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Troubleshooting

MCP server not showing up in Claude Desktop

Claude Desktop only reads claude_desktop_config.json when it starts, and it skips the whole file if the JSON is invalid. Check the file is valid JSON, that the server sits inside "mcpServers", then quit Claude Desktop fully and open it again. If it still fails, the MCP log files show the exact error.

Claude Desktop

Why it happens

  • The JSON has a typo, such as a trailing comma or a missing quote.
  • The server was added outside the "mcpServers" block.
  • Claude Desktop was not fully restarted.
  • The server command fails when it starts.

How to fix it

  1. 1

    Validate the config file

    Open Settings, then Developer, then Edit Config. Paste the file into any JSON validator. Remove trailing commas and make sure every key is in double quotes.

  2. 2

    Quit and reopen

    Closing the window is not enough. Quit from the menu bar (macOS) or the system tray (Windows), then open the app again.

  3. 3

    Read the MCP logs

    On macOS the logs are in ~/Library/Logs/Claude/, on Windows in %APPDATA%\Claude\logs\. Files named mcp*.log show why a server failed.

  4. 4

    Run the command yourself

    Copy the command and args into a terminal and run them. If it fails there, fix that first (missing Node.js, uv or API key).

Still stuck? Every server page on this site shows the exact config for each app. Find your server.