Claude Desktop

You need a personal access token — create one in Profile → API Tokens (guide).

Claude Desktop's connectors can't send custom headers natively, so bridge through mcp-remote (needs Node.js installed). In claude_desktop_config.json (Settings → Developer → Edit Config):

{
  "mcpServers": {
    "writemars": {
      "command": "npx",
      "args": [
        "mcp-remote",
        "https://api.writemars.com/mcp/",
        "--header",
        "X-API-Key:${WRITEMARS_TOKEN}"
      ],
      "env": { "WRITEMARS_TOKEN": "writemars_pat_..." }
    }
  }
}

Restart Claude Desktop; writemars appears under the tools icon.

The X-API-Key:${WRITEMARS_TOKEN} form (no space after :) sidesteps an argument-splitting quirk in some mcp-remote versions.

Connection failing? See troubleshooting. Otherwise, head to the prompt cookbook.