PaperClipAI/packages/paperclip-runner/protocol

PRP v1/v2 Contract

The JSON Schema files in schemas/ are the language-neutral source of truth for Paperclip Runner Protocol versions 1 and 2. The fixtures in fixtures/ define accepted and rejected compatibility cases.

Compatibility

• protocolVersion, fixtureVersion, and event.schemaVersion are required.
• A consumer fails closed when a required version or schema discriminator is not supported.
• A v1 envelope can contain an unknown optional property when its schema marks that object as extensible.
• A consumer ignores an unknown optional property until a later contract gives it meaning.
• A required field, enum value, or typed structured-input field is not optional.
• Question and answer identifiers are stable across the provider boundary.
• Peers negotiate the highest mutually supported protocol version. Existing v1 runners remain compatible but cannot receive v2-only session-goal commands.

The unknown-optional-fields.json fixture must be accepted. The unsupported-required-version.json fixture must be rejected.

Session goals (v2)

PRP v2 adds a provider-neutral durable session-goal lifecycle. Every v2 capability snapshot includes sessionGoals, even when its availability is unsupported or policy_disabled. Paperclip sends controls only when the negotiated capability advertises the corresponding action.

Commands:

• session.goal.get
• session.goal.set for objective, status, and optional token budget changes
• session.goal.clear

Events:

• session.capabilities.updated
• session.goal.snapshot
• session.goal.updated
• session.goal.cleared

Goal state is separate from Paperclip's company/business goal hierarchy. The snapshot distinguishes the durable status from workingNow, because an active goal can be idle between autonomous turns. A runner emits the full capability and authoritative snapshot after every session open or resume. Missing v1 capability is unsupported; clients do not infer support from an adapter name.

Harness credential updates

auth.credentials.updated is a P0 runner event available in the v1, v2, and v3 event schemas. Its payload uses paperclip.auth.credentials.updated.v1 and contains only provider, bindingId, revision, and detection. No tokens, account identifiers, credential paths, or credential fingerprints are permitted.

An updated consumer opts in with observeCredentials: true in run.prepare, before session.open. The bundled runner transport opts in for fresh sessions; set its observeCredentials option to false to disable observation for a fresh session. Older hosts that omit the field receive no new event. Consumers must update their schemas before opting in: an event-enum addition is not an unknown optional property. Existing runner binaries ignore the optional flag and do not provide observation; absence of an event does not establish support.

The current Unix runner observes native Codex's managed CODEX_HOME/auth.json and the Codex/Grok ACPX session homes. It uses a non-recursive directory watch plus a one-second polling fallback, so atomic file replacement is handled. Grok's initial inline subscription credential is the baseline, allowing a refresh during launcher startup to be detected. A first valid credential file without a prior baseline establishes the baseline without claiming a refresh. Account identity changes also emit updates, even when token values stay the same, and establish the baseline for later refreshes on the new account. Hosts must evaluate the current credential through their private credential channel and account checks; the event does not authorize an account switch. Metadata-only changes, partial writes, and deletion do not emit updates. Unsupported harnesses and refreshes retained only in memory need their own observer or native-hook integration; adding this event does not make them observable.

bindingId: "harness-auth" identifies the selected harness authentication within the envelope's normalized session. Revisions increase for that binding and survive runner restarts and warm run attachments. The baseline fingerprint and pending event are persisted together in a private runner state file. Source retries retain the same event identity until the durable PRP outbox accepts it. Hosts should commit an idempotent reaction or durable work item through onCommittedEvent before returning and advancing the cumulative ACK. The bundled transport exposes onCredentialsUpdated(event) for this commit. It awaits the callback before ACK, including during warm idle, attachment, and provider cleanup. Callback failures leave delivery unacknowledged for retry; callbacks must therefore deduplicate by the original source event identity. When configured, credential updates bypass the turn notification queue. Paperclip commits them directly to the run log in a separate credential source namespace, preserving the original PRP envelope and avoiding collisions with the driver's normalized event sequence. A turn-only notification consumer cannot reliably handle idle or cleanup updates; use this callback instead.

detection: "credential_store" reports an observed credential change, not proof that an OAuth refresh succeeded. Multiple changes between observations can be coalesced; this is not an audit of every refresh exchange. The schema also allows native_hook for integrations with an explicit signal. Observation continues during warm idle and checks at turn terminal and close boundaries, including Grok's private refresh handoff after live-store cleanup. Retained runner observations enter the durable outbox before a suspend or shutdown command completes, without draining the provider backlog. A final check after provider cleanup also enters the outbox and waits for the host ACK. The runner retains its terminal recovery fence if that delivery fails.

The event authorizes no credential access or write on its own. A host that needs rotated token values must use a separately authorized handoff with its existing account-identity and freshness safeguards. The default Paperclip credential copy-back behavior remains in place.

Scope

The first provider descriptor and adapter fixture cover Codex only. The schemas for provider-neutral events and semantic receipts do not enable those actions. Discovery and authorization are separate contracts.

The conformance manifest records every source file and its SHA-256 digest. Run pnpm generate:protocol-manifest from this package after a source change. CI runs the same generator with --check to reject drift. This check also compiles the JSON Schemas and validates every replay, question, and cross-language conformance fixture against its declared schema.

The files in fixtures/replay/golden/ are deterministic reducer oracles. Each accepted replay fixture has a complete session snapshot and a compact parity summary. pnpm generate:replay-goldens updates them after an intentional reducer change; package build and CI fail when they drift.

The files in fixtures/local-runner/scripts/ drive the package-local fake harness. They cover successful, failed, interrupted, interactive, duplicate terminal, process-cleanup, and oversized-frame behavior without starting a production adapter.