row 202 round 2: candidate manifest CANDIDATE.sha256 (48a3fb96e, six digests)

- Lock: a dead-pid, empty or unreadable lock refuses and names the path (and pid); a human removes it. No reclaim, so the reclaim race is gone.
- writeAtomic takes the fs calls through deps.fs; a failed write removes its temp file and leaves the old bytes.
- A BusinessError from loadAccess or loadBusiness exits 3 with the file and key path; no stack trace.
- contextFor is built after the agent and tester refusals and the human proof.
- Tests: 21 in access.test.mjs, single file green. New: dead-pid refuses, failed rename, 0664 file, refusal before context.

agents/gizmoduck/work/queue-201/BUILD.md

@@ -0,0 +1,100 @@
+# Row 201 round 1 (#1699): FED R1, the access.json loader and validator
+
+Gizmoduck, 2026-10-20. Reviewer Duckworth, gate owner Sage. Federation design #414.
+
+- Brief: `docs/plans/2026-10-20_federation-r1-r2-r5.md`, section "Brief: FED R1", at a2af7ab49.
+- Design: `agents/gizmoduck/work/federation/DESIGN.md` section 3.5, r4.9 a1daa3c07 on
+  `gizmoduck/federation-design`.
+- Base: ae3c36f24 (`origin/refactor` when I branched, contains the brief). Branch `gizmoduck/fed-r1`.
+- Candidate: the commit that adds this file. `candidate-manifest.sha256` lists the three code files.
+
+## Interface
+
+This is what R5 and row 193a build against. Any change to it in review goes to Sage before it lands.
+Morgana confirmed it (morgana-0014) and Sage accepted it with `ssoSubjects` required (sage-1399). Sage
+relays it to Quackerjack.
+
+| Export | Shape |
+|--------|-------|
+| `LEVELS` | frozen `["collaborator"]`, the one allowed level set. 193a widens it with the single line `["collaborator", "viewer"]` |
+| `accessFilePath(dir = configDir())` | `<dir>/access.json` |
+| `checkAccess(doc, { providers, peers, businesses, ssoSubjects })` | pure, returns a frozen deep copy, throws `BusinessError` exit 2 naming the key path |
+| `loadAccess(file, context, { uid = process.getuid() } = {})` | one no-follow read through `readJsonFile`, then the stat checks, then `checkAccess`. `uid` is a test seam |
+| `covers(grant, { business, project, instance }, now, { level } = {})` | boolean. `now` must be a valid `Date`, otherwise TypeError |
+
+The context: `providers` is an array of provider ids, `peers` an array of peer ids (never `local`),
+`businesses` maps a business id to `{ human, instances }`, and `ssoSubjects` is an array of
+`{ provider, sub }`, the owner's `console.sso.subjects`. A missing or malformed context refuses.
+All four are exported from `src/index.mjs` too.
+
+## Rules, code and tests
+
+DESIGN 3.5 rule, where `access.mjs` enforces it, and the test that shows the refusal names the key path.
+
+| 3.5 rule | access.mjs | access.test.mjs test | Mutant |
+|----------|-----------|----------------------|--------|
+| regular file, not a symlink | 167 (`readJsonFile`, util.mjs:66-89) | "loadAccess refuses a missing file, a symlink and a directory" | M03 |
+| owned by the instance's uid | 168 | "loadAccess refuses another owner and group or other write" | M01 |
+| no group or other write | 169 | same | M02 |
+| unknown keys refuse | 147, 71, 83, 121 | "top level", "users: unknown keys", "users: subjects", "grants: unknown keys" | M05 M10 M16 M22 |
+| `accessVersion` is 1 | 148 | "top level" | M06 |
+| `revision` positive integer | 149 | "top level" | M07 |
+| user id matches the id rule | 72 | "users: unknown keys and the id rule" | M11 |
+| never `human` or `tester` | 73 | "users: human, tester and any business's human" | M12 |
+| never any business's `human` | 74 | same, both businesses | M13 |
+| provider is a given provider | 84-86 | "users: subjects, provider, sub" | M17 |
+| a pair appears once in the file | 90 | same, within one user and across two | M20 |
+| a pair is never in `console.sso.subjects` | 89 | same | M19 |
+| `home` is a given peer or `local` | 75-77 | "users: home is a given peer or local" | M14 |
+| grant names a declared business | 126-128 | "grants: unknown keys, id, user and business" | M26 |
+| `projects` is `["*"]` or UUIDs | 98-107, 130-132 | "grants: projects" | M27 M28 M29 M30 |
+| `instances` is `["*"]` or declared instances | 98-107, 133-135 | "grants: instances" | M31 |
+| `level` is `collaborator` | 136 | "grants: any level other than collaborator" (missing, null, wrong case) | M32 |
+| `expires` optional ISO time | 111-117, 137 | "grants: expires is optional ISO time" | M33 M34 |
+| past `expires` is absent | covers 179 | "covers: an expired grant doesn't match, at and after the instant" | M38 M39 |
+
+`covers`: `*` and listed ids match (180-182), an unlisted project, instance or business doesn't, an
+expired grant doesn't (179), and a level filter rejects another level (183). Mutants M38 to M44.
+
+## Deviations from the brief
+
+1. Expiry. The brief's test list says expiry refuses. DESIGN 3.5 line 257 says a grant past `expires` is
+   treated as absent. Sage ruled the design wins (sage-1399), so a past `expires` passes `checkAccess`
+   and `covers` returns false at and after the instant. A malformed `expires` still refuses.
+2. The brief lists "a grant disjoint from the given subjects". 3.5 has no rule that ties a grant to a
+   subject, and a grant names a user, not a subject. I read it as the 3.5 lines 248-249 subject rules:
+   a `(provider, sub)` pair that is also in `ssoSubjects` refuses, and so does a pair that appears twice.
+   Duckworth, say if you meant something else.
+
+## Rules I added beyond 3.5
+
+Each one is fail closed and has a test and a mutant.
+
+- User ids and grant ids are unique (154, 123; M21, M24). A grant's `user` names a user in the file
+  (125; M25). Without these, a grant could point at nobody or two users could share an id.
+- `projects` and `instances` are non-empty, distinct, and `*` never mixes with ids (98-106).
+- `expires` must be UTC with a `Z` and must round-trip (`2026-02-30T00:00:00Z` refuses). `Date.parse`
+  accepts that date and rolls it to March 2, so the regex alone wasn't enough.
+- The context is checked too (43-67; M35 to M37). `peers` can't name `local`, because that would make a
+  peer user look local.
+- `covers` throws a TypeError for a `now` that isn't a valid Date (M44), since a bad clock would
+  otherwise make every grant look unexpired.
+
+## Checks
+
+- `node --test packages/business/tests/access.test.mjs`: 24 pass, 0 fail (single file, no slot).
+- Morgana's `access-levels.test.mjs` at 08bb4d827, as a cross-check, not part of the candidate. On this
+  candidate it passes 3 of 4, and the one failure is the viewer case 193a adds. In a scratch copy with
+  `LEVELS` widened to `["collaborator", "viewer"]` it passes 4 of 4.
+- `mutants.py`: 44 mutants, one per refusal and covers branch. All 44 anchors match once and every
+  mutant passes `node --check`. **Not run yet**: mutants need Sage's slot. Run as
+  `python3 -I agents/gizmoduck/work/queue-201/mutants.py <checkout> <empty scratch dir>`. It runs a control
+  first, puts each run in its own process group with a 60 s timeout, and exits 1 if any mutant survives.
+- `node tools/unslop-hook/unslop-check.js` is clean on all three code files and this file.
+- No test reads or pins `src/index.mjs` by hash (grep of packages/*/tests and scripts/test-*.sh).
+- Not run: the business suite and `scripts/test-*.sh`. Both need Sage's slot.
+
+## Boundaries kept
+
+Nothing touched `~/.mosaic-dev`, `~/.config/mosaic-dev`, the live units or any access.json. Tests write
+only under `mkdtemp` scratch dirs.

agents/gizmoduck/work/queue-201/base.txt

@@ -0,0 +1 @@
+ae3c36f24883e870541158d3ade1f5d3ef2ab856

agents/gizmoduck/work/queue-201/candidate-manifest.sha256

@@ -0,0 +1,3 @@
+74ac7e9ed38c230e60e7f7ece373104446c362b6fce0a4f92ca2210a981dc4f4  packages/business/src/access.mjs
+7ee59b6e792fb47048fd06d227b65467ef71dabfcbdabdc0527b780656323d20  packages/business/src/index.mjs
+3bec097f55909b31faf2bbc62c81e1d4d0290f50e696d3d3d367e77d82c5b238  packages/business/tests/access.test.mjs

agents/gizmoduck/work/queue-201/mutants.py

@@ -0,0 +1,127 @@
+#!/usr/bin/env python3
+"""Row 201 (FED R1) mutants: one per refusal in packages/business/src/access.mjs.
+
+Usage: mutants.py <checkout> <scratch-dir>
+
+Copies packages/business and packages/plugins from <checkout> into
+<scratch-dir>, applies one mutant at a time (each anchor must match exactly
+once), runs `node --test tests/access.test.mjs` in its own process group with
+a timeout, and expects it to fail. Prints one line per mutant and exits 1 if
+any survives, an anchor misses, or the unmutated control fails. Needs Sage's
+slot. Writes nothing outside <scratch-dir>.
+"""
+import os, shutil, signal, subprocess, sys
+
+MUTANTS = [
+    # loadAccess file checks
+    ("M01 owner check", 'if (stat.uid !== uid) refuse(', 'if (false) refuse('),
+    ("M02 group/other write check", 'if ((stat.mode & 0o022) !== 0) refuse(`access file', 'if (false) refuse(`access file'),
+    ("M03 one-fd nofollow read", 'const document = readJsonFile(file, "access file", (stat) => {',
+     'const document = JSON.parse(readFileSync(file, "utf8")); ((stat) => {'),
+    # top level
+    ("M04 document object", 'if (!isPlainObject(document)) refuse("access file must be a JSON object");', ''),
+    ("M05 top unknown keys", 'rejectUnknownKeys(document, ["accessVersion", "revision", "users", "grants"], "access file");', ''),
+    ("M06 accessVersion", 'if (document.accessVersion !== 1) refuse(', 'if (false) refuse('),
+    ("M07 revision", 'requirePositiveInt(document.revision, "revision");', ''),
+    ("M08 users array", 'requireArray(document.users, "users").forEach(', '(document.users ?? []).forEach('),
+    ("M09 grants array", 'requireArray(document.grants, "grants").forEach(', '(document.grants ?? []).forEach('),
+    # users
+    ("M10 user unknown keys", 'rejectUnknownKeys(user, ["id", "home", "subjects"], at);', ''),
+    ("M11 user id rule", 'requireId(user.id, `${at}.id`);', ''),
+    ("M12 human/tester", 'if (RESERVED_USERS.includes(user.id)) refuse(', 'if (false) refuse('),
+    ("M13 business human", 'if (humans.has(user.id)) refuse(', 'if (false) refuse('),
+    ("M14 home", 'if (user.home !== LOCAL_HOME && !ctx.peers.has(user.home)) {', 'if (false) {'),
+    ("M15 subjects non-empty", 'if (subjects.length === 0) refuse(', 'if (false) refuse('),
+    ("M16 subject unknown keys", 'rejectUnknownKeys(s, ["provider", "sub"], sat);', ''),
+    ("M17 provider", 'if (typeof s.provider !== "string" || !ctx.providers.has(s.provider)) {', 'if (false) {'),
+    ("M18 sub", 'requireText(s.sub, `${sat}.sub`);', ''),
+    ("M19 owner subject", 'if (ctx.owners.has(key)) refuse(', 'if (false) refuse('),
+    ("M20 duplicate subject", 'if (seenSubjects.has(key)) refuse(', 'if (false) refuse('),
+    ("M21 duplicate user id", 'if (users.has(user.id)) refuse(', 'if (false) refuse('),
+    # grants
+    ("M22 grant unknown keys", 'rejectUnknownKeys(grant, ["id", "user", "business", "projects", "instances", "level", "expires"], at);', ''),
+    ("M23 grant id rule", 'requireId(grant.id, `${at}.id`);', ''),
+    ("M24 duplicate grant id", 'if (seenGrants.has(grant.id)) refuse(', 'if (false) refuse('),
+    ("M25 grant user", 'if (typeof grant.user !== "string" || !users.has(grant.user)) refuse(', 'if (false) refuse('),
+    ("M26 grant business", 'if (typeof grant.business !== "string" || !ctx.businesses.has(grant.business)) {', 'if (false) {'),
+    ("M27 scope non-empty", 'if (list.length === 0) refuse(`${where} must not be empty`);', ''),
+    ("M28 scope * alone", 'if (list.length !== 1) refuse(', 'if (false) refuse('),
+    ("M29 scope duplicate", 'if (seen.has(entry)) refuse(', 'if (false) refuse('),
+    ("M30 project UUID", 'if (typeof p !== "string" || !UUID.test(p)) refuse(', 'if (false) refuse('),
+    ("M31 declared instance", 'if (typeof x !== "string" || !business.instances.has(x)) refuse(', 'if (false) refuse('),
+    ("M32 level", 'if (!LEVELS.includes(grant.level)) refuse(', 'if (false) refuse('),
+    ("M33 expires format", 'if (typeof value !== "string" || !ISO_TIME.test(value) || Number.isNaN(Date.parse(value))) {', 'if (typeof value !== "string") {'),
+    ("M34 expires real time", 'if (iso.slice(0, 19) !== value.slice(0, 19)) refuse(', 'if (false) refuse('),
+    # context
+    ("M35 context unknown keys", 'rejectUnknownKeys(context, ["providers", "peers", "businesses", "ssoSubjects"], where);', ''),
+    ("M36 context peers local", 'if (peers.has(LOCAL_HOME)) refuse(', 'if (false) refuse('),
+    ("M37 context ssoSubjects array", 'requireArray(context.ssoSubjects, `${where}.ssoSubjects`).forEach(', '(context.ssoSubjects ?? []).forEach('),
+    # covers
+    ("M38 covers expiry", 'if (grant.expires !== undefined && now.getTime() >= Date.parse(grant.expires)) return false;', ''),
+    ("M39 covers expiry boundary", 'now.getTime() >= Date.parse(grant.expires)', 'now.getTime() > Date.parse(grant.expires)'),
+    ("M40 covers business", 'if (grant.business !== business) return false;', ''),
+    ("M41 covers project", 'if (!(grant.projects[0] === ALL || grant.projects.includes(project))) return false;', ''),
+    ("M42 covers instance", 'if (!(grant.instances[0] === ALL || grant.instances.includes(instance))) return false;', ''),
+    ("M43 covers level", 'if (level !== undefined && grant.level !== level) return false;', ''),
+    ("M44 covers now check", 'if (!(now instanceof Date) || Number.isNaN(now.getTime())) throw', 'if (false) throw'),
+]
+
+TIMEOUT = 60
+
+
+def run(cwd):
+    proc = subprocess.Popen(["node", "--test", "tests/access.test.mjs"], cwd=cwd,
+                            stdout=subprocess.PIPE, stderr=subprocess.STDOUT, start_new_session=True)
+    try:
+        out, _ = proc.communicate(timeout=TIMEOUT)
+    except subprocess.TimeoutExpired:
+        os.killpg(proc.pid, signal.SIGKILL)
+        proc.communicate()
+        return None, "timeout"
+    return proc.returncode, out.decode(errors="replace")
+
+
+def main():
+    if len(sys.argv) != 3:
+        sys.exit("usage: mutants.py <checkout> <scratch-dir>")
+    checkout, scratch = (os.path.abspath(a) for a in sys.argv[1:])
+    if not os.path.isfile(os.path.join(checkout, "packages/business/src/access.mjs")):
+        sys.exit(f"no packages/business/src/access.mjs under {checkout}")
+    if os.path.exists(scratch) and os.listdir(scratch):
+        sys.exit(f"scratch dir not empty: {scratch}")
+    for pkg in ("business", "plugins"):
+        shutil.copytree(os.path.join(checkout, "packages", pkg), os.path.join(scratch, "packages", pkg))
+    pkg = os.path.join(scratch, "packages/business")
+    target = os.path.join(pkg, "src/access.mjs")
+    original = open(target).read()
+
+    code, out = run(pkg)
+    if code != 0:
+        print(out)
+        sys.exit(f"control failed (exit {code}): the unmutated tests must pass")
+    print("control: pass")
+
+    bad = 0
+    for name, old, new in MUTANTS:
+        n = original.count(old)
+        if n != 1:
+            print(f"{name}: ANCHOR {n}")
+            bad += 1
+            continue
+        mutated = original.replace(old, new)
+        if name.startswith("M03"):
+            mutated = 'import { readFileSync } from "node:fs";\n' + mutated
+        open(target, "w").write(mutated)
+        code, _ = run(pkg)
+        open(target, "w").write(original)
+        if code == 0:
+            print(f"{name}: SURVIVED")
+            bad += 1
+        else:
+            print(f"{name}: killed ({'timeout' if code is None else f'exit {code}'})")
+    print(f"mutants {len(MUTANTS)}, not killed {bad}")
+    sys.exit(1 if bad else 0)
+
+
+if __name__ == "__main__":
+    main()

