turns
Create Turn
Stream one Turn, opening claim and preparation inside the SSE generator.
post/api/sessions/{session_id}/turns
Path parameters
session_idstring uuid required
Headers
Idempotency-Keystring required
Request body
Response
AI SDK UI v1 UIMessage SSE stream. It opens immediately with a transient data-status prelude (phase=preparation) that repeats every runtime heartbeat until the Turn is claimed and prepared. Claim or preparation failures no longer change the HTTP status: they project closed error + finish chunks inside the stream, and cancellation projects one abort chunk.