Add the Resend MCP server to Windsurf

Prerequisites

• Windsurf installed.
• RESEND_API_KEY — Your Resend API key (required for stdio mode; optional in HTTP mode where clients pass it as a bearer token).

Setup

{
  "mcpServers": {
    "resend": {
      "command": "npx",
      "args": [
        "-y",
        "resend-mcp"
      ],
      "env": {
        "RESEND_API_KEY": "<RESEND_API_KEY>",
        "SENDER_EMAIL_ADDRESS": "<SENDER_EMAIL_ADDRESS>",
        "REPLY_TO_EMAIL_ADDRESSES": "<REPLY_TO_EMAIL_ADDRESSES>"
      }
    }
  }
}

Gotchas

Windsurf's Cascade reads MCP servers from an "mcpServers" object in ~/.codeium/windsurf/mcp_config.json. Unlike most clients, remote servers are configured with the "serverUrl" field rather than "url", so a config that uses "url" silently fails to connect. Native remote transport is supported without an OAuth flow.