# Run Control Contract

Control is the lightweight high-priority channel between run and platform.

## Implemented Routes

- `POST /api/v1/run/control/hello`: registers run metadata and receives a platform-issued session token.
- `POST /api/v1/run/control/heartbeat`: reports status, capacity, and capability fingerprint using the active session token.

## Payloads

- `RunHelloRequest`: registration token, run ID, display name, version, status, platform, capability summary, and capacity summary.
- `RunHelloResponse`: session token, server time, polling hints, and feature flags.
- `RunHeartbeatRequest`: session token, version, status, capacity, and current capability fingerprint.
- `RunHeartbeatResponse`: accepted status, next heartbeat interval, and optional capability refresh request.
- `RunCapabilityReport`: capability names and compact fingerprint metadata.
- `RunCapacityReport`: max jobs, active jobs, queued jobs, and local resource summary.

## Rules

- Control payloads must be small.
- Control must not carry logs, artifact chunks, or long job result bodies.
- Control must have priority over job execution, log upload, and artifact transfer.
- Heartbeat capacity summaries must remain metadata-only and must not mention or carry heavy channel payloads.

## Deferred Channels

Durable log ingest, artifact chunk transfer, and the optional game client bridge remain separate channels. The job channel is separate from control and uses `/api/v1/run/jobs/*` routes.