ReleaseBytes
python Pydantic AI Releases · · 2.26.0

pydantic-ai v2.26.0: Run cancellation and tool deferral

sdkaiengineerpython-agentic
feature patch

Pydantic-ai v2.26.0 introduces first-party run cancellation capabilities, allowing agents to be stopped mid-execution via `AgentRun.cancel()` or `RunContext.cancel()`. The release also enhances tool management by supporting deferred function tools, improving how tools are revealed and managed throughout agent interactions. These features, along with several bug fixes and provider updates, are available now and benefit developers building complex agentic workflows.

  • →Map streamed OpenRouter reasoning details by their index by @VictorPeralta in https://github.com/pydantic/pydantic-ai/pull/7214
Features (5) ›

  • Support hiding function tools until revealed — via tool search, load_capability, or ToolReturn.tools — using each provider's native deferral/addition channel by @DouweM in https://github.com/pydantic/pydantic-ai/pull/7104

  • Add first-party run cancellation: AgentRun.cancel(), RunContext.cancel(), RunCancelled by @DouweM in https://github.com/pydantic/pydantic-ai/pull/6497

  • Add Model.resolve_prompt_cache_retention() to resolve effective prompt-cache retention from model settings by @DouweM in https://github.com/pydantic/pydantic-ai/pull/7254

  • Promote run_stream_events() iterator to public AgentRunEvents handle with cancel() and run-state access by @DouweM in https://github.com/pydantic/pydantic-ai/pull/6498

  • Cover and document DeepSeek V4 Flash via OpenAIResponsesModel + DeepSeekProvider by @dsfaccini in https://github.com/pydantic/pydantic-ai/pull/7202

Fixes (7) ›

  • Forward model_id through WrapperModel and resolve it against the active model in TemporalModel by @dsfaccini in https://github.com/pydantic/pydantic-ai/pull/7181

  • Map streamed OpenRouter reasoning details by their index by @VictorPeralta in https://github.com/pydantic/pydantic-ai/pull/7214

  • Gate OpenRouter off native mid-conversation system messages with supports_inline_system_prompts=False by @DouweM in https://github.com/pydantic/pydantic-ai/pull/7253

  • Restore the released legacy profile-key shim and fix two reveal-state edges (is_tool_available, TestModel native additions) by @DouweM in https://github.com/pydantic/pydantic-ai/pull/7260

  • Keep deferred tools searchable after discovery and reset reveal state at CompactionPart boundaries by @DouweM in https://github.com/pydantic/pydantic-ai/pull/7225

  • Forward events from UIEventStream callbacks that return an async iterator without being an async generator function by @DouweM in https://github.com/pydantic/pydantic-ai/pull/7256

  • Send only the compacted window: drop history before the latest same-provider CompactionPart by @DouweM in https://github.com/pydantic/pydantic-ai/pull/7228

Read the original announcement →

https://github.com/pydantic/pydantic-ai/releases/tag/v2.26.0

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