How to Fix 401 Error While Connecting to MCP Servers via LM Studio?

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1

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Hello team. I am trying to connect to mcp servers via LM studio. Since LM Studio doesn’t provide browser oauth it fails with 401. How do I fix it?

2026-03-10 03:02:55 [ERROR]
 [Plugin(mcp/pipedream)] stderr: _0x5cb83d [Error]: SSE error: Non-200 status code (401)
    at <computed>.<computed> (/Applications/LM [Studio.app/Contents/Resources/app/.webpack/lib/mcpbridgeworker.js:29:219091](http://Studio.app/Contents/Resources/app/.webpack/lib/mcpbridgeworker.js:29:219091))
    at _0x1bc705._0x1f6ee2 (/Applications/LM [Studio.app/Contents/Resources/app/.webpack/lib/mcpbridgeworker.js:29:361533](http://Studio.app/Contents/Resources/app/.webpack/lib/mcpbridgeworker.js:29:361533))
    at /Applications/LM [Studio.app/Contents/Resources/app/.webpack/lib/mcpbridgeworker.js:29:355159](http://Studio.app/Contents/Resources/app/.webpack/lib/mcpbridgeworker.js:29:355159)
    at process.processTicksAndRejections (node:internal/process/task_queues:105:5) {
  code: 401,
  event: {
    type: 'error',
    message: 'Non-200 status code (401)',
    code: 401,
    defaultPrevented: false,
    cancelable: false,
    timeStamp: 1188.617125
  }
}
2026-03-10 03:02:55 [DEBUG]
 [LMSAuthenticator][Client=plugin:installed:mcp/pipedream] Client disconnected.
2

here’s to the good old days. Cheers

3

can you please have a look on this one when you get a chance.

4

Yes, I’ll take a look!

5

From the error you provided, the connection is failing with a 401 Unauthorized response when the MCP plugin attempts to establish the SSE connection. This usually indicates that the request is not properly authenticated.

Since LM Studio currently does not support browser-based OAuth flows, the authentication step required by the Pipedream MCP server may not be completing successfully, which would explain the 401 response.

A few things you could try:
• Verify whether the MCP configuration in LM Studio allows you to provide an API key or bearer token manually. If so, try generating a token from your Pipedream account and passing it as an authorization header.
• Check whether the MCP server configuration includes any required environment variables or authentication parameters that may not be set in LM Studio.
• If possible, test the same MCP server using another MCP client that supports OAuth to confirm whether the issue is specific to LM Studio’s authentication limitations.