MCP error -32601: Method not found on claude-vscode server #23248
Description
Bug Description
The Claude Code extension in Cursor fails to fetch tools from the MCP server with error:
MCP error -32601: Method not found
The error appears in the Output panel as:
2026-02-04 18:37:49.574 [info] From claude: 2026-02-05T02:37:49.573Z [ERROR] MCP server "claude-vscode" Failed to fetch tools: MCP error -32601: Method not found
Environment
- Extension version: 2.1.31-darwin-arm64
- IDE: Cursor
- OS: macOS (Darwin 25.3.0, arm64)
- Date: 2026-02-04
Reproduction Steps
- Install Claude Code extension in Cursor
- Open a project
- Try to use the extension
- Error appears in Output panel
What I've Tried
- Killed all stale extension processes (had multiple running)
- Reloaded Cursor window
- Error persists even with a single clean extension process
Analysis
The error -32601 is the JSON-RPC standard error for "Method not found". This suggests the extension is calling a method on the claude-vscode MCP server that doesn't exist or isn't implemented.
The extension spawns correctly and the process args show it's configured to use:
{"mcpServers":{"claude-vscode":{"type":"sdk","name":"claude-vscode"}}}But the MCP server doesn't recognize whatever method is being called during tool fetching.
Expected Behavior
Extension should successfully fetch tools and be responsive.
Actual Behavior
Extension is completely unresponsive. Cannot interact with it at all.