---
id: SEAT.1
status: ratified
ratified: 2026-09-01 (Jason Woltje; PRD rev1 ratification PR)
---

# SEAT.1 — Seat identity, profile, and configuration

## Instance contract (register OD-48)

| File                   | Carries                                                                                                          |
| ---------------------- | ---------------------------------------------------------------------------------------------------------------- |
| `profile.json`         | structured identity — and, post-consolidation, the full seat record ([[DATA.1-record-authority]] §consolidation) |
| `overlay.json`         | generated composition                                                                                            |
| seat-local `AGENTS.md` | narrative specialization                                                                                         |
| `SOUL.md`              | persona                                                                                                          |

## Seat configuration surface (WebUI page + CLI)

| Control                | Notes                                                                                 |
| ---------------------- | ------------------------------------------------------------------------------------- |
| harness                | from **enabled** harnesses only ([[HARN.1-harness-config]])                           |
| model                  | constrained by the harness's available-models allowlist                               |
| reasoning level        |                                                                                       |
| work dir               |                                                                                       |
| authentication account | from configured, active accounts allowed for that harness ([[AUTHN.1-auth-accounts]]) |
| overlay                | per-seat overlay only — never the role file (ROLE separation rule)                    |
| role binding           | **separated section — see below**                                                     |

## The role-binding control (gap G5)

Role Binding is the single highest-authority action in the system,
principal-only under L2-D13. `model` is a preference. They must not share one
undifferentiated form — a privilege grant must not inherit the ceremony of a
dropdown. Requirements:

- Visually and structurally separate section on the page.
- Distinct confirmation step; re-authentication of the principal is under
  consideration ([[GOV.5-open-questions]] Q-S2).
- Register OD-02/OD-03 bind the semantics: a seat has exactly one role; an
  **active session never switches roles**. A role change reconfigures the
  existing seat, preserves identity and history, **discards ephemeral context,
  and starts a clean session**. The surface must say so before confirming.
- Role-transition history is recorded: old role, new role, reason, authorizer,
  checkpoint, activation time (register OD-04).

Role changes are therefore a _different operation_ from harness/model/provider
changes ([[SESS.1-session-continuity]]) and must not share a code path.

## Seat identity and credential rules (pulled 2026-08-31 from seat-identity draft)

- **One seat = one identity = one token slot.** A second copy of a token
  anywhere is drift and is removed without reading it.
- Agents never mint their own tokens; provisioning, rotation, and scope changes
  are operator authority. Credential refusal is _correct behavior_ — the fix is
  the seat's identity, never another seat's or a shared credential.
- Fail-closed everywhere: an empty/unreadable slot is a designed state reported
  at launch; the credential helper refuses, records, notifies — never falls
  back to a shared or owner credential.
- Git identity resolution order: explicit environment identity → configured
  identity → git's own answer. Identity is named on every invocation and never
  persisted inside a shared clone/worktree config (silent attribution rewrite).
  Commit author must identify the seat that did the work.
- Tokens are compared by digest, never by value; scopes are verified from the
  authority's own report, never transcription.

## E2 inputs (triage 2026-08-31; see [[GOV.2-docs-inventory]])

**Canonical ground truth**: `fleet/reference/agent-mutations.md`,
`fleet/reference/lifecycle-transitions.md` (`enabled`/`desired_state` authority),
`fleet/how-to/create-update-delete-agent.md`, `guides/fleet-local-canary.md`.
**Pending pulls**: brain `docs/guides/proposed/operations/seat-identity.md`
(credential-resolution mechanics under the OD-48 instance contract).

## Role-binding step-up ruling (Q-S2, Jason 2026-09-01)

Confirming a role-binding change requires fresh principal re-authentication no
older than 10 minutes — the same step-up bar the S2 identity-lifecycle
contract sets for account linking. An active session alone is insufficient;
this closes the stolen-session → privilege-misdirection path through the seat
surface.

## Seat record consolidation ruling (Q-D1, Jason 2026-09-01)

`launch.env` consolidates into `profile.json`: one seat record. Verified:
`mosaic-core/lib/loader.ts seatRole()` reads only the `role` key from a
generically-parsed record, so widened files are tolerated by construction.