Setting the file. One moment.
Subchapter 1.10
references/observability.mdMarkdown1 KBView on GitHub
Fetch https://developers.cloudflare.com/agents/api-reference/observability/ (opens in a new tab) for complete documentation.
Agents emit structured events via Node.js diagnostics_channel. Subscribe in development or forward via Tail Workers in production.
import { subscribe } from "agents/observability";
subscribe("agents:rpc", (event) => {
console.log(`RPC call: ${event.payload.method}`);
});
subscribe("agents:state", (event) => {
console.log(`State change on ${event.agent}`);
});| Channel | Events |
|---|---|
agents:state | State changes |
agents:rpc | @callable invocations |
agents:message | WebSocket messages |
agents:schedule | Schedule triggers |
agents:lifecycle | Agent start, connect, disconnect |
agents:workflow | Workflow progress, completion, errors |
agents:mcp | MCP server connections, tool calls |
agents:email | Email received |
export class MyAgent extends Agent<Env, State> {
observability = undefined; // disable for this agent
}In production, events appear as diagnosticsChannelEvents on the Tail Worker event object. Attach a Tail Worker to your agent’s Worker to forward events to your observability platform.