Cursor / Cursor

Cursor IDE Integration Fails: Option Disappears After Brief Availability

Fix Cursor IDE Claude Code extension disconnecting immediately after launch, /ide command returns no available IDEs Includes evidence for Cursor troubleshooting demand.

Source-backed Last updated May 22, 2026 1 source Needs local verification

Category: Cursor
Error signature: [ERROR] MCP server "ide" Failed to fetch tools: MCP error -32000: Connection closed ... (repeats indefinitely)
Quick fix: Compare the failing environment with a known working setup, then change one configuration value at a time.
Updated: May 22, 2026
Verification status: Source-backed
Evidence: 1 public source URL

Before you change production

This page includes public source URLs in the imported troubleshooting record. Compare those references with your version and environment before applying changes.

Reproduce the smallest failing action and save non-secret logs before changing configuration.
Check versions for Cursor, related SDKs, package managers, CI runners, and hosting providers.
Change one setting or dependency at a time, then rerun the same failing command or request.
Avoid destructive commands, credential rotation, billing changes, or security relaxations without a rollback plan.

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

Confirm the exact error signature matches [ERROR] MCP server "ide" Failed to fetch tools: MCP error -32000: Connection closed ... (repeats indefinitely).
Check the Cursor account, local tool state, and provider configuration involved in the failing workflow.
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

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

Diagnostic flow for this page

Match [ERROR] MCP server "ide" Failed to fetch tools: MCP error -32000: Connection closed ... (repeats indefinitely) exactly before applying the quick fix.
Compare the failing environment with Cursor versions, account scope, provider settings, and deployment context.
Check the listed common causes in order, starting with the cause that best matches your logs.
Use the evidence status below to decide whether to confirm against public sources or official documentation.
Apply one reversible change, rerun the smallest failing action, and keep rollback notes.

FAQ

What does [ERROR] MCP server "ide" Failed to fetch tools: MCP error -32000: Connection closed ... (repeats indefinitely) mean in Cursor?

[ERROR] MCP server "ide" Failed to fetch tools: MCP error -32000: Connection closed ... (repeats indefinitely) indicates the workflow described by "Cursor IDE Integration Fails: Option Disappears After Brief Availability" failed in a Cursor context. Start by confirming the exact signature and the component that emitted it.

What should I check first for [ERROR] MCP server "ide" Failed to fetch tools: MCP error -32000: Connection closed ... (repeats indefinitely)?

Check whether this cause matches your environment: 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.

Is the [ERROR] MCP server "ide" Failed to fetch tools: MCP error -32000: Connection closed ... (repeats indefinitely) guidance source-backed?

The "Cursor IDE Integration Fails: Option Disappears After Brief Availability" page is labeled source-backed. It has 1 public source URL from github.com, so use that evidence status when deciding how much additional verification you need.

When should I avoid the quick fix for [ERROR] MCP server "ide" Failed to fetch tools: MCP error -32000: Connection closed ... (repeats indefinitely)?

For "Cursor IDE Integration Fails: Option Disappears After Brief Availability", avoid applying "Compare the failing environment with a known working setup, then change one configuration value at a time." when the error text differs, the affected version or provider is different, or the change would touch credentials, billing, DNS, production deploy settings, or irreversible data.

What should I collect before debugging [ERROR] MCP server "ide" Failed to fetch tools: MCP error -32000: Connection closed ... (repeats indefinitely)?

For "Cursor IDE Integration Fails: Option Disappears After Brief Availability", collect the failing Cursor command or request, non-secret configuration, versions, timestamps, request IDs when available, and the smallest reproduction that still triggers the signature.