLAGS" = 0 ]; } || usage
+        instance_ports_ok
        render ;;
    install) install_unit "$@" ;;
    uninstall) uninstall_unit "$@" ;;
Author	SHA1	Message	Date
jason.woltje	df65a3d4c8	stack: row 190 round 3 (#1688 ): rebased on row 192 (Q175 SSO), the loader's bootstrap, selected and loadSelected await row 192's async load inside the Failure try; T-I3 checks a named --sso render carries --sso and MOSAIC_CONFIG (Filbert 29685 note 4)	2026-10-20 16:32:05 -05:00
jason.woltje	cdac7ba92b	stack: row 190 round 2 (#1688 ): T56 after row 189's T55, N1 copy and usage, N3 Console comment, N5 and N6 Filbert's round 1 (comment 29634) and Sage's N3 ruling (sage-1474). Row 189 also named a test T55, so row 190's is T56. webui-service.sh copy refuses --instance like stack-copy.sh copy; TOOLS.md shows --instance on the bus and discord usage. A named Console unit's comment names MOSAIC_CONFIG, and the default keeps the template's line. check --instance needs the wrapper's MOSAIC_CONFIG line. TOOLS.md says an existing directory keeps its mode.	2026-10-20 16:30:41 -05:00
jason.woltje	ab1d2ee9e6	stack: several Mosaic Stack instances on one host (row 190, #1688 ) --instance NAME on the shell entry points through scripts/instance.sh; per-instance config, data root and marker, units, wrapper and ports; the claim checks in mosaic-config.mjs; the guard protects every instance's config and data root. Brief blob `4e8f1e0528`, design agents/darkwing/work/queue-190/DESIGN.md rev 3 (Filbert approved).	2026-10-20 16:30:34 -05:00
jason.woltje	176a6bf4b9	sessions: Filbert row 190 manifest round 2 CHANGES (base drift on row 192)	2026-10-20 16:29:20 -05:00
jason.woltje	5b8def2f14	plans: Case 2 row briefs from Gosalyn's `eac92d956` (design r11, approved webby-0038: C2-13 split into C2-13a unit render and host precheck and C2-13b install script and library precheck, C2-04 owner Herb, Console unit without [Install] per mos-1097)	2026-10-20 16:22:47 -05:00
jason.woltje	4429a104f6	webui: Q175 phase 1, the Console verifies SSO itself under --sso, OIDC RP with oauth4webapi 3.8.8 (row 192, #1690 ) Squash of Launchpad's launchpad/row192 53bb59462..37582e820, manifest round 2 6f8cee147713c53652b58d47c5efd15ed47da1efbef6a126464857269b0b7787 (18 paths). Sage's gate on `088087ac9`: package suites 2758 pass 0 fail, scripts/test-*.sh 429 pass 0 fail; mutants 22 of 23 killed, #23 (second origin check) declared equivalent by Launchpad (sage-1407). New dependency oauth4webapi 3.8.8: the canonical checkout and any stack copy need npm ci. No live change; the live re-pin is a window with Mos (mos-1099 item 3).	2026-10-20 16:21:29 -05:00
jason.woltje	32b54ac3b0	plans: Case 2 row briefs from Gosalyn's `51006710a` (webby-0034 N1/N2 and webby-0035: row A README :711 one line per variable, C2-13 owns README :713 and says the precheck prints only variable names)	2026-10-20 15:57:07 -05:00
jason.woltje	6025ddd9cf	plans: Case 2 row briefs from Gosalyn's `a2d94b2c2` (Webby r9 notes, webby-0032: row A README line on claude-session.env and the dist/providers/data/zai.json path, C2-13 XDG_DATA_HOME precheck and last-assignment-wins key file parse)	2026-10-20 15:55:52 -05:00
jason.woltje	ecbfd6deb6	plans: Case 2 row briefs from Gosalyn's `29e85196b` (design r9 for mos-1090: row A out of scope points at design 10 step 2d, C2-13 precheck checks the hub key file by name and mode, claude marker check only for claude-code harness, EnvironmentFile= fixed in case2-unit.sh)	2026-10-20 15:44:09 -05:00
