This guide shows how to add custom authentication to your LangGraph Platform application. This guide applies to both LangGraph Platform and self-hosted deployments. It does not apply to isolated usage of the LangGraph open source library in your own custom server.

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Add custom authentication to your deployment

To leverage custom authentication and access user-level metadata in your deployments, set up custom authentication to automatically populate the config["configurable"]["langgraph_auth_user"] object through a custom authentication handler. You can then access this object in your graph with the langgraph_auth_user key to allow an agent to perform authenticated actions on behalf of the user.
  1. Implement authentication:
    Without a custom @auth.authenticate handler, LangGraph sees only the API-key owner (usually the developer), so requests aren’t scoped to individual end-users. To propagate custom tokens, you must implement your own handler.
from langgraph_sdk import Auth
import requests

auth = Auth()

def is_valid_key(api_key: str) -> bool:
    is_valid = # your API key validation logic
    return is_valid

@auth.authenticate # (1)!
async def authenticate(headers: dict) -> Auth.types.MinimalUserDict:
    api_key = headers.get(b"x-api-key")
    if not api_key or not is_valid_key(api_key):
        raise Auth.exceptions.HTTPException(status_code=401, detail="Invalid API key")

    # Fetch user-specific tokens from your secret store
    user_tokens = await fetch_user_tokens(api_key)

    return { # (2)!
        "identity": api_key,  #  fetch user ID from LangSmith
        "github_token" : user_tokens.github_token
        "jira_token" : user_tokens.jira_token
        # ... custom fields/secrets here
    }
  1. This handler receives the request (headers, etc.), validates the user, and returns a dictionary with at least an identity field.
  2. You can add any custom fields you want (e.g., OAuth tokens, roles, org IDs, etc.).
  3. In your langgraph.json, add the path to your auth file:
{
  "dependencies": ["."],
  "graphs": {
    "agent": "./agent.py:graph"
  },
  "env": ".env",
  "auth": {
    "path": "./auth.py:my_auth"
  }
}
  1. Once you’ve set up authentication in your server, requests must include the required authorization information based on your chosen scheme. Assuming you are using JWT token authentication, you could access your deployments using any of the following methods: 
    from langgraph_sdk import get_client

my_token = "your-token" # In practice, you would generate a signed token with your auth provider
client = get_client(
    url="http://localhost:2024",
    headers={"Authorization": f"Bearer {my_token}"}
)
threads = await client.threads.search()

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Enable agent authentication

After authentication, the platform creates a special configuration object (config) that is passed to LangGraph Platform deployment. This object contains information about the current user, including any custom fields you return from your @auth.authenticate handler. To allow an agent to perform authenticated actions on behalf of the user, access this object in your graph with the langgraph_auth_user key: 
def my_node(state, config):
    user_config = config["configurable"].get("langgraph_auth_user")
    # token was resolved during the @auth.authenticate function
    token = user_config.get("github_token","")
    ...
Fetch user credentials from a secure secret store. Storing secrets in graph state is not recommended.

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Authorizing a Studio user

By default, if you add custom authorization on your resources, this will also apply to interactions made from the Studio. If you want, you can handle logged-in Studio users differently by checking is_studio_user().
is_studio_user was added in version 0.1.73 of the langgraph-sdk. If you’re on an older version, you can still check whether isinstance(ctx.user, StudioUser).
from langgraph_sdk.auth import is_studio_user, Auth
auth = Auth()

# ... Setup authenticate, etc.

@auth.on
async def add_owner(
    ctx: Auth.types.AuthContext,
    value: dict  # The payload being sent to this access method
) -> dict:  # Returns a filter dict that restricts access to resources
    if is_studio_user(ctx.user):
        return {}

    filters = {"owner": ctx.user.identity}
    metadata = value.setdefault("metadata", {})
    metadata.update(filters)
    return filters
Only use this if you want to permit developer access to a graph deployed on the managed LangGraph Platform SaaS.

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