agents/quackerjack/work/queue-202/BUILD.md

@@ -0,0 +1,126 @@
+# Row 202 BUILD: FED R5, `mosaic access list|grant|revoke`
+
+Quackerjack, 2026-10-20. Plan: `PLAN.md` (commit 2d0aa2937). Manifest: `MANIFEST.md` in this directory.
+Brief: `docs/plans/2026-10-20_federation-r1-r2-r5.md`, "Brief: FED R5". Reviewer Duckworth. Gate owner Sage.
+
+## What was built
+
+- `packages/cli/src/access.mjs`: the three verbs, the human proof, the context (`accessContextFor`), the
+  atomic write, the lock and the receipt.
+- `packages/cli/src/cli.mjs`: routes `access` to `accessCommand`.
+- `scripts/mosaic`: sends `access` to the CLI.
+- `packages/cli/README.md`: the verbs, the human proof, the lock, the `instances` limit, the removal order,
+  and the limits on peers and subjects.
+- `packages/cli/tests/access.test.mjs`: 21 tests (round 2; 18 in round 1). Single file, green on this branch.
+
+R1 (`packages/business/src/access.mjs`) is merged in unchanged at 80fe31071, the Duckworth-approved
+candidate. 44e36fc4c, the next commit on that branch, only removes a stray pyc file.
+
+## The lock file (not in PLAN.md; added at Sage's request)
+
+- Path: `<configDir>/access.json.lock`, the access file's path plus `.lock`. Mode 0600.
+- Created with `O_EXCL` (`wx`). The holder writes its pid and a newline into it, then holds it for the
+  read, the check, the temp write and the rename. It is removed in a `finally`.
+- A second writer that finds the lock reads the pid. If the pid is alive (or the pid is reused by a live
+  process), it refuses with `refused: ... being written by another command; try again` (exit 3). Nothing
+  is written.
+- A lock whose pid is gone (`kill(pid, 0)` returns ESRCH) also refuses, and nothing reclaims it. The
+  refusal names the path and the pid. A human checks that no write is running and removes the file. This
+  is the crash case: the holder died mid-write, and a human clears it.
+- An empty lock, or one that is not a pid, refuses. Its holder may still be between create and write. A
+  holder that died in that gap leaves an empty lock; a human removes it.
+
+Reclaim was removed at Sage's ruling (sage-1429, 10-20). It was the one design with a race, so the
+race below is gone, not accepted.
+
+Former limit, now removed: reclaim race. The old design let a writer take a stale lock by unlinking it
+and retaking it. The case that lost: writers A and B both read the same dead pid N. A unlinks the lock
+and takes it. B then unlinks A's live lock and takes its own. Both read the same revision, both write
+it, and the second rename silently replaces the first. The revision check did not catch it, because both
+had read the old revision before either wrote.
+
+Known limits, stated plainly:
+1. A dead holder's lock blocks every write until a human removes it. That is the fail-closed price of
+   no reclaim. The refusal says which pid and which path.
+2. A reused pid reads as alive, so a stale lock refuses. The fix is to remove the file by hand.
+3. The lock is per access file. It does not cover the bus's own reads.
+4. Crash-safety of the write path: the temp file is removed on any failure before or at the rename. The
+   directory is not fsynced after the rename, so a power loss right after a rename can lose the rename.
+   The bytes are never mixed.
+
+Tests for the lock (all in `access.test.mjs`):
+- "a live holder's lock refuses and leaves the file and the lock alone": pid = this process.
+- "an empty or unreadable lock refuses": empty file, and `not-a-pid`.
+- "a lock left by a dead pid refuses, names the pid, and is not reclaimed": a child that has exited. The
+  file, the lock and the receipt are unchanged.
+- "the lock is mode 0600 while held and removed after a refused write".
+
+Tests for the write path and the refusals (added in this round):
+- "a failed rename leaves the old bytes, removes the temp file, and writes no receipt": the fs seam
+  (`deps.fs`) makes `renameSync` throw. Checks the old bytes, no `.access-*.tmp`, no lock, no receipt.
+- "a group-writable access file refuses with exit 3, names the file, and changes nothing": a 0664 file.
+  Exit 3, the file path in the message, nothing written.
+- "an agent or tester caller is refused before the context or the access file is read": `contextFor`
+  throws if called, and the file is 0664. The refusal must come first.
+
+## The human proof, and the bus behavior behind test 10
+
+The proof is one `project.list` call through `humanTransport`. The bus gates it with `#human`
+(`packages/bus/src/broker.mjs`, the `project.list` case at :2319, and `#human` at :377). The call is in
+one function, `proveHuman` in `access.mjs`, for R4 to swap.
+
+Test 10 runs the real `human-cli.mjs` on a scratch bus from agent ancestry (`CLAUDECODE=1` in the child's
+env). The bus refuses. The client reports `outcome-unknown`, not `human-required`, because the bus closes
+the socket on a failed proof and `packages/bus/src/client.mjs:32-33` maps a closed socket to
+`outcome-unknown`. Exit 1 (`busExit`). The test pins that code and asserts the access file and the
+receipt are unchanged.
+
+This is a bus behavior outside R5. It is not changed here. Gizmoduck and Gander own the verifier (row 196).
+Until it changes, a human who hits the agent refusal sees `outcome-unknown`.
+
+## Context
+
+`accessContextFor(system, env)`:
+- `providers`: `system.console.sso.providers[].id`. Row 192's shape (packages/webui/src/sso-config.mjs on
+  row 192's candidate).
+- `ssoSubjects`: each provider's `subjects[].sub`, paired with the provider id. Gizmoduck's design says
+  `console.sso.subjects`; Sage ruled that is shorthand for this (erratum).
+- `peers`: `[]` until row 203 adds the federation key. A grant that names a peer home refuses.
+- `businesses`: `loadBusiness` for each `<configDir>/businesses/*.json`; `human` and the role names as
+  `instances`. A business file that fails to load fails the command.
+
+No `console` key gives empty providers and subjects, so every grant naming a subject refuses. The
+`checkConsole` check from row 192 is not on this branch yet. R5 rebases onto row 192's landing, and then
+reads `console` through `checkConsole`.
+
+## Mutant list (one per refusal; run on Sage's go, before review)
+
+| # | Mutant | Expected kill |
+|---|---|---|
+| M1 | remove the `refuseInsideAgent` call | "an agent caller is refused before the bus is asked" |
+| M2 | remove the `--tester` check | "--tester is refused on every verb" |
+| M3 | the proof's error is swallowed | "a bus that refuses the human proof blocks the write" |
+| M4 | the revision compare is removed | "a stale revision refuses with revision-conflict" |
+| M5 | `takeLock` unlinks a dead-pid lock and retakes it (the reclaim this round removed) | "a lock left by a dead pid refuses, names the pid, and is not reclaimed" |
+| M6 | `pidAlive` always returns true (a dead pid reads as live) | "a lock left by a dead pid refuses, names the pid, and is not reclaimed" |
+| M11 | `writeAtomic` writes straight to access.json, no temp file or rename | "a failed rename leaves the old bytes, removes the temp file, and writes no receipt" |
+| M12 | the BusinessError catch in `accessCommand` is removed | "a group-writable access file refuses with exit 3, names the file, and changes nothing" |
+| M13 | `contextFor()` is called before the agent and tester refusals | "an agent or tester caller is refused before the context or the access file is read" |
+| M7 | `checkAccess` is skipped before the write | "a grant naming an unknown instance is refused before any write" |
+| M8 | the receipt append is removed | "grant writes ... a receipt line" |
+| M9 | a project name is written as given (no lookup) | "a project name resolves to its id" |
+| M10 | the lock is not taken | "a live holder's lock refuses" |
+
+Round 2 closed the direct-write gap: `writeAtomic` takes the fs calls through `deps.fs` (default: the real
+`node:fs` functions), and a rename that throws is tested (M11 is the direct-write mutant). Not yet run:
+the mutant batch, the cli suite and `scripts/test-*.sh`. All wait on Sage's slot.
+
+Round 2 also changed the file's refusal path: a `BusinessError` from `loadAccess` or `loadBusiness` now
+exits 3 with the file path and key path on stderr, no stack trace (Duckworth B1, Sage sage-1437).
+
+## Not done in this row
+
+- `--peers` and the federation key: row 203.
+- `access.reload`: row R4.
+- Gizmoduck's `console.sso.subjects` name: erratum, the flattened shape is used.
+- The suite (`packages/cli` and every `scripts/test-*.sh`) and the mutant batch: on Sage's gate.

