MailerAstro MCP Server

> The email API for AI agents — now available as an MCP server.

Send transactional emails, check wallet balances, and query reputation scores — all paid with USDC on Base via the x402 protocol. No API keys. No accounts. No subscriptions. Just your wallet.

Quick Start

Remote (Streamable HTTP)

Connect any MCP-compatible client to the hosted server:

https://mcp.mailerastro.com/mcp

Local (stdio)

npx mailerastro-mcp-server

Or install globally:

npm install -g mailerastro-mcp-server
TRANSPORT=stdio mailerastro-mcp

Claude Desktop Config

Add to your claude_desktop_config.json:

{
  "mcpServers": {
    "mailerastro": {
      "command": "npx",
      "args": ["mailerastro-mcp-server"],
      "env": {
        "MAILERASTRO_API_URL": "https://api.mailerastro.com"
      }
    }
  }
}

Tools

| Tool | Description | Cost |
|------|-------------|------|
| mailerastro_get_started | Onboarding guide for new agents | Free |
| mailerastro_send_email | Send a single transactional email | $0.001 (text) / $0.005 (HTML) |
| mailerastro_send_batch | Send up to 50 emails in one call | 10% batch discount |
| mailerastro_check_balance | Check your USDC wallet balance | Free |
| mailerastro_get_reputation | Query agent reputation score & tier | Free |
| mailerastro_get_send_history | View email delivery history | Free |

How It Works

Your AI Agent
    ↓ MCP tool call (mailerastro_send_email)
MailerAstro MCP Server
    ↓ x402 payment validation (USDC on Base)
MailerAstro API
    ↓ SMTP
Email Delivered ✅

1. Your wallet = your identity. No API keys needed. Pass your 0x... wallet address with every call.
2. Pay per email. USDC is deducted from your wallet balance automatically via the x402 protocol.
3. Build reputation. Consistent, high-quality sending earns higher tier status (Bronze → Silver → Gold → Platinum).
4. No sign-up required. Your account is created automatically on first use.

Pricing

| Email Type | Per Email | Batch (10% off) |
|-----------|-----------|------------------|
| Plain text | $0.001 | $0.0009 |
| HTML | $0.005 | $0.0045 |

Reputation System

| Tier | Score | Benefits |
|------|-------|----------|
| 🥉 Bronze | 0-25 | Basic sending |
| 🥈 Silver | 26-50 | Standard rate limits (default for new agents) |
| 🥇 Gold | 51-75 | Priority delivery |
| 💎 Platinum | 76-100 | Highest limits, premium support |

Environment Variables

| Variable | Default | Description |
|----------|---------|-------------|
| MAILERASTRO_API_URL | https://api.mailerastro.com | API backend URL |
| TRANSPORT | stdio | Transport: stdio or http |
| PORT | 3001 | HTTP server port (when TRANSPORT=http) |

Self-Hosting

Deploy to Railway or any Node.js host:

git clone https://github.com/BossLadyMailerAstro/mailerastro-mcp-server.git
cd mailerastro-mcp-server
npm install
npm run build
TRANSPORT=http PORT=3001 npm start

Railway Deployment

1. Connect your GitHub repo to Railway
2. Set environment variables:
- TRANSPORT=http
- PORT=3001
- MAILERASTRO_API_URL=https://api.mailerastro.com
3. Deploy — Railway auto-detects the Node.js project

Development

npm install
npm run dev    # Watch mode with tsx
npm run build  # Compile TypeScript
npm start      # Run compiled server

Architecture

src/
├── index.ts           # Entry point, transport setup
├── constants.ts       # Pricing, limits, config
├── types.ts           # TypeScript interfaces
├── schemas/
│   └── index.ts       # Zod validation schemas
├── services/
│   └── api-client.ts  # MailerAstro API HTTP client
└── tools/
    ├── email.ts       # send_email, send_batch
    ├── wallet.ts      # check_balance, get_reputation, get_send_history
    └── onboarding.ts  # get_started

Links

- Website: mailerastro.com
- API Docs: mailerastro.com/docs
- Fund Wallet: bridge.base.org

License

MIT