Barrel Of Lube•2w ago

MCPs refuses to connect

this is making me go crazy, the server is clearly connecting on the backend yet this somehow fails, and no detailed error? what does not connected mean 😭 i even have eventsouce, eventsource extended installed also tried streamable http i also have "use node" on the top n everything, please liberate me. I couldn't sleep the entire night. mcp ts docs: https://github.com/modelcontextprotocol/typescript-sdk#writing-mcp-clients

GitHub

GitHub - modelcontextprotocol/typescript-sdk: The official Typescri...

The official Typescript SDK for Model Context Protocol servers and clients - modelcontextprotocol/typescript-sdk

5 Replies

Barrel Of LubeOP•2w ago

plus the debugging process was horrible as well the console kept on showing dangling promises, and i never leave my promises dangling, am a man of my wrds this thing took 10 yrs off my life n still no solution

Barrel Of LubeOP•2w ago

console logs the backend just crashes after 1 dangling promise error

node:internal/process/promises:288

            triggerUncaughtException(err, true /* fromPromise */);

            ^


Error

    at agent (convex:/user/_deps/node/3IWAJU33.js:16140:23)

    at processTicksAndRejections (node:internal/process/task_queues:95:5)

    at async invoke (convex:/user/_deps/node/3IWAJU33.js:9127:21)

    at async invoke (convex:/user/_deps/node/BUGYJOSP.js:20091:25)

    at async _runWithRetry (convex:/user/_deps/node/3IWAJU33.js:11800:16)

    at async _executeTasksWithRetry (convex:/user/_deps/node/3IWAJU33.js:12103:27)

    at async tick (convex:/user/_deps/node/3IWAJU33.js:11903:58)

    at async _runLoop (convex:/user/_deps/node/3IWAJU33.js:13376:9)

    at async createAndRunLoop (convex:/user/_deps/node/3IWAJU33.js:13282:9) {

  pregelTaskId: '4e4929ab-c305-506b-a23f-8585df8fdd07'

}

node:internal/process/promises:288

            triggerUncaughtException(err, true /* fromPromise */);

            ^


Error

    at agent (convex:/user/_deps/node/3IWAJU33.js:16140:23)

    at processTicksAndRejections (node:internal/process/task_queues:95:5)

    at async invoke (convex:/user/_deps/node/3IWAJU33.js:9127:21)

    at async invoke (convex:/user/_deps/node/BUGYJOSP.js:20091:25)

    at async _runWithRetry (convex:/user/_deps/node/3IWAJU33.js:11800:16)

    at async _executeTasksWithRetry (convex:/user/_deps/node/3IWAJU33.js:12103:27)

    at async tick (convex:/user/_deps/node/3IWAJU33.js:11903:58)

    at async _runLoop (convex:/user/_deps/node/3IWAJU33.js:13376:9)

    at async createAndRunLoop (convex:/user/_deps/node/3IWAJU33.js:13282:9) {

  pregelTaskId: '4e4929ab-c305-506b-a23f-8585df8fdd07'

}

itz easier to show the issue on call ok it seems its not an mcp issue but the database mutation having the issue

Barrel Of LubeOP•2w ago

update: after setting the rust log level to debug in backend, the issue seems to be cuz of size limits + add better error reporting

5/26/2025, 11:09:27 AM [CONVEX A(mcps/actions:start)] [ERROR] 'Error processing event chunk:' Error
    at performAsyncSyscall (convex:/user/_deps/node/CSMA7BBL.js:947:11)
    at processTicksAndRejections (node:internal/process/task_queues:95:5)
    at async runMutation (convex:/user/_deps/node/CSMA7BBL.js:1017:22)
    at async processEvent (convex:/user/langchain/index.js:79:9)
    at async handler (convex:/user/langchain/index.js:97:9)
    at async invokeFunction (convex:/user/_deps/node/CSMA7BBL.js:1301:14)
    at async invokeAction (convex:/user/_deps/node/CSMA7BBL.js:1370:18)
    at async executeInner (bundledFunctions.js:56803:17)
    at async execute (bundledFunctions.js:56742:19)
    at async invoke (bundledFunctions.js:56710:14)

5/26/2025, 11:09:27 AM [CONVEX A(mcps/actions:start)] [ERROR] 'Error processing event chunk:' Error
    at performAsyncSyscall (convex:/user/_deps/node/CSMA7BBL.js:947:11)
    at processTicksAndRejections (node:internal/process/task_queues:95:5)
    at async runMutation (convex:/user/_deps/node/CSMA7BBL.js:1017:22)
    at async processEvent (convex:/user/langchain/index.js:79:9)
    at async handler (convex:/user/langchain/index.js:97:9)
    at async invokeFunction (convex:/user/_deps/node/CSMA7BBL.js:1301:14)
    at async invokeAction (convex:/user/_deps/node/CSMA7BBL.js:1370:18)
    at async executeInner (bundledFunctions.js:56803:17)
    at async execute (bundledFunctions.js:56742:19)
    at async invoke (bundledFunctions.js:56710:14)

ugh ig ill have to breakdown the chunks

MCPs refuses to connect

Did you find this page helpful?