<Async Postgres checkpointer - Don't wish to compile graph everytime>

[saurabhlalsaxena]

Is there a way to not compile the graph every time we are trying to call a graph. Context: The Graph is part of a LangServe Endpoint.

[vbarda]

@saurabhlalsaxena you don't need to compile the graph every time -- see this discussion for an example of how to do it using FastAPI lifespan #894 (reply in thread). but even if you did compile it every time, it is very fast in practice! let me know if this helps

[saurabhlalsaxena]

@vbarda I have read the post but find it super confusing. I have a complex API with multiple endpoints using APIRouter(), lifespan feels a bit less elegant as a solution. Also all the examples in the thread still compile the graph each time. My LangGraph is quite complex with nested graphs and compiling the graph does take some time as each graph needs to be compiled. Hence was looking for a solution that can help me compile the graph once and then use it. We want to be able to use ainvoke as it is a non blocking operation allowing resources to be utilised more efficiently. Also we are using checkpointer for streaming, which is a safer streaming channel and doesn't lead to Generator Exit with long running Graphs.

[saurabhlalsaxena]

@vbarda you can check out our product - www.trusttyreporter.com
Demo video : https://youtu.be/qdGPwYthwBg?si=mPvospIxQb0y-1GH

We also have an open source Perplexity Clone which is based on the Trustty Reporter architecture using LangGraph and LangServe:
https://github.com/saurabhlalsaxena/Perplexity-Clone-LangGraph

Also attached the frontend for the Perplexity Clone.

[saurabhlalsaxena]

@vbarda I tried using lifespan, but it seems that the add_routes() function is not injecting the request, I keep getting the error:
TypeError: custom_chain() missing 1 required positional argument: 'request'