How to Install MCP Servers in Claude Desktop
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.
Where the config lives
- macOS
~/Library/Application Support/Claude/claude_desktop_config.json - Windows
%APPDATA%\Claude\claude_desktop_config.json
{
"mcpServers": {
"filesystem": {
"command": "npx",
"args": ["-y", "@modelcontextprotocol/server-filesystem", "/path/to/allowed/dir"],
"env": {}
}
}
}Step by step
- 1
Open the config file
In 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.
- 2
Add the server under mcpServers
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.
- 3
Save and fully restart Claude Desktop
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.
- 4
Verify the tools loaded
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).
Popular MCP servers to try in Claude Desktop
Frequently asked questions
Where is the Claude Desktop MCP config file?
On macOS it is ~/Library/Application Support/Claude/claude_desktop_config.json; on Windows it is %APPDATA%\Claude\claude_desktop_config.json. The fastest way to open it is Settings → Developer → Edit Config, which creates the file if it does not exist.
Why does my MCP server show zero tools in Claude Desktop?
The server process usually started but crashed before responding to the tools/list request — commonly a missing environment variable, a bad command path, or non-JSON output on stdout. Open the per-server log at ~/Library/Logs/Claude/mcp*.log to see the actual error.
Do I need to restart Claude Desktop after editing the config?
Yes. Claude Desktop only launches MCP servers at startup, so you must fully quit and reopen the app — closing the window is not enough.