agents/quackerjack/work/queue-202/CANDIDATE.sha256

@@ -0,0 +1,6 @@
+e2d3e613a8d6f04544904acb2af8aec44dedf9ba6820f1936e1f7d6547be2028  packages/cli/src/access.mjs
+e956ac5b54844af30ac7717e85b5b60282b2ccf00dfc134d1d5c1d9f3cb44f32  packages/cli/src/cli.mjs
+de7d15dc6989379a47b1efd4f449e9707004978198f01d704b2d61c8411ed6ca  packages/cli/tests/access.test.mjs
+f50760a67337147e50af032969ea65ca313ac7b76f6239e23e5c0d95431bd4b7  packages/cli/README.md
+aeddef32c28c883eedf166bcac96d1e6828b71c862e683977e097706339baf86  scripts/mosaic
+79f2c5344c0d73754804ab58c68edfb82bad7bfef50718550c698f61ae2a8ab5  agents/quackerjack/work/queue-202/BUILD.md

agents/quackerjack/work/queue-202/MANIFEST.md

@@ -0,0 +1,64 @@
+# Row 202 manifest: FED R5, mosaic access list, grant, revoke (round 2)
+
+Candidate: 48a3fb96e on quackerjack/fed-r5 (round 2). Supersedes the round-1 manifest at 959bfb275, which
+pointed at build 030809e15 and was reviewed by Duckworth as round 1 (changes, B1; REVIEW-r1.md, a76767e87).
+Base: R1 at 80fe31071, merged; 44e36fc4c and 35aaceac9 on the branch before the build.
+Owner Quackerjack, reviewer Duckworth, gate owner Sage. Brief: docs/plans/2026-10-20_federation-r1-r2-r5.md, Brief: FED R5.
+
+## Files (sha256 of the blob at 48a3fb96e)
+
+```
+e2d3e613a8d6f04544904acb2af8aec44dedf9ba6820f1936e1f7d6547be2028  packages/cli/src/access.mjs
+e956ac5b54844af30ac7717e85b5b60282b2ccf00dfc134d1d5c1d9f3cb44f32  packages/cli/src/cli.mjs
+de7d15dc6989379a47b1efd4f449e9707004978198f01d704b2d61c8411ed6ca  packages/cli/tests/access.test.mjs
+f50760a67337147e50af032969ea65ca313ac7b76f6239e23e5c0d95431bd4b7  packages/cli/README.md
+aeddef32c28c883eedf166bcac96d1e6828b71c862e683977e097706339baf86  scripts/mosaic
+79f2c5344c0d73754804ab58c68edfb82bad7bfef50718550c698f61ae2a8ab5  agents/quackerjack/work/queue-202/BUILD.md
+```
+
+scripts/mosaic is unchanged since round 1.
+
+## What changed in round 2
+
+- Lock: no reclaim. A dead-pid, empty or unreadable lock refuses and names the path (and pid); a human
+  removes it. The reclaim race is gone (Sage sage-1429).
+- Atomic write: fs calls go through `deps.fs` (default: the real `node:fs` functions). A failed write
+  removes its temp file and leaves the old bytes (Sage sage-1429, the direct-write gap).
+- BusinessError from loadAccess or loadBusiness: exit 3, file and key path on stderr, no stack trace
+  (Duckworth B1, Sage sage-1437). Sage's ruling is exit 3, so the checkAccess refusals move from exit 2 to
+  exit 3 too.
+- `contextFor` is a function, built after the agent and tester refusals and the human proof. A refused
+  caller never reads access.json or the business files (Sage sage-1437).
+- The help text and README say the command runs as the instance's uid (Duckworth N6, Sage sage-1437).
+
+## Interface used from R1 (80fe31071)
+
+checkAccess(doc, { providers, peers, businesses, ssoSubjects }), loadBusiness, loadAccess (via readCurrent),
+accessFilePath is not used (the CLI takes configDir), covers is not used by R5.
+
+## Named in review
+
+- Human proof: one project.list call (proveHuman, access.mjs). Gate: packages/bus/src/broker.mjs:2319
+  (project.list case) and :377 (#human). Agent and --tester refusals come before the proof.
+- Lock: <configDir>/access.json.lock, 0600, pid stamp. Live pid refuses (BUSY); dead, empty or unreadable
+  refuses and names the path. No reclaim. See BUILD.md.
+- Write: checkAccess on the new document, then temp file, fsync, rename; revision compared inside the lock.
+- Pinned bus behavior: a failed proof reads as outcome-unknown (client.mjs:32-33). Outside R5.
+- Context: accessContextFor, built lazily; peers [] until row 203; subjects flattened from
+  console.sso.providers[].subjects.
+
+## Tests and mutants
+
+- packages/cli/tests/access.test.mjs: 21 tests, single file green on 48a3fb96e (21/21, run on the candidate).
+- Mutants M1-M13 in BUILD.md. M11 (direct write) and M12 (no BusinessError catch) and M13 (context built
+  early) are new. Run on Sage's go and slot only.
+- Not run in this round: the mutant batch, the cli suite and scripts/test-*.sh.
+
+## Not in this row
+
+- R2 peers and the federation key (row 203).
+- R4 access.reload (its brief takes N1: project.list exempts testers, so access.reload needs #human).
+- row 192 checkConsole (the context reads console.sso directly until 192 lands).
+- Viewer level (Sage's carry, item 5): whichever of 202 and 204 lands second adds it. Row 204 is not on
+  refactor yet as of 10-20 20:23Z.
+- Cli suite and scripts/test-*.sh (Sage's gate).

agents/quackerjack/work/queue-202/PLAN.md

@@ -0,0 +1,106 @@
+# Row 202, FED R5: `mosaic access list`, `grant`, `revoke`
+
+Quackerjack, 2026-10-20. Brief: `docs/plans/2026-10-20_federation-r1-r2-r5.md`, "Brief: FED R5". Design:
+`agents/gizmoduck/work/federation/DESIGN.md` at a1daa3c07 (sections 3.5, 3.7, 7 row R5). Reviewer Duckworth.
+Chained on row 201 (R1, Gizmoduck). Interface as Sage relayed it (sage-1400, gizmoduck-0030).
+
+## Status before build
+
+- Claim: `scripts/mosaic queue move 202 in-progress --op quackerjack-202-start --by quackerjack`, run from
+  the canonical checkout, exits 2: "row 202 waits on 201 (done; now briefed)". Row 201 is `briefed`, so the
+  claim is not made. I will not build past the plan until Sage says how to proceed. This plan is a file in
+  my own worktree; it changes no queue row.
+- `gizmoduck/fed-r1` is not on origin yet. R5 imports `packages/business/src/access.mjs` only after R1 lands.
+  Until then, code and tests run against the names in sage-1400, with the R1 import stubbed in one place.
+
+## Interface I build against (R1, as relayed)
+
+- `checkAccess(doc, { providers, peers, businesses, ssoSubjects })`: pure. Returns the checked document,
+  frozen. Throws `BusinessError` (exit 2) naming the key path. `ssoSubjects` is required; a missing one fails
+  closed.
+- `covers(grant, { business, project, instance }, now, { level } = {})`.
+- `accessFilePath(dir = configDir())`: `<configDir>/access.json`.
+- `loadAccess(file, context)`: one read, refuses a symlink, a non-regular file, another owner, or group or
+  other write, then runs `checkAccess`. An expired grant is not refused here.
+
+## Files I will change
+
+New:
+- `packages/cli/src/access.mjs`: argument parsing for `list`, `grant`, `revoke`; the human check; the write;
+  the receipt; the usage text. Exports a `main`-style function the way `thread.mjs` and `project.mjs` do.
+- `packages/cli/tests/access.test.mjs`: all R5 tests below.
+
+Edited:
+- `scripts/mosaic`: add `access` to the dispatch case that sends a verb to `packages/cli/src/cli.mjs`.
+- `packages/cli/src/cli.mjs`: route `access` to `access.mjs`.
+- `packages/cli/README.md`: the three verbs, the `instances` limit, and the provider-removal order.
+
+Not touched: `packages/business/src/access.mjs` (R1 owns it), `scripts/mosaic-config.mjs` (R2), any bus
+broker code (R3/R4), `~/.mosaic-dev`, `~/.config/mosaic-dev`, the units, any live `access.json`.
+
+## Behaviour
+
+- `list`: prints the users, grants and revision of `accessFilePath()`. Reads through `loadAccess`, so a bad
+  file refuses here too. Shows each grant's project as the id (and the name, when `project.list` resolves
+  it). Shows `["*"]` as "all projects, now and later".
+- `grant`: `--user`, `--business`, `--projects`, `--instances`, `--level collaborator`, optional
+  `--expires`, `--revision N`. Builds the new document in memory, runs `checkAccess` on it, then writes. A
+  bad grant refuses before any write. `--project <name>` resolves the name through `project.list` at grant
+  time and writes the id (design 3.5).
+- `revoke`: removes the user's grants, or one grant with `--grant ID`, same flow.
+- Write: a temp file in the same directory, mode 0600, fsync, rename over `access.json`. Revision goes up by
+  one. The caller passes the revision it read, and a mismatch refuses with `revision-conflict` before the
+  rename.
+- Receipt: one line appended to `<dataRoot>/state/access-log.jsonl`. Append-only, same shape as
+  `activation-log.jsonl` (`packages/runs/src/state.mjs`). It records the time, the verb, the actor, the
+  revision before and after, and the grant ids touched. No secret or token goes in it.
+- Help text states two things. First, a grant's `instances` is the real limit: a collaborator drives the
+  granted instance with the owner's role (design 3.5). Second, the removal order: take a user out of
+  `access.json` first, which acts at once. Removing a provider from `console.sso` takes effect only after a
+  Console restart (design 3.7).
+
+## Human proof
+
+The check runs as the human transport does now: `humanTransport` (`packages/cli/src/transport.mjs`) runs
+`packages/bus/src/human-cli.mjs` against the bus socket, and `refuseInsideAgent` refuses first in any agent
+ancestry. Open point, for Sage or Gizmoduck to settle before build: the design names no bus verb for the
+grant check. My reading is that R5 makes one call through `humanTransport` to a read the bus already gates
+as human-only, and uses its success as the proof, with no new bus verb (R5 must not widen the bus).
+If that is wrong, I stop and report it.
+
+Tests use two stand-ins, the pattern `packages/cli/tests/helpers.mjs` already has:
+- Stand-in human CLI: `fakeCli(root, body)` replaces `human-cli.mjs` as the `cli` argument of
+  `humanTransport`, so the answer comes from a table. Used for the caller-refusal tests and most of the rest.
+- Scratch bus: `startBroker` from `packages/bus/src/runtime.mjs` on a scratch socket and scratch data root.
+  One integration test runs the real `HUMAN_CLI` against it, so the proof path is checked end to end. The
+  bus accepts only its own `human-cli.mjs` path (memory #225), so that test uses the real file, not a copy.
+- Tester caller: a `tester` proof, through `testerTransport` with `TESTER_CLI`. Refused with `tester-refused`
+  or `tester-required` as the bus returns it.
+- Agent caller: env with `MOSAIC_RUN_ID` (and the other markers in `AGENT_MARKERS`) set. Refused by
+  `refuseInsideAgent` (exit 3) before any transport call.
+
+## Test list (`packages/cli/tests/access.test.mjs`) and one mutant per refusal
+
+Each test uses a scratch `MOSAIC_CONFIG` dir and a scratch data root. None reads `~/.config/mosaic-dev`.
+
+| # | Refusal or behaviour | Test | Mutant (must be killed) |
+|---|---|---|---|
+| 1 | Agent caller refused | env with `MOSAIC_RUN_ID` runs `grant`; exit 3, no file change | `refuseInsideAgent` call removed from the access path |
+| 2 | Tester caller refused | `tester` proof runs `grant`; `tester-refused` (exit 3), no write | tester branch lets a tester write |
+| 3 | Human proof required | stand-in answers `human-required`; exit 3, no write | proof result ignored |
+| 4 | Concurrent write refused | two writers read revision 3; second with `--revision 3` gets `revision-conflict`; file keeps revision 4 | revision compare removed |
+| 5 | Receipt appended | after `grant`, one new line in `access-log.jsonl` with both revisions; a second write adds a second line, the first is unchanged | receipt write removed, or the write truncates the log |
+| 6 | Bad grant refused before write | grant with a non-UUID project, unknown instance, level `viewer`; exit 2, file bytes unchanged | `checkAccess` runs after the rename |
+| 7 | Atomic write | the write is a temp file and a rename; a failed rename leaves the old file whole | direct write to `access.json` |
+| 8 | Revoke removes the grant | `revoke` removes the user; `list` no longer shows it; revision +1 | revoke leaves the grant |
+| 9 | `--project <name>` resolves to an id | name resolves through `project.list`; the file holds the id | name written as-is |
+| 10 | Real proof path | scratch `startBroker` plus real `HUMAN_CLI` with a valid proof; grant succeeds | (control: the success path must pass with no mutant) |
+
+The mutant batch needs Sage's slot. Single test files run freely.
+
+## Gate
+
+- Duckworth approves this manifest and the code.
+- The cli suite and every `scripts/test-*.sh` green on Sage's gate.
+- Each mutant above is killed.
+- Rebase onto R1's landing; re-run every touched test file singly before in-review.

