SolMail MCP enables AI agents to send real physical mail worldwide using Solana cryptocurrency.
Send physical mail (
send_mail): Compose and send letters/postcards to real addresses in 200+ countries, specifying recipient details, content, color printing, double-sided printing, and mail class (standard/first_class/priority). Returns a letter ID and tracking information on success.Get price quotes (
get_mail_quote): Check the cost of sending mail based on destination country and printing options, returned in both USD and estimated SOL.Check wallet balance (
get_wallet_balance): View the current SOL balance of the configured agent wallet.Get wallet address (
get_wallet_address): Retrieve the public Solana wallet address for funding purposes.Solana payments: Pay for mail using SOL on devnet (testing) or mainnet-beta (production), operating non-custodially with direct wallet control.
Demo/test mode: Use devnet SOL and Lob's test API at zero real cost for development and testing.
Enables AI agents to pay for physical mail services using Solana (SOL) cryptocurrency, providing tools to get quotes, check wallet balances, and manage on-chain transactions.
Facilitates the sending of real physical letters and postcards to addresses worldwide, with fulfillment including delivery via the United States Postal Service (USPS).
Click on "Install Server".
Wait a few minutes for the server to deploy. Once ready, it will show a "Started" state.
In the chat, type
@followed by the MCP server name and your instructions, e.g., "@SolMail MCPsend a physical letter to John Doe at 123 Main St, SF saying 'Thanks for your help!'"
That's it! The server will respond to your query, and you can continue using it as needed.
Here is a step-by-step guide with screenshots.
:mailbox_with_mail: 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@latestAdd 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 price quote for sending mail (country, color options) |
| Send a physical letter with Solana payment |
| Check agent wallet SOL balance |
| 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 daysHow 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 returnedPricing
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 |
| Yes | Agent wallet private key (base58) |
| No |
|
| No | API endpoint (default: |
| 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 # ProductionRelated 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