Pydantic AI Updates: July 23, 2026

1. Pydantic AI v2.16.0 Adds ToolFailed, Run IDs, And Google Model Armor

Pydantic AI. Pydantic AI released v2.16.0, introducing a ToolFailed mechanism for surfacing model-visible failures without triggering automatic retries and an optional run_id parameter across agent runs, durable wrappers, and UI adapters. The release adds a mistral_prompt_cache_key setting and passes parallel_tool_calls to the Mistral SDK, hoists openai_moderation to OpenAIChatModelSettings, and adds Google Model Armor support through GoogleModelSettings along with the gemini-3.6-flash and gemini-3.5-flash-lite models. It also standardizes ctx.enqueue() error handling across the Temporal, DBOS, and Prefect durable units and corrects tool retry counts across skipped steps. Source