pydantic/pydantic-ai v2.51.0 on GitHub

What's Changed

Match dated gemini-3.8-live ids, reject google_affective_dialog on Gemini 3.1 Flash Live and 3.8 Live at connect, and raise RealtimeError for Gemini Live close codes by @DouweM in #8761
Raise a UserError for a realtime tool_choice that forces a tool call on OpenAI, Azure OpenAI, and xAI by @DouweM in #8755

Add OpenAI GPT-Live support with OpenAILiveModel by @DouweM in #8390
Expose context_window_used on realtime sessions, from GPT-Live's reported ratio or response usage by @DouweM in #8803

Reduce RunContext copying overhead in capability hooks by @Kludex in #8775
Keep provider_details on OpenAI Realtime tool-call responses and the response id on replies cut off by a drop or close() by @DouweM in #8762
Buffer text deltas in CompletedStreamedResponse replay by @Kludex in #8799
Resend a recent image with a typed Gemini Live turn, which doesn't see video frames by @DouweM in #8756
Cache the agent graph instead of rebuilding it on every Agent.run() by @Kludex in #8658
Stop spawning a task group when a toolset or capability fan-out has a single child by @Kludex in #8774

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