session.subscribe()

session.subscribe() gives you a session-level future event sequence through a callback.

const unsubscribe = session.subscribe((event) => {
  console.log(event);
});

Example

const session = await agent.session("repo-analysis");

const unsubscribe = session.subscribe((event) => {
  if (event.type === "text-delta") {
    process.stdout.write(event.text);
  }
});

const turn = await session.prompt({
  query: "Analyze this repository",
});

await session.prompt({
  query: "Only look at the VisibleBase path",
});

await turn.finished;

unsubscribe();

Event model

The local Session actor currently emits a minimal turn-oriented event set:

• turn-start
• text-delta
• reasoning-delta
• tool-call
• tool-result
• turn-finish

subscribe() does not replay history.

If you need past messages, use session.history().

Why callback-based

For embedded runtimes, desktop apps, service hosts, and remote HTTP clients, a session-level callback subscription is usually simpler than creating a separate per-prompt output object.