Pydantic AI Updates: September 18, 2026

1. Pydantic AI 2.45.0 Added a TypeSafeModel for Jev and Tightened Durable Runs

Pydantic AI shipped 2.45.0 with TypeSafeModel, a provider class for TypeSafe’s Jev, the decision model that returns typed Choice, Score, and Boolean answers instead of generated text. The release also cut per-unit overhead in durable execution: a DynamicToolset now resolves once per durable run rather than inside every durable unit, and an MCP server session is held once per run rather than once per unit. Smaller fixes pass xhigh effort through on Bedrock where the model profile supports it, allow gpt-5.6-sol, gpt-5.6-luna, and gpt-5.6-terra on Bedrock Converse, preserve tool history in MCPSamplingModel, and stop pydantic_ai.mcp importing legacy httpx, which a FastMCP 4 install does not ship. Source