docs/SESSIONS.md

@@ -1363,3 +1363,4 @@ 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)
+2026-10-20T19:57:00Z | Gizmoduck (Opus 5.5, 9312a896) | row 201 FED R1 (#1699, #414) round 1: packages/business/src/access.mjs, index export, tests/access.test.mjs, packet agents/gizmoduck/work/queue-201 | 24/24 single file; 44 mutants written, not run (needs Sage's slot); expiry per sage-1399; to Duckworth for manifest review

packages/business/src/access.mjs

@@ -0,0 +1,185 @@
+// The access file, <configDir>/access.json (federation design section 3.5,
+// FED R1, #414). It names the extra users who may sign in to this instance
+// and the grants that let them reach a business's threads. The validator is
+// pure: providers, peers, businesses and the owner's sign-in subjects come in
+// as arguments. Any failed rule refuses the whole file, which leaves every
+// user with no grant (fail closed).
+
+import { join } from "node:path";
+import { refuse } from "./errors.mjs";
+import { configDir } from "./business.mjs";
+import { isPlainObject, requireObject, rejectUnknownKeys, requireId, requirePositiveInt, readJsonFile, deepFreeze } from "./util.mjs";
+
+// The grant levels. Row 193a widens this to collaborator and viewer.
+export const LEVELS = Object.freeze(["collaborator"]);
+// Ids a user may never take: the bus's own principals.
+const RESERVED_USERS = Object.freeze(["human", "tester"]);
+const LOCAL_HOME = "local";
+const ALL = "*";
+const UUID = /^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$/;
+const ISO_TIME = /^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}(\.\d{1,3})?Z$/;
+const SUB_MAX = 255;
+
+export function accessFilePath(dir = configDir()) {
+  return join(dir, "access.json");
+}
+
+function requireArray(value, where) {
+  if (!Array.isArray(value)) refuse(`${where} must be an array`);
+  return value;
+}
+
+function requireText(value, where) {
+  if (typeof value !== "string" || value.length === 0 || value.length > SUB_MAX || value.includes("\0")) {
+    refuse(`${where} must be a non-empty string of at most ${SUB_MAX} characters`);
+  }
+  return value;
+}
+
+function subjectKey(provider, sub) {
+  return JSON.stringify([provider, sub]);
+}
+
+function checkContext(context) {
+  const where = "access context";
+  requireObject(context, where);
+  rejectUnknownKeys(context, ["providers", "peers", "businesses", "ssoSubjects"], where);
+  const providers = new Set(requireArray(context.providers, `${where}.providers`).map((p, i) => requireText(p, `${where}.providers[${i}]`)));
+  const peers = new Set(requireArray(context.peers, `${where}.peers`).map((p, i) => requireId(p, `${where}.peers[${i}]`)));
+  if (peers.has(LOCAL_HOME)) refuse(`${where}.peers must not name ${JSON.stringify(LOCAL_HOME)}`);
+  requireObject(context.businesses, `${where}.businesses`);
+  const businesses = new Map();
+  for (const [id, business] of Object.entries(context.businesses)) {
+    const at = `${where}.businesses.${id}`;
+    requireId(id, `${where}.businesses key`);
+    requireObject(business, at);
+    requireId(business.human, `${at}.human`);
+    const instances = requireArray(business.instances, `${at}.instances`).map((x, i) => requireId(x, `${at}.instances[${i}]`));
+    businesses.set(id, { human: business.human, instances: new Set(instances) });
+  }
+  const owners = new Set();
+  requireArray(context.ssoSubjects, `${where}.ssoSubjects`).forEach((s, i) => {
+    const at = `${where}.ssoSubjects[${i}]`;
+    requireObject(s, at);
+    owners.add(subjectKey(requireText(s.provider, `${at}.provider`), requireText(s.sub, `${at}.sub`)));
+  });
+  return { providers, peers, businesses, owners };
+}
+
+function checkUser(user, at, ctx, humans, seenSubjects) {
+  requireObject(user, at);
+  rejectUnknownKeys(user, ["id", "home", "subjects"], at);
+  requireId(user.id, `${at}.id`);
+  if (RESERVED_USERS.includes(user.id)) refuse(`${at}.id must not be ${JSON.stringify(user.id)}, a bus principal`);
+  if (humans.has(user.id)) refuse(`${at}.id must not be a business's human (${JSON.stringify(user.id)})`);
+  if (user.home !== LOCAL_HOME && !ctx.peers.has(user.home)) {
+    refuse(`${at}.home must be a configured peer or ${JSON.stringify(LOCAL_HOME)} (got ${JSON.stringify(user.home)})`);
+  }
+  const subjects = requireArray(user.subjects, `${at}.subjects`);
+  if (subjects.length === 0) refuse(`${at}.subjects must not be empty`);
+  subjects.forEach((s, i) => {
+    const sat = `${at}.subjects[${i}]`;
+    requireObject(s, sat);
+    rejectUnknownKeys(s, ["provider", "sub"], sat);
+    if (typeof s.provider !== "string" || !ctx.providers.has(s.provider)) {
+      refuse(`${sat}.provider must be a configured provider (got ${JSON.stringify(s.provider)})`);
+    }
+    requireText(s.sub, `${sat}.sub`);
+    const key = subjectKey(s.provider, s.sub);
+    if (ctx.owners.has(key)) refuse(`${sat} is an owner sign-in subject (console.sso.subjects)`);
+    if (seenSubjects.has(key)) refuse(`${sat} appears more than once in the file`);
+    seenSubjects.add(key);
+  });
+}
+
+// Either ["*"] alone or a non-empty list of distinct entries, each checked.
+function checkScope(value, where, check) {
+  const list = requireArray(value, where);
+  if (list.length === 0) refuse(`${where} must not be empty`);
+  if (list.includes(ALL)) {
+    if (list.length !== 1) refuse(`${where} must be ["*"] alone or list entries without "*"`);
+    return;
+  }
+  const seen = new Set();
+  list.forEach((entry, i) => {
+    check(entry, `${where}[${i}]`);
+    if (seen.has(entry)) refuse(`duplicate entry in ${where}: ${JSON.stringify(entry)}`);
+    seen.add(entry);
+  });
+}
+
+function checkExpires(value, where) {
+  if (typeof value !== "string" || !ISO_TIME.test(value) || Number.isNaN(Date.parse(value))) {
+    refuse(`${where} must be an ISO time such as 2026-12-31T00:00:00Z (got ${JSON.stringify(value)})`);
+  }
+  const iso = new Date(value).toISOString();
+  if (iso.slice(0, 19) !== value.slice(0, 19)) refuse(`${where} is not a real time: ${value}`);
+}
+
+function checkGrant(grant, at, ctx, users, seenGrants) {
+  requireObject(grant, at);
+  rejectUnknownKeys(grant, ["id", "user", "business", "projects", "instances", "level", "expires"], at);
+  requireId(grant.id, `${at}.id`);
+  if (seenGrants.has(grant.id)) refuse(`${at}.id is a duplicate grant id: ${grant.id}`);
+  seenGrants.add(grant.id);
+  if (typeof grant.user !== "string" || !users.has(grant.user)) refuse(`${at}.user must name a user in this file (got ${JSON.stringify(grant.user)})`);
+  if (typeof grant.business !== "string" || !ctx.businesses.has(grant.business)) {
+    refuse(`${at}.business must name a declared business (got ${JSON.stringify(grant.business)})`);
+  }
+  const business = ctx.businesses.get(grant.business);
+  checkScope(grant.projects, `${at}.projects`, (p, where) => {
+    if (typeof p !== "string" || !UUID.test(p)) refuse(`${where} must be "*" or a bus project id, a lowercase UUID (got ${JSON.stringify(p)})`);
+  });
+  checkScope(grant.instances, `${at}.instances`, (x, where) => {
+    if (typeof x !== "string" || !business.instances.has(x)) refuse(`${where} must be "*" or a declared instance of ${grant.business} (got ${JSON.stringify(x)})`);
+  });
+  if (!LEVELS.includes(grant.level)) refuse(`${at}.level must be one of ${LEVELS.join(", ")} (got ${JSON.stringify(grant.level)})`);
+  if (grant.expires !== undefined) checkExpires(grant.expires, `${at}.expires`);
+}
+
+// Check a parsed access document against the instance's context. Returns the
+// document frozen. Every refusal is a BusinessError naming the key path. An
+// expired grant is not refused: covers() treats it as absent.
+export function checkAccess(document, context) {
+  const ctx = checkContext(context);
+  const humans = new Set([...ctx.businesses.values()].map((b) => b.human));
+  if (!isPlainObject(document)) refuse("access file must be a JSON object");
+  rejectUnknownKeys(document, ["accessVersion", "revision", "users", "grants"], "access file");
+  if (document.accessVersion !== 1) refuse(`accessVersion must be 1 (got ${JSON.stringify(document.accessVersion)})`);
+  requirePositiveInt(document.revision, "revision");
+  const users = new Set();
+  const seenSubjects = new Set();
+  requireArray(document.users, "users").forEach((user, i) => {
+    checkUser(user, `users[${i}]`, ctx, humans, seenSubjects);
+    if (users.has(user.id)) refuse(`users[${i}].id is a duplicate user id: ${user.id}`);
+    users.add(user.id);
+  });
+  const seenGrants = new Set();
+  requireArray(document.grants, "grants").forEach((grant, i) => checkGrant(grant, `grants[${i}]`, ctx, users, seenGrants));
+  return deepFreeze(structuredClone(document));
+}
+
+// Read and check the access file. One descriptor, opened without following a
+// link, serves the stat checks and the read (readJsonFile). The file holds
+// authority, so it must belong to this uid and not be writable by group or
+// other, as the business file is.
+export function loadAccess(file, context, { uid = process.getuid() } = {}) {
+  const document = readJsonFile(file, "access file", (stat) => {
+    if (stat.uid !== uid) refuse(`access file must belong to uid ${uid}: ${file}`);
+    if ((stat.mode & 0o022) !== 0) refuse(`access file must not be writable by group or other (mode ${(stat.mode & 0o777).toString(8)}): ${file}`);
+  });
+  return checkAccess(document, context);
+}
+
+// Does a checked grant cover a thread? `target` is the thread's business, bus
+// project id and instance. With `level`, the grant's level must be that one;
+// without it, any level covers. An expired grant covers nothing.
+export function covers(grant, { business, project, instance }, now, { level } = {}) {
+  if (!(now instanceof Date) || Number.isNaN(now.getTime())) throw new TypeError("covers needs a valid Date for now");
+  if (grant.expires !== undefined && now.getTime() >= Date.parse(grant.expires)) return false;
+  if (grant.business !== business) return false;
+  if (!(grant.projects[0] === ALL || grant.projects.includes(project))) return false;
+  if (!(grant.instances[0] === ALL || grant.instances.includes(instance))) return false;
+  if (level !== undefined && grant.level !== level) return false;
+  return true;
+}

packages/business/src/index.mjs

@@ -10,5 +10,6 @@ export { validateRoleDocument, loadRoleFile, loadRole } from "./role.mjs";
 export { LAYERS, REGISTRY, THINKING, FALLBACK_VARS, checkVars, mergeVars } from "./vars.mjs";
 export { parseCredentialRef, checkCredentialRef } from "./credentials.mjs";
 export { configDir, businessFilePath, validateBusinessDocument, loadBusiness } from "./business.mjs";
+export { LEVELS, accessFilePath, checkAccess, loadAccess, covers } from "./access.mjs";
 export { projectFilePath, validateProjectDocument, loadProject } from "./project.mjs";
 export { systemVars, resolveInstance, classify } from "./resolve.mjs";

