pydantic/pydantic-ai v1.77.0

v1.77.0 (2026-04-02)

on GitHub

What's Changed

🚀 Features

• feat: add local WebFetch tool and have WebFetch capability use it when provider lacks builtin support by @DEENUU1 in #4906
• Add defer_loading to tools and toolsets to enable tool search by @dsfaccini in #4090
• Add ThreadExecutor capability and Agent.using_thread_executor() by @DouweM in #4942
• feat: smart instruction caching — automatically insert Anthropic/Bedrock cache boundary at static/dynamic split by @Alex-Resch in #4865
• Support server_message_id in VercelAIEventStream by @dsfaccini in #4579

🐛 Bug Fixes

• fix: run output validators for image outputs by @dsfaccini in #4938
• Wrap streaming SDK errors in ModelHTTPError/ModelAPIError by @dsfaccini in #4889

New Contributors

• @Alex-Resch made their first contribution in #4865

Full Changelog: v1.76.0...v1.77.0