Inspector protocol

Wire-level and integration rules for the RivetKit actor inspector (WebSocket + HTTP).

Two transports, one source of truth

• The HTTP inspector endpoints at rivetkit-typescript/packages/rivetkit/src/actor/router.ts mirror the WebSocket inspector at rivetkit-typescript/packages/rivetkit/src/inspector/. The HTTP API exists for agent-based debugging.
• When updating the WebSocket inspector, also update the HTTP endpoints.
• When adding or modifying inspector endpoints, also update:
  • Relevant tests in rivetkit-typescript/packages/rivetkit/tests/ to cover all inspector HTTP endpoints.
  • Docs in website/src/metadata/skill-base-rivetkit.md and website/src/content/docs/actors/debugging.mdx.

Version negotiation

• Wire-version negotiation belongs in rivetkit-core via ActorContext.decodeInspectorRequest(...) / encodeInspectorResponse(...). Do not reintroduce TS-side inspector-versioned.ts converters.
• Downgrades for unsupported features become explicit Error messages with inspector.*_dropped codes. Do not silently strip payloads.

WebSocket transport

• Outbound frames stay at wire format v4.
• Inbound request frames accept v1 through v4.
• Live updates fan out through InspectorSignal subscriptions.
• Snapshots read live queue state instead of trusting pre-attach counters.

Queue-size reads

• Native inspector queue-size reads come from ctx.inspectorSnapshot().queueSize in rivetkit-core. Do not use TS-side caches or hardcoded fallback values.

Workflow inspector support

• Workflow inspector support is inferred from mailbox replies — actor.dropped_reply means unsupported. Do not resurrect Inspector callback flags or unconditional workflow-enabled booleans.