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.

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.