Connect Claude Desktop to any MCP server.
Local servers go in claude_desktop_config.json; remote servers connect by URL. The mechanics, the file paths, and the restart-and-logs ritual that fixes most failures.
Claude Desktop talks to MCP servers two ways: it can spawn a local server as a child process over stdio, or connect to a remote server by URL. Which path you use depends entirely on how the server you want is distributed.
Local servers are configured in a JSON file you edit by hand; remote ones are added through the app's connector settings. Both take a minute when they work — and both fail silently enough that knowing where the logs live is half this guide's value.
Find the config file
Local servers are declared in claude_desktop_config.json. On macOS it lives at ~/Library/Application Support/Claude/claude_desktop_config.json; on Windows, %APPDATA%\Claude\claude_desktop_config.json. If the file doesn't exist yet, the Developer section of the app's settings can create and open it for you.
Each entry names a command for Claude Desktop to spawn. The app launches the process, speaks JSON-RPC to it over stdin/stdout, and surfaces the server's tools in the chat interface.
Add a local server
Most local servers ship on npm or PyPI, so the command is typically npx or uvx with the package name. The example below wires up the reference filesystem server, scoped to one directory — swap in any server's package name and arguments from its README.
{
"mcpServers": {
"filesystem": {
"command": "npx",
"args": [
"-y",
"@modelcontextprotocol/server-filesystem",
"/Users/you/Projects"
]
}
}
}Add a remote server
Servers hosted as remote endpoints don't go in the config file the same way — Claude Desktop adds them as connectors. In Settings, add a custom connector with the server's URL (a Streamable HTTP endpoint such as https://mcp.example.dev/mcp); if the server uses OAuth, the app walks you through the sign-in.
For remote servers that a given setup can't reach directly, the mcp-remote bridge is the standard workaround: configure a local entry whose command is npx mcp-remote <url>, and the bridge proxies stdio to the remote endpoint.
Verify, then troubleshoot
After any config change, quit Claude Desktop completely (Cmd+Q on macOS — closing the window isn't enough) and relaunch. Working servers show up under the tools icon in the chat input; ask Claude to list its tools if you're unsure.
When a server doesn't appear, read the logs: macOS keeps them in ~/Library/Logs/Claude/ (mcp.log for the app side, mcp-server-<name>.log per server), Windows under %APPDATA%\Claude\logs. The classic failures are a JSON syntax error in the config, a command that isn't on Claude Desktop's PATH — use an absolute path to npx or node if needed — and relative directory arguments where absolute paths are required.
Finding servers worth connecting
The Loomal Index lists MCP servers with their live tool lists, install metadata, and remote URLs, which makes it a practical first stop before editing config — you can see exactly what tools a server exposes before installing it.
Some listed servers are paid: their endpoints quote a per-call price (from $0.01) over x402 and expect the caller to pay in USDC before the tool runs. Claude Desktop has no built-in payment wallet as of mid-2026, so paid endpoints are primarily aimed at agent frameworks with wallets attached — check a listing's details to see what's required.
FAQ
Why doesn't my server show up after I edited the config?
Usually one of three things: the JSON has a syntax error (a trailing comma is the classic), the app wasn't fully restarted — quit it entirely, don't just close the window — or the command can't be found because npx or uvx isn't on the PATH Claude Desktop inherits. The per-server log file will tell you which.
Can Claude Desktop connect to a remote MCP server directly?
Yes — add it as a custom connector in Settings using the server's URL, with OAuth handled in-app when the server requires it. The mcp-remote bridge remains a fallback for setups where a stdio-style config entry is more practical.
Where are the MCP logs for Claude Desktop?
On macOS, ~/Library/Logs/Claude/ — mcp.log covers connection-level events and each server gets its own mcp-server-<name>.log with its stderr output. On Windows, look under %APPDATA%\Claude\logs. Tail the per-server log while restarting to catch startup errors live.
Can Claude Desktop call x402-paid MCP servers?
Not natively — paying requires a wallet that can sign USDC authorizations, which Claude Desktop doesn't include as of mid-2026. Paid Loomal endpoints are built for wallet-equipped agents and proxies; the free tier of a server, where one exists, works in Claude Desktop like any other connector.
Pick a server to connect.
Browse live tool lists on the Loomal Index before you edit a single config file.