Pydantic AI Updates: April 22, 2026

1. Pydantic AI 1.85.0 Adds Online Evaluation via OpenTelemetry Events

Pydantic. Pydantic AI 1.85.0 lands a single headline feature: online evaluation implemented on top of OpenTelemetry events, letting teams wire agent runs to evaluation pipelines without standing up a separate pipeline or rerunning traces offline. Source

2. Pydantic AI 1.85.1 Cleans Up Retry Messages and Vercel AI Deferred-Tool Handling

Pydantic. The 1.85.1 patch ships two user-visible fixes: retry messages no longer echo input data into the error payload, and the Vercel AI integration now detects deferred tool-approval status when dumping messages, which matters for agents that route through Vercel’s gateway for human-in-the-loop tool approvals. Source