I've been building an integration [1] with Pydantic AI and the experience has been great. Questions usually get answered within a few hours, and the team is super responsive and supportive for external contributors. The public API is easy to extend for new functionality (in my case, durable agents).
Its agent model feels similar to OpenAI's: flexible and dynamic without needing to predefine a DAG. Execution is automatically traced and can be exported to Logfire, which makes observability pretty smooth too. Looking forward to their upcoming V1 release.
Shameless plug: I've been working on a DBOS [2] integration into Pydantic-AI as a lightweight durable agent solution.