Changelog

2026-04-24

Added WebSocket transport for /v1/responses. Clients start turns with response.create, and servers reuse the same semantic streaming events as HTTP streaming.
Defined sequential WebSocket turns, previous_response_id continuation, connection-local state for store=false, recovery after disconnects, the 60-minute connection limit, and structured error events.
Added POST /v1/responses/compact and its request and response schemas, including the rules for continuing over WebSockets after compaction.
Added the optional assistant-message phase field with commentary and final_answer values.
Made logprobs optional in output-text objects and streaming events.
Corrected the createResponse operation ID and completed the ResponseResource example.

Launched Open Responses as an open, multi-provider specification with a shared schema, semantic streaming events, item lifecycle rules, and extensible tooling.