Add An Attached Stream

Outcome

You can register an attached stream handler and expose live output through the Cloudflare DO facade.

Prerequisites

• Attached streams
• Durable truth
• Runtime package
• Cloudflare DO backend

Steps

1. Define an AttachedStreamHandler in app code.
2. Choose mode: "bidi" for WebSocket or mode: "output_only" for SSE.
3. Choose cancellation and onDetach explicitly.
4. Yield output or progress frames from run.
5. Yield one terminal frame and write durable facts in commitTerminal.
6. Register the handler with defineAgentDO({ streams: [handler] }).

References

• Attached stream API
• Runtime API