# Pi stable baseline

## Status

Release candidate for Pi-to-Pi communication over AMQ filesystem transport.

This is a stable Pi baseline, not completion of multi-harness interoperability.

## Scope

Supported:

- two or more Pi sessions;
- shared AMQ filesystem root;
- notify-pull envelope delivery;
- explicit read/reply/resolve IDs;
- shared owner arbitration;
- reload heartbeat and presence TTL;
- bounded nested active-work stack across continuations, urgent scheduling, read, and takeover;
- stale-work diagnostics and explicit recovery policy;
- isolated natural sequential collaboration acceptance.

## Verification

- Automated suite: **172/172 passing**.
- TypeScript: `npx tsc --noEmit` passing.
- Natural exact run 1: `e2e-natural-peer-20260803-211328-8569` passing.
- Natural exact run 2: `e2e-natural-peer-20260803-211537-17786` passing.
- Both runs validated sender, kind, priority, isolated root, and zero matching residue.
- Live reload verification: `ab` and `bp` presence active with advancing heartbeats.
- Exact multi-peer presence E2E: `bip↔bop`, secondary `bip` detach, then `pib→bop`; final status exactly `[bop] ↔ bip, pib` and AMQ roster exactly `bip,bop,pib`.

## Existing-root behavior

Use `npm run e2e:natural:existing` only as stale-history diagnostics. Existing unresolved work is never silently cleared. Status identifies active work in `new/`, `cur/`, or missing state. Operator must resume, explicitly resolve/abandon, or quarantine.

## Known limitations

- Urgent messages do not provide hard cancellation of an active provider turn.
- Urgent preemption/queue semantics remain post-baseline work.
- Reply operation journal/idempotency across crash boundaries remains post-baseline work.
- OpenCode and Codex adapters are intentionally deferred until core architecture and lifecycle semantics mature.
- Shared filesystem mailbox has no authentication against malicious writers.

## Release rule

Do not describe this baseline as multi-harness stable. Use exact wording:

> Pi + AMQ filesystem stable baseline; harness-neutral migration in progress.