Claude Desktop

Claude Desktop reaches a remote server that takes a header through mcp-remote, which needs Node.js. Replace onss_live_… with your key, or copy the config from the dialog that showed the key: it has the key in it already.

Open the config file

In Claude Desktop, open Settings › Developer › Edit Config. It opens claude_desktop_config.json.

Add the server

If the file has no other server, replace its contents with this. If it has, add onosso inside its mcpServers.

claude_desktop_config.json

{
  "mcpServers": {
    "onosso": {
      "command": "npx",
      "args": [
        "-y",
        "mcp-remote",
        "https://app.onosso.app/v1/mcp",
        "--header",
        "Authorization:${ONOSSO_AUTHORIZATION}"
      ],
      "env": {
        "ONOSSO_AUTHORIZATION": "Bearer onss_live_…"
      }
    }
  }
}

The key goes in env rather than in args because some systems split an argument at its space.

Restart Claude Desktop

Quit it and open it again: it reads the config only when it starts.

MCP guide

Connect

Reference