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).

1. Click on "Install Server".

2. Wait a few minutes for the server to deploy. Once ready, it will show a "Started" state.

3. In the chat, type @ followed by the MCP server name and your instructions, e.g., "@SolMail MCP send 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.

npx solmail-mcp@latest

{
 "mcpServers": {
 "solmail": {
 "command": "npx",
 "args": ["-y", "solmail-mcp"],
 "env": {
 "SOLANA_NETWORK": "devnet",
 "SOLANA_PRIVATE_KEY": "your_base58_private_key"
 }
 }
 }
}

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

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

npm install && npm run build
npm run dev # Watch mode
npm start # Production