Resuming a subgraph with breakpoints in Langgraph

[jleonelion]

I am trying to encapsulate two existing graphs to assemble a larger workflow. At this point, I am defining the nodes in the parent graph passing output of StateGraph.compile() from each of the subgraphs; then I have edges between those two nodes to define the overall parent graph:

stateDiagram-v2
    [*] --> subgraph1
    subgraph1 --> subgraph2
    subgraph2 --> [*]

Loading

Problem is subgraph1 has breakpoints (to solicit human input) and I can't figure out how to resume execution of the subgraph after the input is received. When I am directly testing subgraph1, I can directly update state with something like the following:

graph.update_state(
    thread_config,
    {"input": "hi"},
)

but in this case, subgraph1.get_state(thread) does not seem to return a valid state (ex. .next is empty {})

Is there any example handling subgraphs with dynamic breakpoints?

[jleonelion]

I will move this to the langgraph project

[anmol-aidora]

Hey, I am facing the same issue. I didn't see you raising it on the langgraph repo discussion. Did you find a way to figure this out? Let's discuss more about this

[jleonelion]

@anmol-aidora I came across reference to this article and it answered my questions.
https://langchain-ai.github.io/langgraph/how-tos/subgraphs-manage-state/#resuming-from-specific-subgraph-node