[BUG]

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Summary

The claude.ai GitLab MCP server integration consistently fails to connect. After
completing the OAuth authorization flow on GitLab, the connection still shows as
Failed in the MCP panel.

Environment

• Claude Code: VSCode extension (win32)
• OS: Windows 11 Enterprise 10.0.26100
• Model: claude-sonnet-4-6
• GitLab: gitlab.com (enterprise SAML-managed account)

What Should Happen?

claude.ai GitLab MCP should connect

Error Messages/Logs

## Error from logs
File: %APPDATA%\Code\logs\<session>\window1\exthost\Anthropic.claude-code\Claude VSCode.log

MCP server "claude.ai GitLab" Error: Streamable HTTP error: Error POSTing to endpoint:
{"type":"error","error":{"type":"not_found_error",
"message":"No MCP endpoint was found at the URL provided."},
"request_id":"req_011CZZJQPz9qU3XMRbJJbfNa"}

MCP server "claude.ai GitLab" Connection failed: [same error]


(Retried ~6 times on startup, then again on manual reconnect attempts)

## Analysis
The error suggests Anthropic's proxy is attempting to connect to a GitLab-hosted 
MCP endpoint URL (e.g. https://gitlab.com/api/v4/mcp) which does not exist on 
GitLab's servers. GitLab does not host an MCP server — the integration appears 
to be misconfigured on the claude.ai side, or the expected GitLab MCP endpoint 
URL is wrong/missing.

The OAuth flow itself succeeds (GitLab authorization page appears and redirects 
correctly), but the subsequent MCP connection fails with not_found_error.

Steps to Reproduce

Steps to Reproduce

1. Open MCP panel in Claude Code
2. Find "claude.ai GitLab" — shows Failed
3. Click to configure → GitLab OAuth authorization page appears
4. Authorize the app ("Claude is requesting access to your GitLab account")
5. Redirected back to Claude Code connectors page
6. Server still shows Failed

Claude Model

Sonnet (default)

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.85

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

<img width="674" height="494" alt="Image" src="https://github.com/user-attachments/assets/02ea62ef-849d-4622-a18d-03c631a19125" />
<img width="1021" height="100" alt="Image" src="https://github.com/user-attachments/assets/bc5d5029-034c-4ac6-8d26-1ff49f5dfd53" />