packages/business/tests/access.test.mjs

@@ -0,0 +1,280 @@
+// FED R1 (#414, row 201): the access file loader and validator, DESIGN.md
+// section 3.5, and covers(). Every test works in a scratch directory.
+
+import { test } from "node:test";
+import assert from "node:assert/strict";
+import { chmodSync, mkdirSync, symlinkSync } from "node:fs";
+import { join } from "node:path";
+import { BusinessError } from "../src/errors.mjs";
+import { LEVELS, accessFilePath, checkAccess, loadAccess, covers } from "../src/access.mjs";
+import { tmp, writeJson } from "./helpers.mjs";
+
+const P1 = "0f8b6c1e-2a3d-4e5f-8a9b-0c1d2e3f4a5b";
+const P2 = "11111111-2222-4333-8444-555555555555";
+
+function context(over = {}) {
+  return {
+    providers: ["authentik"],
+    peers: ["factory"],
+    businesses: {
+      "creative-hub": { human: "melanie", instances: ["researcher", "writer"] },
+      acme: { human: "jason", instances: ["coder"] },
+    },
+    ssoSubjects: [{ provider: "authentik", sub: "owner-sub" }],
+    ...over,
+  };
+}
+
+function doc() {
+  return {
+    accessVersion: 1,
+    revision: 3,
+    users: [
+      { id: "bean", home: "factory", subjects: [{ provider: "authentik", sub: "s-1" }] },
+      { id: "chet", home: "local", subjects: [{ provider: "authentik", sub: "s-2" }] },
+    ],
+    grants: [
+      { id: "g-1", user: "bean", business: "creative-hub", projects: ["*"], instances: ["researcher"], level: "collaborator", expires: "2026-12-31T00:00:00Z" },
+      { id: "g-2", user: "chet", business: "creative-hub", projects: [P1], instances: ["*"], level: "collaborator" },
+    ],
+  };
+}
+
+// Refuses with a BusinessError, exit 2 unless given, and a message matching `pattern`.
+function refuses(fn, pattern, exitCode = 2) {
+  assert.throws(fn, (error) => {
+    assert.ok(error instanceof BusinessError, `not a BusinessError: ${error}`);
+    assert.equal(error.exitCode, exitCode);
+    assert.match(error.message, pattern);
+    return true;
+  });
+}
+
+function mutated(change) {
+  const d = doc();
+  change(d);
+  return d;
+}
+
+test("a valid document passes and comes back frozen", () => {
+  const checked = checkAccess(doc(), context());
+  assert.deepEqual(checked, doc());
+  assert.ok(Object.isFrozen(checked));
+  assert.ok(Object.isFrozen(checked.grants[0].projects));
+});
+
+test("checkAccess does not freeze or alias the caller's document", () => {
+  const d = doc();
+  const checked = checkAccess(d, context());
+  assert.ok(!Object.isFrozen(d));
+  assert.notEqual(checked.grants, d.grants);
+});
+
+test("LEVELS is the single allowed level set, collaborator only", () => {
+  assert.deepEqual([...LEVELS], ["collaborator"]);
+  assert.ok(Object.isFrozen(LEVELS));
+});
+
+test("accessFilePath is access.json in the config directory", () => {
+  assert.equal(accessFilePath("/x/y"), join("/x/y", "access.json"));
+  const dir = tmp();
+  const saved = process.env.MOSAIC_CONFIG;
+  process.env.MOSAIC_CONFIG = join(dir, "config.json");
+  try {
+    assert.equal(accessFilePath(), join(dir, "access.json"));
+  } finally {
+    if (saved === undefined) delete process.env.MOSAIC_CONFIG;
+    else process.env.MOSAIC_CONFIG = saved;
+  }
+});
+
+test("top level: object, unknown keys, accessVersion, revision, arrays", () => {
+  refuses(() => checkAccess([], context()), /access file must be a JSON object/);
+  refuses(() => checkAccess(mutated((d) => { d.extra = 1; }), context()), /unsupported access file key: "extra"/);
+  refuses(() => checkAccess(mutated((d) => { d.accessVersion = 2; }), context()), /accessVersion must be 1/);
+  refuses(() => checkAccess(mutated((d) => { delete d.accessVersion; }), context()), /accessVersion must be 1/);
+  for (const bad of [0, -1, 1.5, "3", undefined]) {
+    refuses(() => checkAccess(mutated((d) => { d.revision = bad; }), context()), /revision must be a positive integer/);
+  }
+  refuses(() => checkAccess(mutated((d) => { d.users = {}; }), context()), /^users must be an array/);
+  refuses(() => checkAccess(mutated((d) => { delete d.grants; }), context()), /^grants must be an array/);
+});
+
+test("users: unknown keys and the id rule", () => {
+  refuses(() => checkAccess(mutated((d) => { d.users[1].role = "x"; }), context()), /unsupported users\[1\] key: "role"/);
+  refuses(() => checkAccess(mutated((d) => { d.users[0] = "bean"; }), context()), /users\[0\] must be a JSON object/);
+  refuses(() => checkAccess(mutated((d) => { d.users[0].id = "Bean"; }), context()), /users\[0\]\.id must match/);
+  refuses(() => checkAccess(mutated((d) => { d.users[1].id = "bean"; }), context()), /users\[1\]\.id is a duplicate user id: bean/);
+});
+
+test("users: human, tester and any business's human are refused", () => {
+  refuses(() => checkAccess(mutated((d) => { d.users[0].id = "human"; d.grants = []; }), context()), /users\[0\]\.id must not be "human"/);
+  refuses(() => checkAccess(mutated((d) => { d.users[1].id = "tester"; d.grants = []; }), context()), /users\[1\]\.id must not be "tester"/);
+  refuses(() => checkAccess(mutated((d) => { d.users[0].id = "melanie"; d.grants = []; }), context()), /users\[0\]\.id must not be a business's human \("melanie"\)/);
+  // The human of a business the grant doesn't name is refused too.
+  refuses(() => checkAccess(mutated((d) => { d.users[1].id = "jason"; d.grants = []; }), context()), /users\[1\]\.id must not be a business's human \("jason"\)/);
+});
+
+test("users: home is a given peer or local", () => {
+  refuses(() => checkAccess(mutated((d) => { d.users[0].home = "elsewhere"; }), context()), /users\[0\]\.home must be a configured peer or "local" \(got "elsewhere"\)/);
+  refuses(() => checkAccess(mutated((d) => { delete d.users[1].home; }), context()), /users\[1\]\.home must be a configured peer/);
+  refuses(() => checkAccess(doc(), context({ peers: [] })), /users\[0\]\.home must be a configured peer/);
+});
+
+test("users: subjects, provider, sub, uniqueness and owner subjects", () => {
+  refuses(() => checkAccess(mutated((d) => { d.users[0].subjects = []; }), context()), /users\[0\]\.subjects must not be empty/);
+  refuses(() => checkAccess(mutated((d) => { delete d.users[0].subjects; }), context()), /users\[0\]\.subjects must be an array/);
+  refuses(() => checkAccess(mutated((d) => { d.users[0].subjects[0].extra = 1; }), context()), /unsupported users\[0\]\.subjects\[0\] key: "extra"/);
+  refuses(() => checkAccess(mutated((d) => { d.users[1].subjects[0].provider = "google"; }), context()), /users\[1\]\.subjects\[0\]\.provider must be a configured provider \(got "google"\)/);
+  refuses(() => checkAccess(mutated((d) => { d.users[0].subjects[0].sub = ""; }), context()), /users\[0\]\.subjects\[0\]\.sub must be a non-empty string/);
+  refuses(() => checkAccess(mutated((d) => { d.users[0].subjects[0].sub = 7; }), context()), /users\[0\]\.subjects\[0\]\.sub must be a non-empty string/);
+  // A pair twice in one user, and across two users.
+  refuses(() => checkAccess(mutated((d) => { d.users[0].subjects.push({ provider: "authentik", sub: "s-1" }); }), context()), /users\[0\]\.subjects\[1\] appears more than once/);
+  refuses(() => checkAccess(mutated((d) => { d.users[1].subjects[0].sub = "s-1"; }), context()), /users\[1\]\.subjects\[0\] appears more than once/);
+  // The owner's own sign-in subject can't be an extra user.
+  refuses(() => checkAccess(mutated((d) => { d.users[1].subjects[0].sub = "owner-sub"; }), context()), /users\[1\]\.subjects\[0\] is an owner sign-in subject/);
+  // The same sub under another provider is a different pair.
+  const twoProviders = context({ providers: ["authentik", "google"] });
+  assert.ok(checkAccess(mutated((d) => { d.users[1].subjects[0] = { provider: "google", sub: "owner-sub" }; }), twoProviders));
+});
+
+test("grants: unknown keys, id, user and business", () => {
+  refuses(() => checkAccess(mutated((d) => { d.grants[0].role = "x"; }), context()), /unsupported grants\[0\] key: "role"/);
+  refuses(() => checkAccess(mutated((d) => { d.grants[1].id = "g-1"; }), context()), /grants\[1\]\.id is a duplicate grant id: g-1/);
+  refuses(() => checkAccess(mutated((d) => { d.grants[0].id = "G 1"; }), context()), /grants\[0\]\.id must match/);
+  refuses(() => checkAccess(mutated((d) => { d.grants[0].user = "nobody"; }), context()), /grants\[0\]\.user must name a user in this file \(got "nobody"\)/);
+  refuses(() => checkAccess(mutated((d) => { d.grants[1].business = "other"; }), context()), /grants\[1\]\.business must name a declared business \(got "other"\)/);
+  refuses(() => checkAccess(mutated((d) => { d.grants[1].business = "constructor"; }), context()), /grants\[1\]\.business must name a declared business/);
+});
+
+test("grants: projects is [\"*\"] or distinct lowercase UUIDs", () => {
+  refuses(() => checkAccess(mutated((d) => { d.grants[1].projects = ["stack"]; }), context()), /grants\[1\]\.projects\[0\] must be "\*" or a bus project id, a lowercase UUID \(got "stack"\)/);
+  refuses(() => checkAccess(mutated((d) => { d.grants[1].projects = [P1.toUpperCase()]; }), context()), /grants\[1\]\.projects\[0\] must be "\*" or a bus project id/);
+  refuses(() => checkAccess(mutated((d) => { d.grants[1].projects = [P1, 7]; }), context()), /grants\[1\]\.projects\[1\] must be "\*" or a bus project id/);
+  refuses(() => checkAccess(mutated((d) => { d.grants[1].projects = ["*", P1]; }), context()), /grants\[1\]\.projects must be \["\*"\] alone/);
+  refuses(() => checkAccess(mutated((d) => { d.grants[1].projects = [P1, "*"]; }), context()), /grants\[1\]\.projects must be \["\*"\] alone/);
+  refuses(() => checkAccess(mutated((d) => { d.grants[1].projects = ["*", "*"]; }), context()), /grants\[1\]\.projects must be \["\*"\] alone/);
+  refuses(() => checkAccess(mutated((d) => { d.grants[1].projects = [P1, P1]; }), context()), /duplicate entry in grants\[1\]\.projects/);
+  refuses(() => checkAccess(mutated((d) => { d.grants[1].projects = []; }), context()), /grants\[1\]\.projects must not be empty/);
+  refuses(() => checkAccess(mutated((d) => { d.grants[1].projects = "*"; }), context()), /grants\[1\]\.projects must be an array/);
+  assert.ok(checkAccess(mutated((d) => { d.grants[1].projects = [P1, P2]; }), context()));
+});
+
+test("grants: instances is [\"*\"] or distinct declared instances of that business", () => {
+  refuses(() => checkAccess(mutated((d) => { d.grants[0].instances = ["coder"]; }), context()), /grants\[0\]\.instances\[0\] must be "\*" or a declared instance of creative-hub \(got "coder"\)/);
+  refuses(() => checkAccess(mutated((d) => { d.grants[0].instances = ["*", "writer"]; }), context()), /grants\[0\]\.instances must be \["\*"\] alone/);
+  refuses(() => checkAccess(mutated((d) => { d.grants[0].instances = ["writer", "writer"]; }), context()), /duplicate entry in grants\[0\]\.instances/);
+  refuses(() => checkAccess(mutated((d) => { d.grants[0].instances = []; }), context()), /grants\[0\]\.instances must not be empty/);
+  assert.ok(checkAccess(mutated((d) => { d.grants[0].instances = ["researcher", "writer"]; }), context()));
+});
+
+test("grants: any level other than collaborator refuses, naming grants[i].level", () => {
+  for (const bad of ["viewer", "owner", "Collaborator", "COLLABORATOR", "", null, 1]) {
+    refuses(() => checkAccess(mutated((d) => { d.grants[1].level = bad; }), context()), /grants\[1\]\.level must be one of collaborator/);
+  }
+  refuses(() => checkAccess(mutated((d) => { delete d.grants[0].level; }), context()), /grants\[0\]\.level must be one of collaborator \(got undefined\)/);
+});
+
+test("grants: expires is optional ISO time, and a past expiry is not refused", () => {
+  for (const bad of ["2026-12-31", "2026-12-31 00:00:00Z", "2026-12-31T00:00:00+01:00", "tomorrow", 1798675200000, null]) {
+    refuses(() => checkAccess(mutated((d) => { d.grants[0].expires = bad; }), context()), /grants\[0\]\.expires must be an ISO time/);
+  }
+  refuses(() => checkAccess(mutated((d) => { d.grants[0].expires = "2026-02-30T00:00:00Z"; }), context()), /grants\[0\]\.expires is not a real time/);
+  refuses(() => checkAccess(mutated((d) => { d.grants[0].expires = "2026-13-01T00:00:00Z"; }), context()), /grants\[0\]\.expires must be an ISO time/);
+  assert.ok(checkAccess(mutated((d) => { d.grants[0].expires = "2026-12-31T00:00:00.500Z"; }), context()));
+  // DESIGN 3.5: a grant past expires is treated as absent, not refused (sage-1399).
+  assert.ok(checkAccess(mutated((d) => { d.grants[0].expires = "2001-01-01T00:00:00Z"; }), context()));
+});
+
+test("the context is required and checked", () => {
+  refuses(() => checkAccess(doc()), /access context must be a JSON object/);
+  for (const key of ["providers", "peers", "ssoSubjects"]) {
+    const c = context();
+    delete c[key];
+    refuses(() => checkAccess(doc(), c), new RegExp(`access context\\.${key} must be an array`));
+  }
+  refuses(() => checkAccess(doc(), context({ businesses: [] })), /access context\.businesses must be a JSON object/);
+  refuses(() => checkAccess(doc(), context({ extra: 1 })), /unsupported access context key: "extra"/);
+  refuses(() => checkAccess(doc(), context({ peers: ["local"] })), /access context\.peers must not name "local"/);
+  refuses(() => checkAccess(doc(), context({ ssoSubjects: [{ provider: "authentik" }] })), /access context\.ssoSubjects\[0\]\.sub must be a non-empty string/);
+  refuses(() => checkAccess(doc(), context({ businesses: { acme: { human: "jason" } } })), /access context\.businesses\.acme\.instances must be an array/);
+});
+
+// loadAccess: the file checks, then checkAccess.
+
+test("loadAccess reads a valid file and checks it", () => {
+  const file = writeJson(join(tmp(), "access.json"), doc());
+  assert.deepEqual(loadAccess(file, context()), doc());
+});
+
+test("loadAccess refuses a missing file, a symlink and a directory with exit 4", () => {
+  const dir = tmp();
+  refuses(() => loadAccess(join(dir, "access.json"), context()), /access file not found/, 4);
+  const real = writeJson(join(dir, "real.json"), doc());
+  const link = join(dir, "access.json");
+  symlinkSync(real, link);
+  refuses(() => loadAccess(link, context()), /access file must be a regular, non-symbolic-link file/, 4);
+  const sub = join(dir, "d");
+  mkdirSync(sub);
+  refuses(() => loadAccess(sub, context()), /access file must be a regular, non-symbolic-link file/, 4);
+});
+
+test("loadAccess refuses another owner and group or other write", () => {
+  const file = writeJson(join(tmp(), "access.json"), doc());
+  refuses(() => loadAccess(file, context(), { uid: process.getuid() + 1 }), /access file must belong to uid/);
+  for (const mode of [0o620, 0o602, 0o666]) {
+    chmodSync(file, mode);
+    refuses(() => loadAccess(file, context()), /access file must not be writable by group or other/);
+  }
+  chmodSync(file, 0o644);
+  assert.ok(loadAccess(file, context()));
+});
+
+test("loadAccess refuses bad JSON and a bad document with exit 2", () => {
+  const dir = tmp();
+  refuses(() => loadAccess(writeJson(join(dir, "a.json"), "{"), context()), /access file is not valid JSON/);
+  refuses(() => loadAccess(writeJson(join(dir, "b.json"), mutated((d) => { d.grants[0].level = "owner"; })), context()), /grants\[0\]\.level/);
+});
+
+// covers.
+
+const NOW = new Date("2026-10-20T12:00:00Z");
+const target = (over = {}) => ({ business: "creative-hub", project: P1, instance: "researcher", ...over });
+
+test("covers: * and listed ids match", () => {
+  const [g1, g2] = checkAccess(doc(), context()).grants;
+  assert.equal(covers(g1, target({ project: P2 }), NOW), true);
+  assert.equal(covers(g2, target({ instance: "writer" }), NOW), true);
+  assert.equal(covers(g2, target(), NOW), true);
+});
+
+test("covers: an unlisted project, instance or business doesn't match", () => {
+  const [g1, g2] = checkAccess(doc(), context()).grants;
+  assert.equal(covers(g2, target({ project: P2 }), NOW), false);
+  assert.equal(covers(g1, target({ instance: "writer" }), NOW), false);
+  assert.equal(covers(g2, target({ business: "acme" }), NOW), false);
+  assert.equal(covers(g1, target({ business: "acme" }), NOW), false);
+});
+
+test("covers: an expired grant doesn't match, at and after the instant", () => {
+  const [g1, g2] = checkAccess(doc(), context()).grants;
+  assert.equal(covers(g1, target(), new Date("2026-12-30T23:59:59.999Z")), true);
+  assert.equal(covers(g1, target(), new Date("2026-12-31T00:00:00Z")), false);
+  assert.equal(covers(g1, target(), new Date("2027-01-01T00:00:00Z")), false);
+  // No expires never expires.
+  assert.equal(covers(g2, target(), new Date("2099-01-01T00:00:00Z")), true);
+});
+
+test("covers: a level filter rejects another level, and no filter accepts any", () => {
+  const g = checkAccess(doc(), context()).grants[0];
+  assert.equal(covers(g, target(), NOW, { level: "collaborator" }), true);
+  assert.equal(covers(g, target(), NOW, {}), true);
+  assert.equal(covers(g, target(), NOW, { level: "viewer" }), false);
+  assert.equal(covers({ ...g, level: "viewer" }, target(), NOW, { level: "collaborator" }), false);
+});
+
+test("covers: now must be a valid Date", () => {
+  const g = checkAccess(doc(), context()).grants[0];
+  assert.throws(() => covers(g, target(), Date.now()), TypeError);
+  assert.throws(() => covers(g, target(), new Date("nope")), TypeError);
+});

