When chat to Open MCP Client, no response and got GraphQLError

[zhufeizzz]

ErrorLogs

 ✓ Compiled /api/copilotkit in 1297ms
 POST /api/copilotkit 200 in 1791ms
 POST /api/copilotkit 200 in 1800ms
 POST /api/copilotkit 200 in 1804ms
Error getting response: [TypeError: The "data" argument must be of type string or an instance of Buffer, TypedArray, or DataView. Received undefined] {
  code: 'ERR_INVALID_ARG_TYPE'
}
Error getting response: [TypeError: The "data" argument must be of type string or an instance of Buffer, TypedArray, or DataView. Received undefined] {
  code: 'ERR_INVALID_ARG_TYPE'
}
[17:24:26.112] ERROR: The "data" argument must be of type string or an instance of Buffer, TypedArray, or DataView. Received undefined
    component: "Yoga GraphQL"
    err: {
      "type": "GraphQLError",
      "message": "The \"data\" argument must be of type string or an instance of Buffer, TypedArray, or DataView. Received undefined",
      "stack":
          TypeError: The "data" argument must be of type string or an instance of Buffer, TypedArray, or DataView. Received undefined
              at Hash.update (node:internal/crypto/hash:115:11)
              at Object.langGraphAgentHandler (F:\GitHub\LLM\open-mcp-client\.next\server\chunks\a7392_@copilotkit_runtime_dist_index_808c46bc.js:3030:81)
              at CopilotRuntime.processAgentRequest (F:\GitHub\LLM\open-mcp-client\.next\server\chunks\a7392_@copilotkit_runtime_dist_index_808c46bc.js:4204:47)
              at process.processTicksAndRejections (node:internal/process/task_queues:105:5)
              at async CopilotRuntime.processRuntimeRequest (F:\GitHub\LLM\open-mcp-client\.next\server\chunks\a7392_@copilotkit_runtime_dist_index_808c46bc.js:3949:24)
              at async CopilotResolver.generateCopilotResponse (F:\GitHub\LLM\open-mcp-client\.next\server\chunks\a7392_@copilotkit_runtime_dist_index_808c46bc.js:5211:142)
              at async F:\GitHub\LLM\open-mcp-client\.next\server\chunks\node_modules__pnpm_d10eac87._.js:44419:22
              at async handleParams (F:\GitHub\LLM\open-mcp-client\.next\server\chunks\node_modules__pnpm_d10eac87._.js:41657:22)
              at async YogaServer.getResultForParams (F:\GitHub\LLM\open-mcp-client\.next\server\chunks\node_modules__pnpm_d10eac87._.js:41703:20)
              at async handle (F:\GitHub\LLM\open-mcp-client\.next\server\chunks\node_modules__pnpm_d10eac87._.js:41759:24)
      "path": [
        "generateCopilotResponse"
      ],
      "locations": [
        {
          "line": 2,
          "column": 3
        }
      ],
      "extensions": {}
    }
 POST /api/copilotkit 200 in 225ms

[willy20040711]

I have the same problem and try to delete the .langgraph_api file and run "langgraph dev" again. Not sure this can solve your error or not.

[zhufeizzz]

I have the same problem and try to delete the .langgraph_api file and run "langgraph dev" again. Not sure this can solve your error or not.

I'm sorry, this doesn't work for me.

[ta1kun]

same problem here

[Zeeshanunique]

Even I'm facing the same error

[harishreddy69]

Facing same problem

[gfffrtt]

facing the same problem here

[gentlenerJack]

same problem

[SeyZ]

Same. Any news?

[anischihi]

same issue here:
What solved it for me is to add LANGSMITH_API_KEY in .env in both the root and agent folders. even though I do not use langsmith I just added some placeholder value:
LANGSMITH_API_KEY="s"

[tylerslaton]

Hi everyone, thanks for giving this a try and sorry to hear this wasn't working for you from the start.

Yes, the langsmith API key is required to be non-empty. However, when running locally it can be anything. When/if you take this to production it is required by LangGraph to run.

@zhufeizzz could you give this a try and see if it fixes your issue?

[GuilongLu]

I have already set these keys, but I still get an error.

[abc-w]

大家好，感谢您尝试此作，很遗憾听到这从一开始就对您不起作用。

是的，langsmith API 密钥必须为非空。但是，在本地运行时，它可以是任何内容。当你将其用于生产环境时/如果将其用于生产环境，则 LangGraph 需要它才能运行。

您能否试一试，看看它是否能解决您的问题？

This doesn't work

[africa-reforestation]

Simply create a free langsmith account for developer, then get the api_key paste it it will work see:

Advantage of langsmith is helps you trace the llm calls and understand what happens under the hood

[abc-w]

i am already got langsmith api key as the picture  i above，but i dose not work

…

---Original--- From: ***@***.***> Date: Fri, Mar 28, 2025 19:45 PM To: ***@***.***>; Cc: "Wan ***@***.******@***.***>; Subject: Re: [CopilotKit/open-mcp-client] When chat to Open MCP Client, noresponse and got GraphQLError (Issue #11) Screenshot.from.2025-03-28.14-28-37.png (view on web) Simply create a free langsmith account for developer, then get the api_key paste it it will work see: Screenshot.from.2025-03-28.14-43-26.png (view on web) Advantage of langsmith is helps you trace the llm calls and understand what happens under the hood — Reply to this email directly, view it on GitHub, or unsubscribe. You are receiving this because you commented.Message ID: ***@***.***> africa-reforestation left a comment (CopilotKit/open-mcp-client#11) Screenshot.from.2025-03-28.14-28-37.png (view on web) Simply create a free langsmith account for developer, then get the api_key paste it it will work see: Screenshot.from.2025-03-28.14-43-26.png (view on web) Advantage of langsmith is helps you trace the llm calls and understand what happens under the hood — Reply to this email directly, view it on GitHub, or unsubscribe. You are receiving this because you commented.Message ID: ***@***.***>

[africa-reforestation]

Which model are you using?

[Ghostdar]

same error ,, i try to use anthropic model ,, it can't work