Major updates today: LangChain v0.3 / pydantic v2, full uv support, astream_events

[JoshuaC215]

A heads up that I just merged some big changes to the repo this evening:

• Switched from CallbackHandler to astream_events approach for streaming (Switch to astream_events to support token-level streaming with Gemini #32) which should add support for more models (thanks @peterkeppert)
• Upgrade to Langchain v0.3 which also unlocks Pydantic v2 and latest FastAPI (thanks @7sunstudio for also validating)
• Fully convert to uv usage and uv.lock file for frozen dependency support (thanks @3x10RaiseTo8 for original ask and contributions)

These have been on the agenda for the past couple of weeks. Some of the next improvements in mind:

• More test coverage
• Support for running multiple agents in the service at once

Would love to hear any feedback, how the latest changes are working for you, and any other ideas. Also welcoming more contributions - feel free to open an issue to discuss first for bigger changes.

Thanks!