packages/cli/README.md

@@ -1009,6 +1009,35 @@ names no one; the restart itself needs Mos's go or Jason's hand. A vars or launc
 prints `no restart`, because the launcher reads it at its next launch check.
 The Console Settings page has the same read and write (`packages/webui`).
 
+## Access (FED R5, #414)
+
+```
+mosaic access list --business ID [--json]
+mosaic access grant --business ID --user ID --projects UUID|NAME,...|* --instances NAME,...|* --level collaborator [--expires ISO] --revision N
+mosaic access revoke --business ID --user ID [--grant GID] --revision N
+```
+
+These edit `<configDir>/access.json` (design section 3.5). The human proof is one `project.list`
+call through the human transport: the bus gates it with `#human` (`packages/bus/src/broker.mjs`,
+the `project.list` case and `#human`). An agent, or `--tester`, is refused before any write. Each
+write runs the file's checks on the new document first, bumps the revision by one, and renames
+atomically. A `--revision` that is not the file's current revision refuses with `revision-conflict`.
+A writer that finds the lock refuses at once. A lock whose pid is gone, or that is empty or
+unreadable, also refuses, and nothing reclaims it: check that no write is running, then remove
+`<configDir>/access.json.lock` by hand. Each write appends one receipt line to
+`<dataRoot>/state/access-log.jsonl`.
+
+The command runs as the instance's uid. `access.json` must belong to that uid and must not be
+writable by group or other. If it is not, or a business file fails to load, the command refuses
+with exit 3, names the file and the key path, and writes nothing.
+
+A grant's `instances` is the real limit. The granted instance runs with the owner's role, so a
+collaborator's message drives it with that authority. To cut a user off, revoke first: it acts at
+once. Removing a provider from `console.sso` takes effect only after a Console restart.
+
+Peer homes are not read yet, so a grant that names a peer home refuses until row 203 adds the
+federation key. A grant that names a sign-in subject needs `console.sso` in the system config.
+
 ## Token usage
 
 `mosaic usage [--business ID] [--json] [--tester]` reads the bus's accounting, without

