3.1.0 (2026-08-14)

Features

• api: add WebSocket stream IDs (#3612) (d9029e3)
• api: add workload identity access token issued event (#3601) (df274d4)
• api: deprecate Sora video APIs (#3610) (721cb1c)
• api: Ultrafast tier, structured MCP and websocket errors, separate websocket events (#3617) (f38355e)

Chores

• remove Stainless attribution and infrastructure (#3599) (a1eeab5)

3.0.0 (2026-08-12)

⚠ BREAKING CHANGES

• api: HTTPX2 is now the default HTTP client, and httpx is no longer installed automatically. Applications using custom HTTPX clients, transports, or configuration objects must migrate to their HTTPX2 equivalents or use the temporary, runtime-only legacy HTTPX escape hatch. See the HTTPX2 migration guide.

Features

• api: migrate to HTTPX2 (#3594)

2.54.0 (2026-08-11)

Features

• api: Add new Responses model identifiers (#3595) (0652787)

Bug Fixes

• api: clarify audio upload metadata requirements (#3596) (28888f9)

Chores

• api: Update generated-file header attribution to Castiron (#3583) (ea17fda)

2.53.0 (2026-08-03)

Features

• api: Add gpt-5.5 and tool name/namespace to Responses types (#3569) (dd1202d)

Bug Fixes

• ci: avoid NumPy source builds and duplicate HTTPX coverage (#3573) (b58332f)

2.52.1 (2026-07-31)

Full Changelog: v2.52.0...v2.52.1

Chores

• ci: pin setup-uv v5 to its underlying commit (#3560) (cbdc98b)

2.52.0 (2026-07-31)

Full Changelog: v2.51.0...v2.52.0

Features

• api: content provenance checks (1d6c118)

Bug Fixes

• client: honor Retry-After delays up to two minutes (#3555) (7fa7946)

Documentation

• add API-key mTLS HTTP client recipes (#3552) (7a3d5e4)

2.51.0 (2026-07-30)

Full Changelog: v2.50.0...v2.51.0

Features

• api: fast tier (8808ed2)

Bug Fixes

• api: add fast tier to helper methods (6064126)

2.50.0 (2026-07-28)

Full Changelog: v2.49.0...v2.50.0

Features

• api: transcription model updates (fd57393)

Bug Fixes

• audio: restore transcription keyword overload (713a262)

2.49.0 (2026-07-27)

Full Changelog: v2.48.0...v2.49.0

Features

• require Python 3.10 and automate version reviews (#3537) (d4c151d)

2.48.0 (2026-07-23)

Full Changelog: v2.47.0...v2.48.0

Features

• api: accept None for prompt_cache_key/safety_identifier (36820e6)
• api: add support for spend_limit admin apis (1ff13af)