Pydantic AI Updates: August 27, 2026

1. Pydantic AI v2.35.0 Refines Capability APIs and Tool Descriptions

Pydantic AI. Pydantic AI released v2.35.0, which deprecates the RunContext capability_loaded and available_capability_ids members in favor of capability_active and active_capability_ids. The release also reduces the default Temporal metric export frequency, makes the inclusive integer maximum reachable in TestModel, and fixes tool descriptions so explicit empty values are preserved rather than falling back to function docstrings. Source

2. Pydantic AI v2.35.1 Fixes Bedrock Guardrail Traces and Temporal Cancellation

Pydantic AI. Pydantic AI followed with v2.35.1, a maintenance release that carries the Bedrock guardrail trace through ModelResponse.provider_details so the information surfaces in responses. It also honors the provider_factory parameter when cancelling Temporal responses and caps the dbos dependency below version 2.31.0 to avoid import errors tied to missing OpenTelemetry logging instrumentation. Source