Pydantic AI v2.55.0 (2026-10-09)

Pydantic AI releases published Pydantic AI v2.55.0 (2026-10-09). This automated release-watch entry was generated from the project's official GitHub release feed and is kept separate from human-reviewed editorial analysis. Release notes: What's Changed ⚠️ Compatibility Notes Require Python 3.11 or newer in every package; Python 3.10 installs resolve to 2.54.0 and earlier by @Kludex in https://github.com/pydantic/pydantic-ai/pull/9526 Record the tool requests of ExaSearch , YouSearch , LocalStack and other harness capabilities under durable execution by @DouweM in https://github.com/pydantic/pydantic-ai/pull/9705 Bound retained realtime audio like retained images with retain audio max seconds by @DouweM in https://github.com/pydantic/pydantic-ai/pull/9702 Prefix LogfireMCP tool names with logfire by @mpfaffenberger in https://github.com/pydantic/pydantic-ai/pull/9868 Serialize FileUrl.media type as null for extensionless URLs instead of raising by @pydanty (https://github.com/apps/pydanty) in https://github.com/pydantic/pydantic-ai/pull/8405 Take realtime history, usage, and reply waits from the session core on OpenAI,…

• Review the official Pydantic AI releases release notes before upgrading.
• Check compatibility, migration, and security notes against your current agent stack.
• Run focused regression tests before production rollout.