runtime: process exits on any failed agent fetch (UND_ERR_SOCKET / UND_ERR_BODY_TIMEOUT)

[nanaknihal]

Summary

Any failure of the runtime's HTTP request to the Python agent — a dropped socket, a slow turn, an agent restart — raises an unhandled rejection inside undici and kills the whole runtime process (server.ts). The Slack/Teams channel session dies with it, and every message until an operator restarts the process is silently lost.

Observed three times in one evening of local testing, two distinct signatures:

1. Agent restarted mid-request (also reproduced by killing the agent during a turn):

Agent execution failed: TypeError: terminated
    at Fetch.onAborted (node:internal/deps/undici/undici:11124:53)
  [cause]: SocketError: other side closed
    code: 'UND_ERR_SOCKET'

2. Agent turn exceeded undici's default 300s body timeout (a long tool-heavy turn with no stream activity):

node:internal/process/promises:394
    triggerUncaughtException(err, true /* fromPromise */);
TypeError: terminated
    code: 'UND_ERR_BODY_TIMEOUT'

Both escape as uncaught exceptions / unhandled rejections, so Node terminates the process.

Why it matters

The runtime is the long-lived member of the pair — it holds the Intelligence channel session. A transient agent-side hiccup (deploy, OOM, slow model call) shouldn't take down message delivery for the whole workspace. There's also a secondary effect: when the crash lands mid-turn, the agent's LangGraph state can be left with a dangling tool call, and the next turn on that thread fails with the Responses API's No tool output found for function call ….

Suggested fix

• Wrap the agent fetch (and its stream consumption) so failures are caught, logged, and surfaced as a failed run — not an uncaught exception. A process.on('unhandledRejection') backstop that logs instead of exiting would also stop the bleeding.
• Consider raising or configuring undici's bodyTimeout for the agent request (long agentic turns with sparse stream output can legitimately exceed 300s), or send periodic keep-alive events from the agent.

Happy to help test a fix — local repro is reliable: start a turn, then either kill the agent process or give it a tool that sleeps past 300s.

Environment: OpenTag main, Node v22.14.0, runtime via pnpm runtime / tsx server.ts, agent via uvicorn locally.