Streaming Events

agent.query() returns an async generator of SDK messages.

for await (const message of agent.query("What is 2+2?")) {
  switch (message.type) {
    case "system":
      console.log("session", message.session_id);
      break;
    case "stream_event":
      console.log("raw stream event", message.event);
      break;
    case "assistant":
      console.log("assistant message", message.message);
      break;
    case "user":
      console.log("tool result", message.tool_use_result);
      break;
    case "result":
      console.log("final", message.result);
      break;
  }
}

Message types

Type	Description
system	Session initialization metadata.
stream_event	Raw provider stream events, emitted when streaming is enabled.
assistant	Assistant message after model assembly.
user	Tool result message sent back to the model.
result	Final success, API error, abort, or max-turn result.