Cursor IDE Integration Fails: Option Disappears After Brief Availability

What this error means

[ERROR] MCP server "ide" Failed to fetch tools: MCP error -32000: Connection closed ... (repeats indefinitely) is a Cursor failure pattern reported for developers trying to fix cursor ide claude code extension disconnecting immediately after launch, /ide command returns no available ides. Based on the imported evidence, treat this as a tool-specific troubleshooting page rather than a generic API error.

Why this happens

GitHub issue #20826 documents Cursor IDE integration failure with repeated WS-IDE reconnection loop. On Windows 11/Cursor 2.4.21/Claude Code 2.1.19, the IDE disconnected flash appears briefly then the Cursor option vanishes entirely from /ide menu. Verified TCP connection and .lock files exist. Confirmed active by user follow-up comments (Feb 2026). Distinct from Claude Code general MCP issues as it specifically targets Cursor IDE bridge. Maps to AI Coding Tools.

Common causes

• GitHub issue #20826 documents Cursor IDE integration failure with repeated WS-IDE reconnection loop. On Windows 11/Cursor 2.4.21/Claude Code 2.1.19, the IDE disconnected flash appears briefly then the Cursor option vanishes entirely from /ide menu. Verified TCP connection and .lock files exist. Confirmed active by user follow-up comments (Feb 2026). Distinct from Claude Code general MCP issues as it specifically targets Cursor IDE bridge. Maps to AI Coding Tools.

Quick fixes

1. Confirm the exact error signature matches [ERROR] MCP server "ide" Failed to fetch tools: MCP error -32000: Connection closed ... (repeats indefinitely).
2. Check the Cursor account, local tool state, and provider configuration involved in the failing workflow.
3. Compare the failing environment with a known working setup, then change one configuration value at a time.

Platform/tool-specific checks

• Verify the command, editor, extension, or API client that produced the error.
• Compare local settings with CI, deployment, or editor-level settings when the error appears in only one environment.
• Avoid deleting credentials, local model data, or project settings until the failing scope is clear.

Step-by-step troubleshooting

1. Capture the exact error message and the command, editor action, or request that triggered it.
2. Check whether the failure is account/auth, quota/rate, model/provider, local runtime, or deployment configuration.
3. Review the source evidence below and compare it with your environment.
4. Apply one change at a time and rerun the smallest failing action.
5. Keep the working fix documented for the team or deployment environment.

How to prevent it

• Keep provider/tool configuration documented.
• Record non-secret diagnostics such as tool version, provider name, model name, and command path.
• Add a lightweight check before CI or production workflows depend on the tool.

Sources checked

• https://github.com/anthropics/claude-code/issues/20826

Evidence note: GitHub issue #20826 documents Cursor IDE integration failure with repeated WS-IDE reconnection loop. On Windows 11/Cursor 2.4.21/Claude Code 2.1.19, the IDE disconnected flash appears briefly then the Cursor option vanishes entirely from /ide menu. Verified TCP connection and .lock files exist. Confirmed active by user follow-up comments (Feb 2026). Distinct from Claude Code general MCP issues as it specifically targets Cursor IDE bridge. Maps to AI Coding Tools.

Related errors

• Cursor

FAQ

What should I check first?

Start with the exact [ERROR] MCP server "ide" Failed to fetch tools: MCP error -32000: Connection closed ... (repeats indefinitely) text and the smallest action that reproduces it.

Can I ignore this error?

No. Treat it as a failed Cursor workflow until the root cause is understood.

Is this guaranteed to have one fix?

No. The imported evidence supports the troubleshooting path above, but tool behavior can vary by account, plan, version, provider, and local configuration.

How do I know the fix worked?

Rerun the same command, editor action, or request. The fix is working when that action completes without [ERROR] MCP server "ide" Failed to fetch tools: MCP error -32000: Connection closed ... (repeats indefinitely).