Langgraph Deep Agents does not populate user_id in the metadata

[Nymbayar]

Describe your question

I am using Langgraph Deep Agents. Since I've been starting my Agent via Langgraph CLI, then it does not populate user_id in the agent metadata to the langfuse.

I added langfuse user id to the agent config like this:

    config_dict['metadata'] = {
        'langfuse_user_id': user_id,
        'langfuse_session_id': product_id,
    }

But showing no user id in the Langfuse Platform.

Langfuse Cloud or Self-Hosted?

Langfuse Cloud

If Self-Hosted

No response

If Langfuse Cloud

No response

SDK and integration versions

3.10.1

Pre-Submission Checklist

• I have checked for existing issues/discussions and consulted Langfuse AI.

[inkeep-ai-assistant[bot]]

Based on the available documentation, there are two recommended approaches to properly set user_id and session_id in LangGraph with Langfuse SDK v3:

Option 1: Use propagate_attributes() with the CallbackHandler

This is the recommended approach for SDK v3. You need to use propagate_attributes() to ensure the user and session IDs are properly propagated to all child observations(1):

from langfuse import get_client, propagate_attributes
from langfuse.langchain import CallbackHandler

langfuse = get_client()
handler = CallbackHandler()

with langfuse.start_as_current_observation(as_type="span", name="langchain-call"):
    # Propagate user_id to all observations
    with propagate_attributes(user_id="user_12345"):
        # Pass handler to the chain invocation
        chain.invoke(
            {"animal": "dog"},
            config={"callbacks": [handler]},
        )

(1)

Option 2: Via metadata in the config

You can also pass these as metadata in the workflow invocation config(2):

result = workflow.invoke(
    initial_state,
    config={
        "callbacks": [langfuse_handler],
        "metadata": {
            "langfuse_session_id": "your-session-id",
            "langfuse_user_id": "your-user-id",
        },
    },
)

(2)

However, there's a known issue with SDK v3 where metadata like session_id and user_id is only picked up if the execution is treated as a chain(3). The workaround is to use RunnablePassthrough at the start of your chain to force proper metadata propagation(3).

Since you're using LangGraph Deep Agents via the LangGraph CLI, you may need to ensure your configuration follows one of these patterns to properly propagate the user and session IDs to Langfuse.

📚 Sources:

1. LangChain & LangGraph Integration
2. Having user_id and session_id with Langgraph integration
3. bug: session_id and user_id not being passed in new sdk through callback in LangGraph

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[jannikmaierhoefer]

Hi @Nymbayar, please use propagate_attributes as mentioned by inkeep. Let me know if this works for you.