Split content into list and run sub graph on each element (like RunnableEach in LCEL)

[arthurGrigo]

I want to split a list of strings and run a subgraph on each list element (maybe even multiple subgraphs in parallel). I know how to do it with LCEL but how could I do it in langgraph?

[hinthornw]

We're planning to expand the API to make it easier to send custom instructions to a node or do map-reduce type work

[SoulEvill]

Following on this. One of my use case is to be able to run multiple llm in parallel then get to a decision point to decide which result to take. I believe currently it is not supported yet and would love to have this map-reduce type flow set up.

[hinthornw]

map-reduce is possible, it's just not the kindest syntax right now. We do variants of branching and collapsing in the LATS example for instance.

If you just want to run multiple LLMs in parallel on the same input, you could directly branch (https://langchain-ai.github.io/langgraph/how-tos/branching/) and then reduce after they've all returned their judgements. This would be a simple form of ensembling.

If you want to subdivide work, you can add separate keys in the state for different nodes.

[SoulEvill]

Thanks really helpful thanks for point to this document, this serve exactly my needs.