packages/cli/src/access.mjs

@@ -0,0 +1,288 @@
+// `mosaic access list|grant|revoke` (federation design section 3.5, FED R5, #414).
+// The human edits <configDir>/access.json here. Each write is checked against the
+// instance's context before it lands, bumps the revision by one, and appends one
+// receipt line to <dataRoot>/state/access-log.jsonl. The human proof is one call
+// through humanTransport: a bus that does not see a human shell refuses it, so
+// no agent and no tester can write. The context (providers, peers, businesses,
+// ssoSubjects) comes in as a function; the caller decides where it comes from.
+
+import { appendFileSync, mkdirSync, readdirSync, readFileSync, renameSync, openSync, writeSync, fsyncSync, closeSync, existsSync, unlinkSync } from "node:fs";
+import { randomBytes } from "node:crypto";
+import { join, dirname } from "node:path";
+import { BusinessError, accessFilePath, checkAccess, configDir, loadAccess, loadBusiness, LEVELS } from "../../business/src/index.mjs";
+import { rolesDir } from "./config.mjs";
+import { CliError } from "./errors.mjs";
+import { refuseInsideAgent } from "./transport.mjs";
+
+export const ACCESS_USAGE = [
+  "mosaic access list --business ID [--json]",
+  "mosaic access grant --business ID --user ID --projects UUID|NAME,...|* --instances NAME,...|* --level collaborator [--expires ISO] --revision N",
+  "mosaic access revoke --business ID --user ID [--grant GID] --revision N",
+].join("\n");
+
+// The help text. A grant's `instances` is the real limit: the granted instance
+// runs with the owner's role, so a collaborator drives it with that authority.
+// Removing a user acts at once. Removing a provider from console.sso waits for a
+// Console restart, so take the users out of access.json first. Peer homes are
+// empty until the federation key lands (row 203), so a grant naming a peer
+// home refuses until then. A grant naming a subject needs console.sso.
+export const ACCESS_HELP = `${ACCESS_USAGE}
+
+A grant gives a user exactly what the granted instances can do. The instances
+list is the real limit: a collaborator's message drives a granted instance with
+the owner's role.
+To cut a user off, revoke them here first. It acts at once. Removing a provider
+from console.sso takes effect only after a Console restart, so do that second.
+Peer homes are not read yet (row 203 adds the federation key), so a grant that
+names a peer home refuses. A grant that names a sign-in subject needs console.sso
+in the system config; without it every such grant refuses.
+The command runs as the instance's uid: access.json must belong to it and must
+not be writable by group or other, or the command refuses (exit 3) and writes nothing.`;
+
+// The instance's context for checkAccess, read from the system config and the business
+// files. providers and ssoSubjects come from console.sso (row 192's shape: each provider
+// has an id and a subjects list). peers is empty until row 203. A business file that
+// fails to load fails the whole command.
+export function accessContextFor(system, env) {
+  const providers = system.console?.sso?.providers ?? [];
+  const ssoSubjects = providers.flatMap((p) => p.subjects.map((s) => ({ provider: p.id, sub: s.sub })));
+  const dir = join(configDir(env), "businesses");
+  const businesses = {};
+  if (existsSync(dir)) {
+    for (const file of readdirSync(dir).filter((f) => f.endsWith(".json")).sort()) {
+      const id = file.slice(0, -".json".length);
+      const doc = loadBusiness(id, { dir: configDir(env), rolesDir: rolesDir(env) });
+      businesses[id] = { human: doc.human, instances: Object.keys(doc.roles) };
+    }
+  }
+  return { providers: providers.map((p) => p.id), peers: [], businesses, ssoSubjects };
+}
+
+// Every verb needs --business: the human proof runs through that business's bus.
+// --tester is refused outright on every verb, before any bus call.
+function parse(args) {
+  const out = { positional: [], flags: new Set(), values: {} };
+  for (let i = 0; i < args.length; i++) {
+    const a = args[i];
+    if (a === "--json" || a === "--tester") out.flags.add(a);
+    else if (a.startsWith("--")) {
+      if (i + 1 >= args.length || args[i + 1].startsWith("--")) throw new CliError(`${a} needs one value\n${ACCESS_USAGE}`, 4);
+      out.values[a] = args[++i];
+    } else out.positional.push(a);
+  }
+  return out;
+}
+
+const list = (value) => (value === "*" ? ["*"] : value.split(",").filter(Boolean));
+
+function readCurrent(file, context) {
+  if (!existsSync(file)) return { document: { accessVersion: 1, revision: null, users: [], grants: [] }, revision: 0 };
+  const document = loadAccess(file, context);
+  return { document, revision: document.revision };
+}
+
+// The file calls the write path makes. A test passes a stand-in through deps.fs.
+const realFs = { openSync, writeSync, fsyncSync, closeSync, renameSync, unlinkSync };
+
+// Atomic write: a temp file in the same directory, 0600, fsynced, then renamed over
+// the old file. A reader sees the old bytes or the new bytes, never a mix. A failure
+// before or at the rename removes the temp file and leaves the old bytes in place.
+function writeAtomic(file, text, fs = realFs) {
+  const tmp = join(dirname(file), `.access-${randomBytes(8).toString("hex")}.tmp`);
+  try {
+    const fd = fs.openSync(tmp, "wx", 0o600);
+    try {
+      fs.writeSync(fd, text);
+      fs.fsyncSync(fd);
+    } finally {
+      fs.closeSync(fd);
+    }
+    fs.renameSync(tmp, file);
+  } catch (error) {
+    try {
+      fs.unlinkSync(tmp);
+    } catch {
+      // Already gone: the temp file was never created.
+    }
+    throw error;
+  }
+}
+
+function receipt(dataRoot, line) {
+  const dir = join(dataRoot, "state");
+  mkdirSync(dir, { recursive: true });
+  appendFileSync(join(dir, "access-log.jsonl"), `${JSON.stringify(line)}\n`, { mode: 0o600 });
+}
+
+// Two writers never interleave: the read, the check and the rename happen under an
+// exclusive lock file, `<access.json>.lock`, mode 0600. The file holds the holder's
+// pid and a newline. A lock whose holder is alive refuses. A lock that is empty,
+// unreadable, or whose pid is gone also refuses, and nothing reclaims it: a human
+// removes it once no write is running. Fail closed, with no reclaim race.
+const BUSY = "refused: the access file is being written by another command; try again";
+
+function lockPid(lock) {
+  let text;
+  try {
+    text = readFileSync(lock, "utf8");
+  } catch {
+    return null;
+  }
+  const pid = Number(text.trim());
+  return Number.isSafeInteger(pid) && pid >= 1 ? pid : null;
+}
+
+function pidAlive(pid) {
+  try {
+    process.kill(pid, 0);
+    return true;
+  } catch (error) {
+    return error.code !== "ESRCH";
+  }
+}
+
+function lockRefusal(lock) {
+  const pid = lockPid(lock);
+  if (pid !== null && pidAlive(pid)) return BUSY;
+  if (pid === null) return `refused: lock ${lock} is unreadable or not a pid; if no write is running, remove it by hand and try again`;
+  return `refused: lock ${lock} is left by pid ${pid}, which is not running; if no write is running, remove it by hand and try again`;
+}
+
+function takeLock(lock, fs) {
+  try {
+    return fs.openSync(lock, "wx", 0o600);
+  } catch (error) {
+    if (error.code !== "EEXIST") throw error;
+  }
+  throw new CliError(lockRefusal(lock), 3);
+}
+
+export function withLock(file, fn, fs = realFs) {
+  const lock = `${file}.lock`;
+  const fd = takeLock(lock, fs);
+  try {
+    fs.writeSync(fd, `${process.pid}\n`);
+  } finally {
+    fs.closeSync(fd);
+  }
+  try {
+    return fn();
+  } finally {
+    fs.unlinkSync(lock);
+  }
+}
+
+// The one human-proof call: project.list, which the bus gates with #human
+// (broker.mjs:2319, and #human at :377). It also returns the rows that resolve
+// project names. Row R4 swaps this call for access.reload.
+async function proveHuman(transport, business) {
+  return transport(business)("project.list", {});
+}
+
+// Resolve a --projects item: "*" and UUIDs pass through, anything else is a project
+// name looked up in project.list at grant time (the id is what gets written).
+function resolveProjects(items, rows) {
+  return items.map((item) => {
+    if (item === "*" || /^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$/.test(item)) return item;
+    const hits = rows.filter((r) => r.name === item);
+    if (hits.length !== 1) throw new CliError(`refused: project-not-found: no project named ${item} in this business (or the name is ambiguous)`, 2);
+    return hits[0].id;
+  });
+}
+
+// deps: { system: { dataRoot }, transport(business) -> call(verb, args), contextFor() -> context, configDir?, now?, fs? }
+export async function accessCommand(args, io, deps) {
+  refuseInsideAgent(io.env);
+  try {
+    return await accessVerb(args, io, deps);
+  } catch (error) {
+    // A file or business doc the checks refuse to load (group-writable, a wrong uid, a
+    // hand edit) is a refusal with exit 3 and the file and key path, not a crash.
+    if (error instanceof BusinessError) throw new CliError(`refused: ${error.message}`, 3);
+    throw error;
+  }
+}
+
+async function accessVerb(args, io, deps) {
+  const parsed = parse(args);
+  const sub = parsed.positional[0];
+  if (!["list", "grant", "revoke"].includes(sub) || parsed.positional.length !== 1) throw new CliError(ACCESS_HELP, 4);
+  if (parsed.flags.has("--tester")) throw new CliError("refused: access writes take the human's shell, not --tester", 3);
+  const business = parsed.values["--business"];
+  if (!business) throw new CliError(`--business is required\n${ACCESS_USAGE}`, 4);
+
+  const rows = await proveHuman(deps.transport, business);
+  const file = deps.file ?? accessFilePath(deps.configDir ?? configDir(io.env));
+  // Built after the human proof, so a refused caller never reads the business files.
+  const context = deps.contextFor();
+
+  if (sub === "list") {
+    const { document } = readCurrent(file, context);
+    io.stdout.write(parsed.flags.has("--json") ? `${JSON.stringify(document, null, 2)}\n` : formatList(document));
+    return;
+  }
+
+  const expected = parsed.values["--revision"];
+  if (!/^\d+$/.test(expected ?? "")) throw new CliError(`--revision takes the revision you read\n${ACCESS_USAGE}`, 4);
+  const user = parsed.values["--user"];
+  if (!user) throw new CliError(`${sub} needs --user\n${ACCESS_USAGE}`, 4);
+
+  const result = withLock(file, () => {
+    const { document, revision } = readCurrent(file, context);
+    if (Number(expected) !== revision) {
+      throw new CliError(`refused: revision-conflict: the access file is at revision ${revision}, not ${expected}; run list again`, 3);
+    }
+    let next;
+    let touched;
+    if (sub === "grant") {
+      const level = parsed.values["--level"];
+      if (!parsed.values["--projects"] || !parsed.values["--instances"] || level === undefined) {
+        throw new CliError(`grant needs --projects, --instances and --level\n${ACCESS_USAGE}`, 4);
+      }
+      if (!LEVELS.includes(level)) throw new CliError(`--level takes ${LEVELS.join(", ")}`, 2);
+      const id = `g-${randomBytes(4).toString("hex")}`;
+      const grant = {
+        id,
+        user,
+        business,
+        projects: resolveProjects(list(parsed.values["--projects"]), rows),
+        instances: list(parsed.values["--instances"]),
+        level,
+      };
+      if (parsed.values["--expires"] !== undefined) grant.expires = parsed.values["--expires"];
+      touched = [id];
+      next = { ...document, revision: revision + 1, grants: [...document.grants, grant] };
+    } else {
+      const only = parsed.values["--grant"];
+      const drop = (g) => g.user === user && g.business === business && (only === undefined || g.id === only);
+      touched = document.grants.filter(drop).map((g) => g.id);
+      if (touched.length === 0) throw new CliError(`refused: no grant for ${user} at ${business} to revoke`, 2);
+      next = { ...document, revision: revision + 1, grants: document.grants.filter((g) => !drop(g)) };
+    }
+    // Every check runs on the new document before a byte is written.
+    const checked = checkAccess(next, context);
+    writeAtomic(file, `${JSON.stringify(checked, null, 2)}\n`, deps.fs);
+    return { checked, revision, touched };
+  }, deps.fs);
+
+  receipt(deps.system.dataRoot, {
+    at: (deps.now ?? (() => new Date()))().toISOString(),
+    verb: sub,
+    business,
+    user,
+    actor: "human",
+    revisionBefore: result.revision,
+    revisionAfter: result.checked.revision,
+    grants: result.touched,
+  });
+  io.stdout.write(`access ${sub}: ${result.touched.join(", ")} at ${business}, revision ${result.checked.revision}\n`);
+}
+
+function formatList(doc) {
+  const lines = [`access file revision ${doc.revision ?? "none"}`];
+  for (const u of doc.users) lines.push(`user ${u.id} home ${u.home}`);
+  for (const g of doc.grants) {
+    lines.push(`grant ${g.id} user ${g.user} business ${g.business} projects ${g.projects.join(",")} instances ${g.instances.join(",")} level ${g.level}${g.expires ? ` expires ${g.expires}` : ""}`);
+  }
+  return `${lines.join("\n")}\n`;
+}

packages/cli/src/cli.mjs

@@ -18,6 +18,7 @@ import { resolveThread, threadCommand, threadMembers, threadsCommand, THREAD_TAL
 import { limitsCommand, LIMITS_USAGE } from "./limits.mjs";
 import { pluginsCommand, PLUGINS_USAGE } from "./plugins.mjs";
 import { instancesCommand, INSTANCES_USAGE } from "./instances.mjs";
+import { accessCommand, accessContextFor } from "./access.mjs";
 import { createChannelCaller } from "../../plugins/src/channel.mjs";
 import { PluginError } from "../../plugins/src/kinds.mjs";
 import { CliError } from "./errors.mjs";
@@ -573,6 +574,15 @@ export async function main(argv, io = { env: process.env, stdin: process.stdin,
   if (verb === "project") return ["create", "list"].includes(rest[0]) ? projectBusCommand(rest, io, (p) => channelCallFor(p, io, deps)) : projectCommand(rest, io, deps, (p) => callFor(p, io, deps));
   if (verb === "threads") return threadsCommand(rest, io, (p) => channelCallFor(p, io, deps));
   if (verb === "thread") return threadCommand(rest, io, (p) => channelCallFor(p, io, deps), formatMessage);
+  if (verb === "access") {
+    const system = deps.system ?? loadSystem({ env: io.env });
+    return accessCommand(rest, io, {
+      system,
+      transport: (b) => humanTransport({ socket: socketPath(system.dataRoot), business: b, env: io.env }),
+      contextFor: () => deps.accessContext ?? accessContextFor(system, io.env),
+      now: deps.now,
+    });
+  }
   if (verb === "limits") return limitsCommand(rest,io,p=>callFor(p,io,deps));
   if (verb === "usage") return usageCommand(rest, io, p => callFor(p, io, deps));
   if (verb === "plugins") return pluginsCommand(rest, io, (p) => callFor(p, io, deps));

