Solmail
Send physical mail with Solana cryptocurrency - AI agents can send real letters worldwide
Runs on your machine from its package; the steps are below.
What it does
- Reads
- Writes
- High impact
At most: moves money, runs code or commands, deletes data, or sends messages for you.
What it costs
FreeOdel charges nothing per call. The publisher may charge for its own service.
Runs locally over stdio
This server isn't hosted — your MCP client launches it from a package registry. Use one of the commands below, or drop the config into your client (e.g. Claude Desktop).
Run
npx -y solmail-mcp
MCP client config
{
"mcpServers": {
"solmail": {
"command": "npx",
"args": [
"-y",
"solmail-mcp"
]
}
}
}📬 solmail-mcp
Send real physical mail using Solana cryptocurrency from your AI agent. A Model Context Protocol server that enables Claude and other AI agents to send physical letters and postcards to real addresses worldwide, paid with SOL. Built for the Colosseum Agent Hackathon (#47).
Install
npx solmail-mcp@latest
Add to your MCP config:
{
"mcpServers": {
"solmail": {
"command": "npx",
"args": ["-y", "solmail-mcp"],
"env": {
"SOLANA_NETWORK": "devnet",
"SOLANA_PRIVATE_KEY": "your_base58_private_key"
}
}
}
}
Features
- Physical Mail -- Letters printed and mailed to 200+ countries via Lob.com
- Solana Payments -- Pay with SOL on devnet (testing) or mainnet (production)
- Non-Custodial -- Direct wallet control, no intermediaries
- AI-Native -- Built specifically for MCP agent integration
- Demo Mode -- Test with devnet SOL and Lob test API at zero cost
Tools (4)
| Tool | Description |
|---|---|
get_mail_quote | Get price quote for sending mail (country, color options) |
send_mail | Send a physical letter with Solana payment |
get_wallet_balance | Check agent wallet SOL balance |
get_wallet_address | Get wallet address for funding |
Usage Example
You: Send a thank you note to John Doe at 123 Main St, San Francisco, CA 94102
Claude: [calls get_mail_quote] Cost: $1.50 (~0.015 SOL) for domestic US mail
[calls send_mail] Letter sent!
Letter ID: ltr_abc123
Tracking: 9400000000000000000000
Payment: 0.015 SOL (tx: 5j7s...)
Delivery: 3-5 business days
How It Works
Agent composes letter --> MCP validates address --> Solana tx signed
--> Payment sent to merchant --> SolMail verifies on-chain
--> Lob.com prints letter --> USPS delivers --> Tracking returned
Pricing
| Type | Price | SOL (at $100/SOL) |
|---|---|---|
| US Domestic | $1.50 | ~0.015 SOL |
| International | $2.50 | ~0.025 SOL |
| Color printing | +$0.50 | +0.005 SOL |
| Solana tx fee | ~$0.00025 | ~0.0000025 SOL |
Configuration
| Variable | Required | Description |
|---|---|---|
SOLANA_PRIVATE_KEY | Yes | Agent wallet private key (base58) |
SOLANA_NETWORK | No | devnet (default) or mainnet-beta |
SOLMAIL_API_URL | No | API endpoint (default: https://solmail.online/api) |
MERCHANT_WALLET | No | Custom payment destination |
Important: Create a dedicated wallet with limited funds for AI agents. Never use your primary wallet.
Development
npm install && npm run build
npm run dev # Watch mode
npm start # Production
Related Projects
- solana-mcp-server-app -- Solana wallet + DeFi MCP
- coldstar-colosseum -- Air-gapped Solana vault
- ordinals-mcp -- Bitcoin Ordinals MCP server
- cpanel-mcp -- cPanel hosting MCP server
Contributing
- Fork the repository
- Create your feature branch (
git checkout -b feature/my-feature) - Commit your changes
- Open a Pull Request
Links
License
MIT -- Purple Squirrel Media
