How to install and configure MCP servers in Claude Desktop on macOS and Windows — the config file location, the exact JSON shape, and how to verify your tools loaded.
Browse Claude Desktop servers directoryIn Claude Desktop, go to Settings → Developer → Edit Config. This opens (or creates) claude_desktop_config.json in your text editor. You can also open the file directly at the path for your OS.
Add an entry inside the "mcpServers" object with a name, a "command", and its "args". Put any secrets in the "env" object rather than inline in the args.
Quit Claude Desktop completely (not just the window) and reopen it. MCP servers are only launched on startup, so config edits are ignored until a full restart.
Open a new chat and look for the tools/MCP indicator. If the server shows zero tools or an error, check the MCP log at ~/Library/Logs/Claude/mcp*.log (macOS) or %APPDATA%\Claude\logs (Windows).
claude_desktop_config.json~/Library/Application Support/Claude/claude_desktop_config.json{
"mcpServers": {
"filesystem": {
"command": "npx",
"args": ["-y", "@modelcontextprotocol/server-filesystem", "/path/to/allowed/dir"],
"env": {}
}
}
}domain_check_v1 in a loop.