Authoring a chat agent

A chat.agent runs an entire conversation as one long-lived Trigger.dev task. It wakes when a message arrives, freezes when none do, and in-memory state survives page refreshes, deploys, idle gaps, and crashes. Your code is the loop you would write anyway: messages in, streamText out. There are no API routes. The frontend talks to the agent through a TriggerChatTransport, so history accumulates server-side and the client ships only the new message each turn.

Works with Vercel AI SDK v5, v6, or v7. On v7 also install @ai-sdk/otel so model calls are traced (the SDK registers it for you).

Setup

Three pieces: the agent task, two server actions, and the frontend transport.

1. Define the agent