Run the MCP server locally

@emailit/emailit-mcp is the open-source version of the Emailit MCP server. It runs on your machine, talks to the Emailit API with your API key, and works with clients that only support local (stdio) servers. Most people should use the hosted server instead; this page explains when the local package makes sense and how to configure it.

• Package: @emailit/emailit-mcp on npm
• Source: github.com/emailit/emailit-mcp, MIT license
• Runtime: Node.js 18 or later

Local or hosted

Choose the local package when:

• your client only supports stdio servers, or can’t do OAuth for remote servers,
• you want a default From and Reply-To address applied to every send, or
• you want to read, pin or modify the server code.

Before you begin

• Node.js 18 or later, so npx is available.
• An API key. Use a Sending Only key, restricted to one domain, if the assistant only needs to send; the other tools need Full Access.
• A verified sending domain for the sender address.

Configure your client

The client starts the server as a subprocess and talks to it over stdio. Pass the API key through the EMAILIT_API_KEY environment variable.

claude mcp add emailit \
  -e EMAILIT_API_KEY=secret_•••••••• \
  -e SENDER_EMAIL_ADDRESS=hello@acme.com \
  -- npx -y @emailit/emailit-mcp

{
  "mcpServers": {
    "emailit": {
      "command": "npx",
      "args": ["-y", "@emailit/emailit-mcp"],
      "env": {
        "EMAILIT_API_KEY": "secret_••••••••",
        "SENDER_EMAIL_ADDRESS": "hello@acme.com"
      }
    }
  }
}

{
  "mcpServers": {
    "emailit": {
      "command": "npx",
      "args": ["-y", "@emailit/emailit-mcp"],
      "env": {
        "EMAILIT_API_KEY": "secret_••••••••",
        "SENDER_EMAIL_ADDRESS": "hello@acme.com"
      }
    }
  }
}

{
  "inputs": [
    { "type": "promptString", "id": "emailit-api-key", "description": "Emailit API key", "password": true }
  ],
  "servers": {
    "emailit": {
      "type": "stdio",
      "command": "npx",
      "args": ["-y", "@emailit/emailit-mcp"],
      "env": {
        "EMAILIT_API_KEY": "${input:emailit-api-key}",
        "SENDER_EMAIL_ADDRESS": "hello@acme.com"
      }
    }
  }
}

Always use the scoped package name, @emailit/emailit-mcp.

Environment variables

If you don’t set a sender, the server asks the assistant for a From address on each send.

Command-line flags

Flags override the matching environment variables.

Run over HTTP

To share one local server between several clients, start it in HTTP mode:

npx -y @emailit/emailit-mcp --http --port 3000

The server listens on http://127.0.0.1:3000/mcp and is only reachable from your machine. Each client authenticates with its own API key as a bearer token:

claude mcp add emailit --transport http http://127.0.0.1:3000/mcp \
  --header "Authorization: Bearer $EMAILIT_API_KEY"

Run from source

git clone https://github.com/emailit/emailit-mcp.git
cd emailit-mcp
npm install
EMAILIT_API_KEY=secret_•••••••• node src/index.js

Add --http --port 3000 to the last command for HTTP mode.

Troubleshooting

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