SolMail
FreeStale (203d)Enables AI agents to send physical letters and postcards to over 200 countries using Solana cryptocurrency for payment. It provides tools for generating mail qu
About
Enables AI agents to send physical letters and postcards to over 200 countries using Solana cryptocurrency for payment. It provides tools for generating mail quotes, managing wallet balances, and automating physical correspondence directly through the Model Context Protocol.
README
npm version License: MIT GitHub stars Solana
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
Install SolMail in Claude Desktop, Claude Code & Cursor
unyly install solmail-mcpInstalls into Claude Desktop, Claude Code, Cursor & VS Code — handles npx, uvx and build-from-source repos for you.
First time? Get the CLI: curl -fsSL https://unyly.org/install | sh
Or configure manually
Run in your terminal:
claude mcp add solmail-mcp --env LOB_API_KEY="" --env MERCHANT_WALLET="" --env SOLANA_NETWORK="" --env SOLANA_PRIVATE_KEY="" --env SOLANA_RPC_URL="" --env SOLMAIL_API_URL="" -- npx -y solmail-mcpStep-by-step: how to install SolMail
FAQ
Is SolMail MCP free?
Yes, SolMail MCP is free — one-click install via Unyly at no cost.
Does SolMail need an API key?
Yes, it requires environment variables: LOB_API_KEY, MERCHANT_WALLET, SOLANA_NETWORK, SOLANA_PRIVATE_KEY, SOLANA_RPC_URL, SOLMAIL_API_URL. Unyly injects them into the config during install.
Is SolMail hosted or self-hosted?
A hosted option is available: Unyly runs the server in the cloud, no local setup required.
How do I install SolMail in Claude Desktop, Claude Code or Cursor?
Open SolMail on unyly.org, pick your client tab (Claude Desktop, Claude Code, Cursor) and press Install — the config is generated automatically, no JSON editing.
Changes
Versions and requested access over time.
- New version published
- New version published
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