Pydantic AI Updates: May 1, 2026

1. Pydantic AI v1.89.0 Adds conversation_id, Dynamic Capabilities, and builtin_tools Override

Pydantic AI. Pydantic AI v1.89.0 introduces a conversation_id field for correlating multiple agent runs across a single logical conversation, making it easier to thread together traces, evaluations, and persisted history when an agent is invoked repeatedly. The release adds support for dynamic capabilities through callables in the capabilities list, so authors can compute which capabilities are active at run time based on context rather than declaring them statically. The agent.override helper now accepts builtin_tools, allowing tests and ad-hoc invocations to swap in or disable provider-side tools without rebuilding the agent. On the evaluation side, background evaluators now run on non-daemon threads so they finish their work before the process exits instead of being killed mid-flight, which previously caused dropped evaluator results in short-lived scripts. Source