Common LangGraph issues
Common issues you may encounter when using LangGraph.
Welcome to the CoAgents Troubleshooting Guide! If you're having trouble getting tool calls to work, you've come to the right place.
Have an issue not listed here? Open a ticket on GitHub or reach out on Discord and we'll be happy to help.
We also highly encourage any open source contributors that want to add their own troubleshooting issues to Github as a pull request.
My tool calls are not being streamed
This could be due to a few different reasons.
First, we strongly recommend checking out our Human In the Loop guide to follow a more in depth example of how to stream tool calls in your LangGraph agents. You can also check out our travel tutorial which talks about how to stream tool calls in a more complex example.
If you have already done that, you can check the following:
Error: 'AzureOpenAI' object has no attribute 'bind_tools'
This error is typically due to the use of an incorrect import from LangGraph. Instead of importing AzureOpenAI import AzureChatOpenAI and your
issue will be resolved.
from langchain_openai import AzureOpenAI
from langchain_openai import AzureChatOpenAI I am getting "agent not found" error
If you're seeing this error, it means CopilotKit couldn't find the LangGraph agent you're trying to use. Here's how to fix it:
Connection issues with tunnel creation
If you notice the tunnel creation process spinning indefinitely, your router or ISP might be blocking the connection to CopilotKit's tunnel service.
I am getting "Failed to find or contact remote endpoint at url, Make sure the API is running and that it's indeed a LangGraph platform url" error
If you're seeing this error, it means the LangGraph platform client cannot connect to your endpoint.
I am getting a "No checkpointer set" error when using LangGraph with FastAPI
If you're encountering this error, it means you are missing a checkpointer in your compiled graph. You can visit the LangGraph Persistence guide to understand what a checkpointer is and how to add it.
I see messages being streamed and disappear
LangGraph agents are stateful. As a graph is traversed, the state is saved at the end of each node. CopilotKit uses the agent's state as the source of truth for what to display in the frontend chat. However, since state is only emitted at the end of a node, CopilotKit allows you to stream predictive state updates in the middle of a node. By default, CopilotKit will stream messages and tool calls being actively generated to the frontend chat that initiated the interaction. If this predictive state is not persisted at the end of the node, it will disappear in the frontend chat.
In this situation, the most likely scenario is that the messages property in the state is being updated in the middle of a node but those edits are not being
persisted at the end of a node.
