pydantic/pydantic-ai v2.38.0 on GitHub

What's Changed

Add context_window to ModelProfile and context_window_used to RunContext by @adtyavrdhn in #4611
Add profile flag to reject streams without finish_reason by @jonashaag in #7096
Add gemini-3.8-flash model by @dsfaccini in #8021
Let application code and capabilities emit typed CustomEvents and CapabilityEvents into the run event stream and subscribe with @on_event by @DouweM in #6258
Add Claude Fable 5.1 (claude-fable-5-1) and Claude Mythos 5.1 (claude-mythos-5-1) support by @dsfaccini in #7989

Support CancellationToken in UI adapter run methods by @dsfaccini in #7743
Stop pytest tests/durable_exec/temporal from crashing when the suite's requirements are missing by @dsfaccini in #7898
Fix DeepSeek and Together forced tool_choice handling and support NativeOutput on DeepSeek's Responses API by @dsfaccini in #7450
Restore raw tool-call IDs when replaying Bedrock Mantle Responses history by @dsfaccini in #7962
Keep a run cancelled during its first tool call resumable by @DouweM in #7993
Fix CodeExecutionTool uploads never reaching a fresh Anthropic container on a multi-turn history by @dsfaccini in #7864
Prevent synthetic reasoning IDs from reaching OpenAI Responses by @dsfaccini in #8020
Emit REASONING_* events from ag-ui-protocol 0.1.11 instead of 0.1.13 by @dsfaccini in #7226
Accept the environment-key call pattern in GoogleProvider's overload by @dsfaccini in #8030
Fix XaiModel streamed text after a native tool call being merged into the ended pre-call part by @pydanty in #7925
Persist Anthropic stale thinking-block recovery across turns by @dsfaccini in #8037

Full Changelog: v2.37.0...v2.38.0