Starts a new agent run and streams progress and output over Server Sent Events (text/event-stream).

The first event includes the runId as task.id. Store this value so you can retrieve the run later with Get Agent Run or reconnect using Resume Agent Run Stream.

The stream includes status updates and artifact content as the agent runs. The first artifact represents the primary response and may contain text and structured data. A final status update indicates that the run has reached a terminal state.

This endpoint is available only for agents that support STREAMING in capabilities.executionModes. The request uses the same message format and inputSchema validation as Start Agent Run. Customer-defined Agent Teams on the platform do not currently support streaming. Agents that do not support streaming return 400 STREAMING_NOT_SUPPORTED.