LangGraph Studio troubleshooting

Safari Connection Issues

Safari blocks plain-HTTP traffic on localhost. When running Studio with langgraph dev, you may see “Failed to load assistants” errors.

Solution 1: Use Cloudflare Tunnel

Python

pip install -U langgraph-cli>=0.2.6
langgraph dev --tunnel

The command outputs a URL in this format:

https://smith.langchain.com/studio/?baseUrl=https://hamilton-praise-heart-costumes.trycloudflare.com

Use this URL in Safari to load Studio. Here, the baseUrl parameter specifies your agent server endpoint.

Solution 2: Use Chromium Browser

Chrome and other Chromium browsers allow HTTP on localhost. Use langgraph dev without additional configuration.

Brave Connection Issues

Brave blocks plain-HTTP traffic on localhost when Brave Shields are enabled. When running Studio with langgraph dev, you may see “Failed to load assistants” errors.

Solution 1: Disable Brave Shields

Disable Brave Shields for LangSmith using the Brave icon in the URL bar.

Solution 2: Use Cloudflare Tunnel

Python

pip install -U langgraph-cli>=0.2.6
langgraph dev --tunnel

The command outputs a URL in this format:

https://smith.langchain.com/studio/?baseUrl=https://hamilton-praise-heart-costumes.trycloudflare.com

Use this URL in Brave to load Studio. Here, the baseUrl parameter specifies your agent server endpoint.

Graph Edge Issues

Undefined conditional edges may show unexpected connections in your graph. This is because without proper definition, LangGraph Studio assumes the conditional edge could access all other nodes. To address this, explicitly define the routing paths using one of these methods:

Solution 1: Path Map

Define a mapping between router outputs and target nodes:

Python

graph.add_conditional_edges("node_a", routing_function, {True: "node_b", False: "node_c"})

Solution 2: Router Type Definition

Specify possible routing destinations using Python’s Literal type:

def routing_function(state: GraphState) -> Literal["node_b","node_c"]:
    if state['some_condition'] == True:
        return "node_b"
    else:
        return "node_c"