jason.woltje	0498c0613f	agents: Gosalyn seat dir, README from gosalyn/case2-design, so Case 2 rows can name the seat as owner (#416 )	2026-10-20 15:43:18 -05:00
jason.woltje	49d1f3a231	plans: Case 2 slice row briefs plus rows A and B, from Gosalyn's `f325657c7` on gosalyn/case2-design (#416 , design r8, C2-13 copy id and profile asks for row 195, C2-20 count-only note, row A ZAI_API_KEY per mos-1086/mos-1089, row B #428 after 10-27)	2026-10-20 15:41:39 -05:00
jason.woltje	628e2ca5cd	sessions: Filbert row 190 manifest round 1 CHANGES (base drift on row 189)	2026-10-20 15:40:15 -05:00
jason.woltje	088087ac96	queue: revs 2248-2361+. Sage: rows 210 (#424 host access, Gizmoduck) and 211 (#426 force-push guard, Rocko) added and briefed; row 195 re-briefed to the Case 1 install on .53; review requests for 200 r1/r2 and 202; plus earlier Sage revs. Other seats' revs: Launchpad 2254, 2283-2284, 2286, 2311-2313, 2328-2329, 2344, 2347-2348 (rows 192/200); Honker 2255; Morgana 2257, 2320, 2326-2327 (row 204); Gander 2262; Herb 2265; Dewey 2268; Bushroot 2273; Megavolt 2276; Webby 2303, 2316, 2339, 2355 (row 192/200 verdicts); Gizmoduck 2304, 2318-2319 and the row 210 claim (rows 201/210); Quackerjack 2317, 2341-2342 (row 202); Duckworth 2323, 2335, 2353 (rows 201/204/202 verdicts); Darkwing 2354, 2357 (row 190 in-review)	2026-10-20 15:34:55 -05:00
jason.woltje	a0fbefd48d	plans: pre-push force-push hook and failing busy check brief (Vikunja #426 , mos-1078, mos-1083; owner Rocko, reviewer Dewey)	2026-10-20 15:31:17 -05:00
jason.woltje	f24f2cd40d	plans: row 195 brief becomes the Case 1 install on 10.1.1.53 (Q181 hosts, Q182/Q183 recorded acceptance, Q185 existing account, chained on rows 190 and C2-13; ops-01 root steps under #423 step 1; sage-1439)	2026-10-20 15:24:33 -05:00
jason.woltje	9ba31b5b3f	agents: Honker's PRD 1.7 draft r2 on refactor for the prd.approve raise (`11cb0423b`, sha256 e896746df595d1b5155130ca163fbf63b0dc38a87a8dd154af77f1a6d1328647, Duckworth approved duckworth-0039, Vikunja #420 )	2026-10-20 15:20:37 -05:00
jason.woltje	9db578ff54	plans: agent host access with sudo through the credential store brief (#1707 , Vikunja #424 , Q183/Q184, chained on row 199)	2026-10-20 15:09:59 -05:00
jason.woltje	8eb9ddd12c	plans: FED R8 brief to r4.11 (`b93f098f0`, recorded acceptance, Duckworth N1/N2, #416 date), R5 context source (sage-1419), 193a makes covers level required (duckworth-0033 N1)	2026-10-20 15:06:22 -05:00
jason.woltje	ae3c36f248	agents: Gizmoduck seat dir and roster row (FED R1 owner, #414 )	2026-10-20 14:42:15 -05:00
jason.woltje	a2af7ab495	plans: FED R1, R5, R2 and R8 briefs (#414 , r4.9 `a1daa3c07`) and row 193a-d build briefs (#1691 ); Quackerjack seat dir and roster row	2026-10-20 14:41:03 -05:00
jason.woltje	aa1bd209e3	gate-lane: row 189 gate timing table for row 197 (Herb)	2026-10-20 14:25:17 -05:00
jason.woltje	ace27dc5eb	row 189 (#1687 ): stack-release.sh activate --no-send drops the Console's --send (Sage; Dewey approve 29485; Sage gate passed)	2026-10-20 14:21:56 -05:00
jason.woltje	a4a42dbac2	plans: stack-release --sso brief (#1698 , Launchpad, reviewer Webby, row 192 F3; chained on 192)	2026-10-20 14:18:08 -05:00
jason.woltje	a31f1a0f8b	plans: row 198 brief records Mos's call, in-process board reads behind the Console's auth (mos-1019)	2026-10-20 14:17:03 -05:00
jason.woltje	992650232f	plans: agent credentials and git identity brief (MVP T1 item 6, #1697 , Megavolt, reviewer Duckworth); Megavolt seat dir	2026-10-20 14:14:33 -05:00