Pydantic AI Updates: May 22, 2026

1. Pydantic AI v1.101.0 adds a pending message queue, MCP background tasks, and model-agnostic XSearch

Pydantic AI. v1.101.0 introduces a pending message queue exposed through ctx.enqueue and agent_run.enqueue, giving callers a way to push additional messages into an in-flight run rather than waiting for the next turn boundary. The release also implements MCP background tasks support, makes the XSearch capability model-agnostic by falling back to a subagent when the underlying provider lacks native support, and threads top_k model settings through the Google, Anthropic, and Cohere integrations. Bug fixes target AnthropicModel dropping code execution tool results across multi-turn conversations, thinking being silently discarded for Claude Sonnet and Opus 4.6 on Bedrock, and BaseModel tool arguments being dropped when the model used the default extra='ignore' configuration. Source