When to use config['configurable'] vs. context in graph nodes?

OSS Product Help LangGraph
1

Hi all,

I see a previous post around this topic but I find the replies confusing.

I am building a simulation with multiple rounds where agents need to solve jobs each round. I am using LangGraph for the simulation loop.
In each round a list of different jobs are generated. I want to do this in the very first node of my graph (a start_round node). At the end of every round I will loop back to this node and generate new jobs.

For generating the jobs I want to pass an instance of my JobGenerator class such that the node can use the methods provided by this class.

Should I pass the instance of the class via the config or context argument and why? Is what I am trying to achieve even possible?

Another possibility would be to add the instance to the state, but fields in the state need to be serializable right?

Any guidance is appreciated - I am happy to provide more information if needed.

2

sounds like something that belongs in runtime context, bc you don’t want to serialize it
you can think of runtime context as injected read-only deps

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3

Okay great, thanks for the reply! :smile:

What is the use case for config then if I may ask?

4

config[“configurable”] is the old untyped version of runtime.context :slight_smile:

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5

You are a lifesaver. Thank you! :folded_hands:

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6

it also has other internal config information (like thread id, etc), but we’ll eventually move to properly typing those as well

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