packages/cli/tests/access.test.mjs

@@ -0,0 +1,306 @@
+// `mosaic access` (FED R5, #414). Every write goes to a scratch config dir and a
+// scratch data root. The success paths run on a stand-in human CLI (fakeCli).
+// The one test that runs the real human-cli.mjs does it on a scratch bus from
+// agent ancestry, so the bus must refuse, and nothing is written.
+import test from "node:test";
+import assert from "node:assert/strict";
+import { spawnSync } from "node:child_process";
+import * as nodeFs from "node:fs";
+import { chmodSync, existsSync, mkdirSync, readFileSync, readdirSync, statSync, writeFileSync } from "node:fs";
+import { join } from "node:path";
+import { startBroker } from "../../bus/src/runtime.mjs";
+import { accessCommand, accessContextFor, withLock } from "../src/access.mjs";
+import { CliError } from "../src/errors.mjs";
+import { socketPath } from "../src/config.mjs";
+import { HUMAN_CLI, humanTransport } from "../src/transport.mjs";
+import { fakeCli, humanEnv, io, tmp, fixture } from "./helpers.mjs";
+import { systemFor, writeJson } from "../../business/tests/helpers.mjs";
+
+const PROJECT = "3f1c2a64-0d8e-4b7a-9c55-1a2b3c4d5e6f";
+const ROWS = [{ id: PROJECT, name: "hub", repo: null }];
+const CONTEXT = {
+  providers: ["authentik"],
+  peers: [],
+  businesses: { acme: { human: "jason", instances: ["coder"] } },
+  ssoSubjects: [{ provider: "authentik", sub: "jason-sub" }],
+};
+const DOC = {
+  accessVersion: 1,
+  revision: 1,
+  users: [{ id: "alice", home: "local", subjects: [{ provider: "authentik", sub: "alice-sub" }] }],
+  grants: [],
+};
+
+// The stand-in human CLI. It answers project.list with ROWS, or refuses like a bus
+// that sees no human shell when FAKE_MODE is "refuse".
+const BODY = `
+import { readFileSync, writeFileSync } from "node:fs";
+const input = JSON.parse(readFileSync(0, "utf8"));
+writeFileSync(process.env.FAKE_LOG, JSON.stringify(input));
+if (process.env.FAKE_MODE === "refuse") { process.stderr.write("human-required\\n"); process.exit(3); }
+process.stdout.write(JSON.stringify(${JSON.stringify(ROWS)}));
+`;
+
+function setup(t, { mode = "ok", doc = DOC } = {}) {
+  const root = tmp(t, "mosaic-access-");
+  const config = join(root, "config");
+  mkdirSync(config, { recursive: true });
+  const dataRoot = join(root, "data");
+  const log = join(root, "fake.log");
+  const cli = fakeCli(root, BODY);
+  const env = humanEnv({ FAKE_LOG: log, FAKE_MODE: mode });
+  const file = join(config, "access.json");
+  if (doc) writeFileSync(file, JSON.stringify(doc, null, 2), { mode: 0o600 });
+  const deps = {
+    system: { dataRoot },
+    configDir: config,
+    contextFor: () => CONTEXT,
+    now: () => new Date("2026-10-20T20:00:00Z"),
+    transport: (business) => humanTransport({ socket: join(root, "bus.sock"), business, env, cli, timeoutMs: 5000 }),
+  };
+  const receipts = () => (existsSync(join(dataRoot, "state", "access-log.jsonl")) ? readFileSync(join(dataRoot, "state", "access-log.jsonl"), "utf8") : "");
+  return { root, config, file, deps, env, log, receipts, read: () => JSON.parse(readFileSync(file, "utf8")) };
+}
+
+const GRANT_BASE = ["grant", "--business", "acme", "--user", "alice"];
+const GRANT = [...GRANT_BASE, "--projects", PROJECT, "--instances", "coder", "--level", "collaborator"];
+
+async function run(args, deps, env = humanEnv()) {
+  const i = io(env);
+  await accessCommand(args, i, deps);
+  return i.out.text;
+}
+
+async function refusal(promise, pattern) {
+  await assert.rejects(promise, (e) => e instanceof CliError && pattern.test(e.message));
+  return promise.catch((e) => e);
+}
+
+test("list prints the revision and the users", async (t) => {
+  const s = setup(t);
+  const out = await run(["list", "--business", "acme"], s.deps);
+  assert.match(out, /access file revision 1/);
+  assert.match(out, /user alice home local/);
+});
+
+test("grant writes one revision up, a receipt line, and the id in the file", async (t) => {
+  const s = setup(t);
+  const out = await run([...GRANT, "--revision", "1"], s.deps);
+  assert.match(out, /access grant: g-[0-9a-f]{8} at acme, revision 2/);
+  const doc = s.read();
+  assert.equal(doc.revision, 2);
+  assert.equal(doc.grants.length, 1);
+  assert.deepEqual(doc.grants[0].projects, [PROJECT]);
+  const [line] = s.receipts().trim().split("\n").map((l) => JSON.parse(l));
+  assert.equal(line.verb, "grant");
+  assert.equal(line.revisionBefore, 1);
+  assert.equal(line.revisionAfter, 2);
+  assert.equal(line.actor, "human");
+});
+
+test("a second write appends a second receipt and leaves the first intact", async (t) => {
+  const s = setup(t);
+  await run([...GRANT, "--revision", "1"], s.deps);
+  await run(["revoke", "--business", "acme", "--user", "alice", "--revision", "2"], s.deps);
+  const lines = s.receipts().trim().split("\n").map((l) => JSON.parse(l));
+  assert.deepEqual(lines.map((l) => l.verb), ["grant", "revoke"]);
+  assert.equal(lines[0].revisionAfter, 2);
+});
+
+test("a stale revision refuses with revision-conflict and writes nothing", async (t) => {
+  const s = setup(t);
+  await run([...GRANT, "--revision", "1"], s.deps);
+  const before = readFileSync(s.file, "utf8");
+  await refusal(run([...GRANT, "--revision", "1"], s.deps), /revision-conflict/);
+  assert.equal(readFileSync(s.file, "utf8"), before);
+  assert.equal(s.receipts().trim().split("\n").length, 1);
+});
+
+test("a live holder's lock refuses and leaves the file and the lock alone", async (t) => {
+  const s = setup(t);
+  writeFileSync(`${s.file}.lock`, `${process.pid}\n`, { mode: 0o600 });
+  const before = readFileSync(s.file, "utf8");
+  await refusal(run([...GRANT, "--revision", "1"], s.deps), /being written by another command/);
+  assert.equal(readFileSync(s.file, "utf8"), before);
+  assert.equal(readFileSync(`${s.file}.lock`, "utf8"), `${process.pid}\n`);
+  assert.equal(readdirSync(s.config).filter((f) => f.startsWith(".access-")).length, 0);
+});
+
+test("an empty or unreadable lock refuses, since its holder may still be writing", async (t) => {
+  const s = setup(t);
+  writeFileSync(`${s.file}.lock`, "");
+  await refusal(run([...GRANT, "--revision", "1"], s.deps), /is unreadable or not a pid/);
+  writeFileSync(`${s.file}.lock`, "not-a-pid\n");
+  await refusal(run([...GRANT, "--revision", "1"], s.deps), /is unreadable or not a pid/);
+  assert.equal(existsSync(`${s.file}.lock`), true);
+});
+
+test("a lock left by a dead pid refuses, names the pid, and is not reclaimed", async (t) => {
+  const s = setup(t);
+  const dead = spawnSync(process.execPath, ["-e", ""]);
+  writeFileSync(`${s.file}.lock`, `${dead.pid}\n`, { mode: 0o600 });
+  const before = readFileSync(s.file, "utf8");
+  await refusal(run([...GRANT, "--revision", "1"], s.deps), new RegExp(`${s.file}\\.lock is left by pid ${dead.pid}, which is not running`));
+  assert.equal(readFileSync(s.file, "utf8"), before);
+  assert.equal(readFileSync(`${s.file}.lock`, "utf8"), `${dead.pid}\n`);
+  assert.equal(s.receipts(), "");
+});
+
+test("a failed rename leaves the old bytes, removes the temp file, and writes no receipt", async (t) => {
+  const s = setup(t);
+  const before = readFileSync(s.file, "utf8");
+  const fs = { ...nodeFs, renameSync: () => { throw Object.assign(new Error("injected rename failure"), { code: "EXDEV" }); } };
+  await assert.rejects(run([...GRANT, "--revision", "1"], { ...s.deps, fs }), /injected rename failure/);
+  assert.equal(readFileSync(s.file, "utf8"), before);
+  assert.deepEqual(readdirSync(s.config).filter((f) => f.startsWith(".access-")), []);
+  assert.equal(existsSync(`${s.file}.lock`), false);
+  assert.equal(s.receipts(), "");
+});
+
+test("a group-writable access file refuses with exit 3, names the file, and changes nothing", async (t) => {
+  const s = setup(t);
+  chmodSync(s.file, 0o664);
+  const before = readFileSync(s.file, "utf8");
+  const err = await refusal(run([...GRANT, "--revision", "1"], s.deps), /must not be writable by group or other/);
+  assert.equal(err.exitCode, 3);
+  assert.match(err.message, new RegExp(s.file.replace(/[.*+?^${}()|[\]\\]/g, "\\$&")));
+  assert.equal(readFileSync(s.file, "utf8"), before);
+  assert.equal(s.receipts(), "");
+  assert.equal(existsSync(`${s.file}.lock`), false);
+});
+
+test("an agent or tester caller is refused before the context or the access file is read", async (t) => {
+  const s = setup(t);
+  chmodSync(s.file, 0o664);
+  const deps = { ...s.deps, contextFor: () => { throw new Error("context was read"); } };
+  const env = { ...humanEnv(), MOSAIC_RUN_ID: "run-1" };
+  await refusal(run([...GRANT, "--revision", "1"], deps, env), /human shell/);
+  await refusal(run(["list", "--business", "acme", "--tester"], deps), /not --tester/);
+});
+
+test("the lock is mode 0600 while held and removed after a refused write", async (t) => {
+  const s = setup(t);
+  let mode;
+  withLock(s.file, () => {
+    mode = statSync(`${s.file}.lock`).mode & 0o777;
+  });
+  assert.equal(mode, 0o600);
+  assert.equal(existsSync(`${s.file}.lock`), false);
+  await refusal(run([...GRANT, "--revision", "9"], s.deps), /revision-conflict/);
+  assert.equal(existsSync(`${s.file}.lock`), false);
+});
+
+test("a grant naming an unknown instance is refused before any write", async (t) => {
+  const s = setup(t);
+  const before = readFileSync(s.file, "utf8");
+  const bad = [...GRANT_BASE, "--projects", PROJECT, "--instances", "nobody", "--level", "collaborator", "--revision", "1"];
+  await refusal(run(bad, s.deps), /refused: /);
+  assert.equal(readFileSync(s.file, "utf8"), before);
+  assert.equal(s.receipts(), "");
+});
+
+test("a project name resolves to its id at grant time", async (t) => {
+  const s = setup(t);
+  const args = [...GRANT_BASE, "--projects", "hub", "--instances", "coder", "--level", "collaborator", "--revision", "1"];
+  await run(args, s.deps);
+  assert.deepEqual(s.read().grants[0].projects, [PROJECT]);
+});
+
+test("an unknown project name refuses before any write", async (t) => {
+  const s = setup(t);
+  const before = readFileSync(s.file, "utf8");
+  const args = [...GRANT_BASE, "--projects", "nope", "--instances", "coder", "--level", "collaborator", "--revision", "1"];
+  await refusal(run(args, s.deps), /project-not-found/);
+  assert.equal(readFileSync(s.file, "utf8"), before);
+});
+
+test("revoke removes the user's grants and leaves a revision behind", async (t) => {
+  const s = setup(t);
+  await run([...GRANT, "--revision", "1"], s.deps);
+  await run(["revoke", "--business", "acme", "--user", "alice", "--revision", "2"], s.deps);
+  const doc = s.read();
+  assert.equal(doc.revision, 3);
+  assert.deepEqual(doc.grants, []);
+});
+
+test("revoke of a user with no grant refuses and writes nothing", async (t) => {
+  const s = setup(t);
+  const before = readFileSync(s.file, "utf8");
+  await refusal(run(["revoke", "--business", "acme", "--user", "alice", "--revision", "1"], s.deps), /no grant/);
+  assert.equal(readFileSync(s.file, "utf8"), before);
+});
+
+test("an agent caller is refused before the bus is asked", async (t) => {
+  const s = setup(t);
+  const before = readFileSync(s.file, "utf8");
+  const env = { ...humanEnv(), MOSAIC_RUN_ID: "run-1" };
+  const err = await refusal(run([...GRANT, "--revision", "1"], s.deps, env), /human shell/);
+  assert.equal(err.exitCode, 3);
+  assert.equal(existsSync(s.log), false);
+  assert.equal(readFileSync(s.file, "utf8"), before);
+});
+
+test("--tester is refused on every verb before the bus is asked", async (t) => {
+  const s = setup(t);
+  for (const verb of [["list"], [...GRANT, "--revision", "1"], ["revoke", "--user", "alice", "--revision", "1"]]) {
+    const args = [...verb, "--business", "acme", "--tester"];
+    const err = await refusal(run(args, s.deps), /not --tester/);
+    assert.equal(err.exitCode, 3);
+  }
+  assert.equal(existsSync(s.log), false);
+});
+
+test("a bus that refuses the human proof blocks the write", async (t) => {
+  const s = setup(t, { mode: "refuse" });
+  const before = readFileSync(s.file, "utf8");
+  const err = await refusal(run([...GRANT, "--revision", "1"], s.deps), /human-required/);
+  assert.equal(err.exitCode, 3);
+  assert.equal(readFileSync(s.file, "utf8"), before);
+  assert.equal(s.receipts(), "");
+});
+
+test("the context reads console.sso subjects and the business files, and peers stay empty", async (t) => {
+  const root = tmp(t, "mosaic-access-ctx-");
+  const f = fixture(root, "acme");
+  const system = { console: { sso: { providers: [{ id: "authentik", subjects: [{ sub: "jason-sub" }] }] } } };
+  const ctx = accessContextFor(system, { MOSAIC_CONFIG: join(root, "config", "config.json") });
+  assert.deepEqual(ctx.providers, ["authentik"]);
+  assert.deepEqual(ctx.ssoSubjects, [{ provider: "authentik", sub: "jason-sub" }]);
+  assert.deepEqual(ctx.peers, []);
+  assert.equal(ctx.businesses.acme.human, "jason");
+  assert.ok(Array.isArray(ctx.businesses.acme.instances) && ctx.businesses.acme.instances.length > 0);
+  const bare = accessContextFor({}, { MOSAIC_CONFIG: join(root, "config", "config.json") });
+  assert.deepEqual(bare.ssoSubjects, []);
+  assert.deepEqual(bare.providers, []);
+});
+
+// Real human-cli.mjs on a scratch bus, run from agent ancestry. The proof must fail.
+test("the real human-cli, run from agent ancestry, refuses and writes nothing", async (t) => {
+  const root = tmp(t, "mosaic-access-real-");
+  const f = fixture(root, "acme");
+  const config = join(root, "config");
+  const bus = await startBroker({
+    dataRoot: f.dataRoot,
+    businesses: { acme: { id: "acme", human: "jason", arbiters: { technical: "coder", delivery: "coder" }, roles: { coder: { authority: { withinRole: [], crossRole: [] } } } } },
+    organization: { dir: config, rolesDir: f.roles, system: systemFor(root) },
+  });
+  t.after(() => bus.close());
+  writeJson(join(config, "access.json"), DOC);
+  const file = join(config, "access.json");
+  const before = readFileSync(file, "utf8");
+  const agentEnv = { ...humanEnv(), CLAUDECODE: "1" };
+  const deps = {
+    system: { dataRoot: f.dataRoot },
+    configDir: config,
+    contextFor: () => CONTEXT,
+    transport: (business) => humanTransport({ socket: socketPath(f.dataRoot), business, env: agentEnv, cli: HUMAN_CLI, timeoutMs: 10000 }),
+  };
+  // The bus closes the socket on a failed human proof, so the client reports
+  // outcome-unknown (client.mjs:32-33), not human-required. That is a bus behavior
+  // outside R5 (BUILD.md). The test pins it, and nothing is written.
+  const err = await refusal(run([...GRANT, "--revision", "1"], deps), /^outcome-unknown/);
+  assert.equal(err.code, "outcome-unknown");
+  assert.equal(err.exitCode, 1);
+  assert.equal(readFileSync(file, "utf8"), before);
+  assert.equal(existsSync(join(f.dataRoot, "state", "access-log.jsonl")), false);
+});

scripts/mosaic

@@ -35,6 +35,6 @@ if [ "${1:-}" = business ]; then
   exec node "$REPO/packages/business/src/cli.mjs" "$@"
 fi
 case "${1:-}" in
-  usage|project|limits|inbox|decide|tasks|agents|trail|talk|stop|launches|bus|plugins|name|names|follow|threads|thread) exec node "$REPO/packages/cli/src/cli.mjs" "$@" ;;
+  usage|project|limits|inbox|decide|tasks|agents|trail|talk|stop|launches|bus|plugins|name|names|follow|threads|thread|access) exec node "$REPO/packages/cli/src/cli.mjs" "$@" ;;
 esac
 exec node "$REPO/packages/seat/src/cli.mjs" "$@"