How to Install MCP in Claude Desktop (No JSON)

The manual way: editing claude_desktop_config.json

If you prefer doing it by hand (or the server is private and not in any catalog), open Claude Desktop → Settings → Developer → Edit Config. That opens claude_desktop_config.json directly. On macOS the file lives at ~/Library/Application Support/Claude/claude_desktop_config.json, on Windows at %APPDATA%\Claude\claude_desktop_config.json. Add your server under the mcpServers key — command is the executable, args its arguments, env holds API keys. Save, then fully restart Claude Desktop.

{
  "mcpServers": {
    "github": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-github"],
      "env": {
        "GITHUB_PERSONAL_ACCESS_TOKEN": "ghp_..."
      }
    }
  }
}

Desktop Extensions (.mcpb) — the official one-click bundles

Anthropic also ships Desktop Extensions: an MCP server packed into a single .mcpb file (formerly .dxt) with its runtime included. Claude Desktop → Settings → Extensions, then drag the .mcpb file in or pick one from the built-in directory — no Node.js, no config. The built-in directory is small and vendor-curated; for everything else, the Unyly catalog generates the config or deep-link for any of its 80,000+ servers. Both approaches coexist fine on one machine.

Troubleshooting: server not showing up

Checklist, in order of likelihood. 1) Claude Desktop was not fully quit — close it from the menu bar / system tray (Cmd+Q on Mac), not just the window. 2) Broken JSON — a trailing comma or missing brace makes Claude silently ignore the whole file; validate it in any JSON linter. 3) Node.js not found — npx-based servers need Node in PATH; if you use nvm, put the absolute path to node in command instead. 4) Check the logs: ~/Library/Logs/Claude/mcp*.log on macOS, %APPDATA%\Claude\logs on Windows — startup errors of every server land there. A healthy server shows up under the tools icon in the chat input.