# F4 — Orchestrator chat connector + Matrix (#616)

- **Issue:** #616 · **Branch:** `feat/f4-matrix-connector` (off main; independent of #615) · **Doctrine:** north-star #613.

## Phase 1 (this PR) — abstraction + scaffold

- `src/fleet/connectors/types.ts`: `OrchestratorConnector` (send/subscribe/health) + message/config types; thread-aware via optional `threadId`; `DEFAULT_CONNECTOR_KIND=tmux`.
- `src/fleet/connectors/registry.ts`: extensible factory registry; `resolveConnectorKind` (defaults tmux, back-compat); `createConnector` throws `ConnectorNotImplementedError` until Phase 2 registers factories.
- `roster.schema.json`: optional `connector` block (tmux|discord|matrix; matrix homeserver/user/room; secrets via env, never roster).
- Design doc `docs/fleet/f4-matrix-connector.md`: interface, config, Matrix CS-API mapping, Conduit-default infra, phasing.
- **No fleet.ts changes** → self-contained, zero conflict with stacked #615.

## Verification

- 7 connector tests green; tsc/eslint/prettier/sanitize clean; schema valid JSON.

## Phase 2+ (follow-ups, in the doc)

Matrix CS-API client (fetch send/sync/health) + factory; init/configure connector-selection UX + roster-parse wiring; systemd launch wiring; Conduit deploy guide; first-party Mosaic Discord (threads) as a connector.

## Phase 2a (feat/f4-matrix-client, stacked on #617) — Matrix CS-API client

- `src/fleet/connectors/matrix.ts`: `MatrixConnector implements OrchestratorConnector` over the Matrix
  client-server API (injectable fetch, no SDK). `send` → PUT m.room.message (thread-aware); `subscribe`
  → /sync long-poll loop using the pure `parseSyncResponse`; `health` → /versions + /whoami.
  `registerMatrixConnector(env)` registers the factory (token from MATRIX_ACCESS_TOKEN, never roster).
- Pure helpers `buildMessageBody` + `parseSyncResponse` make send/receive unit-testable.
- 13 Matrix tests + 7 registry = 20 connector tests green; tsc/eslint/prettier clean.
- Remaining Phase 2: init/configure connector-selection UX + roster-parse wiring (touches fleet.ts —
  after #615); systemd launch wiring; Conduit deploy guide.