# Tasks — W-FLEET (Fleet) Phase 2: Observability

> Workstream task file for the Fleet. Single-writer: Fleet workstream lead (orchestrator).
> Workers read but never modify. This is **not** the MVP rollup (`docs/TASKS.md`) — a
> rollup row is proposed to the MVP orchestrator, not written here.
>
> Mission: `mvp-20260312` · PRD: [docs/fleet/PRD.md](./PRD.md) · North star: [docs/fleet/north-star.md](./north-star.md)
> Status: `not-started` | `in-progress` | `done` | `blocked` | `failed`

| id | status | description | depends_on | agent | pr | notes |
|---|---|---|---|---|---|---|
| FLEET-OBS-000 | done | Plan: north-star + Phase-2 PRD + workstream scaffolding | — | lead | — | persisted 2026-06-20 on `feat/fleet-observability` |
| FLEET-OBS-001 | not-started | Heartbeat protocol v1 spec finalized in PRD + framework doc | FLEET-OBS-000 | lead | — | file-based `~/.config/mosaic/fleet/run/<agent>.hb` |
| FLEET-OBS-002 | not-started | Implement heartbeat responder in `dogfood-agent.py` | FLEET-OBS-001 | worker | — | emits ts/pid/status every 15s + on probe |
| FLEET-OBS-003 | not-started | `mosaic fleet ps` — join systemd+tmux+proc+idle+heartbeat; tenant+host tagged; drift + boot-enable flags; `--json` | FLEET-OBS-001 | worker | — | extend `packages/mosaic/src/commands/fleet.ts` |
| FLEET-OBS-004 | not-started | `mosaic agent watch <name>` — read-only join (no resize, no keystrokes) | FLEET-OBS-000 | worker | — | grouped session or `attach -r`; keep `attach` as takeover |
| FLEET-OBS-005 | not-started | `mosaic agent send --verify` — delivery/acceptance receipt | FLEET-OBS-000 | worker | — | non-zero on wedged/draft pane |
| FLEET-OBS-006 | not-started | CLI specs for ps/watch/send-verify (tenant+host shape, command construction) | FLEET-OBS-003,004,005 | worker | — | alongside impl (TDD where risk-bearing) |
| FLEET-OBS-007 | not-started | Framework doc: fleet observability guide + verbs | FLEET-OBS-003,004,005 | lead | — | `docs/guides/` or `framework/tools/.../README` |
| FLEET-OBS-008 | not-started | Independent review + dogfood verification on live fleet | FLEET-OBS-002..007 | reviewer | — | author ≠ reviewer; capture evidence in scratchpad |
| FLEET-OBS-009 | not-started | Open PR → green CI (queue guard) → squash-merge → close `fleet-observability-1` | FLEET-OBS-008 | lead | — | trunk merge; no direct push to main |

## Proposed MVP rollup row (for the MVP orchestrator — not written by this workstream)

```
| W-FLEET | in-progress | Fleet (agent-session execution layer) | Phase 2/5 | docs/fleet/TASKS.md | observability dogfooded on live stub fleet; control plane rides federation (W1) |
```