Truelist MCP server

truelist-mcp

MCP (Model Context Protocol) server for Truelist email validation. Lets AI assistants like Claude, Cursor, and VS Code Copilot validate email addresses for deliverability.

What is this?

This package exposes Truelist's email validation API as MCP tools. Once configured, your AI assistant can:

• Check if an email address is valid and deliverable
• Validate batches of emails at once
• Check your Truelist account info and plan

Start free — 100 validations + 10 enhanced credits, no credit card required.

Get your API key →

Works with the free plan.

Installation

npm install -g truelist-mcp

Or run directly with npx:

npx truelist-mcp

Configuration

You need a Truelist API key. Get one at truelist.io.

Claude Desktop

Add to your claudedesktopconfig.json:

macOS: ~/Library/Application Support/Claude/claudedesktopconfig.json Windows: %APPDATA%\Claude\claudedesktopconfig.json

{
  "mcpServers": {
    "truelist": {
      "command": "npx",
      "args": ["truelist-mcp"],
      "env": {
        "TRUELIST_API_KEY": "your-api-key"
      }
    }
  }
}

Claude Code

Add to your .claude/settings.json or run:

claude mcp add truelist -- npx truelist-mcp

Then set the environment variable:

export TRUELIST_API_KEY=your-api-key

Cursor

Add to your Cursor MCP settings (.cursor/mcp.json in your project or global settings):

{
  "mcpServers": {
    "truelist": {
      "command": "npx",
      "args": ["truelist-mcp"],
      "env": {
        "TRUELIST_API_KEY": "your-api-key"
      }
    }
  }
}

VS Code (GitHub Copilot)

Add to your VS Code settings (.vscode/mcp.json in your project):

{
  "servers": {
    "truelist": {
      "command": "npx",
      "args": ["truelist-mcp"],
      "env": {
        "TRUELIST_API_KEY": "your-api-key"
      }
    }
  }
}

Tools

validate_email

Validate a single email address for deliverability.

Input:

{
  "email": "user@example.com"
}

Output:

{
  "email": "user@example.com",
  "state": "ok",
  "sub_state": "email_ok",
  "suggestion": null,
  "domain": "example.com",
  "canonical": "user@example.com",
  "mx_record": "mx.example.com",
  "first_name": "Jane",
  "last_name": "Doe",
  "verified_at": "2026-02-21T12:00:00Z",
  "is_valid": true,
  "is_deliverable": true
}

States:

Sub-states:

validate_emails

Validate multiple email addresses in a single batch (max 50).

Input:

{
  "emails": [
    "user@example.com",
    "test@invalid.example",
    "hello@gmail.com"
  ]
}

Shortened. The full README is on GitHub.