How do I install Solmail?

Copy the stdio config for Cursor, Claude Desktop, Claude Code, or VS Code on this page. It uses the publisher's install, not a PlugMCP proxy.

Does Solmail need an API key?

The publisher lists these environment variables: SOLANA_PRIVATE_KEY, SOLANA_NETWORK, SOLMAIL_API_URL, MERCHANT_WALLET.

What transport does Solmail use?

Solmail runs locally over stdio.

When was Solmail last checked?

Last checked 2026-11-09. Send physical mail with Solana cryptocurrency - AI agents can send real letters worldwide

Solmail MCP server

Power your agent

Add this server

The publisher's own command. Not a PlugMCP endpoint.

Add to Cursor Add to VS Code Run on PlugMCP

Host a copy with our keys and logs.

Local command

npx -y [email protected]

Credentials from the publisher

SOLANA_PRIVATE_KEY — Your agent's Solana wallet private key (base58 or JSON array format)
SOLANA_NETWORK — Solana network: devnet for testing, mainnet-beta for production
SOLMAIL_API_URL — SolMail API endpoint
MERCHANT_WALLET — Merchant wallet address for payments

Claude Code has no install link for a local command. Copy the command below and run it in a terminal.

shClaude Code

1SOLANA_PRIVATE_KEY=<secret> SOLANA_NETWORK=<value> SOLMAIL_API_URL=<value> MERCHANT_WALLET=<value> claude mcp add io.github.expertvagabond-solmail -- npx -y solmail-mcp@1.0.2

Run in a terminal.

jsonClaude Desktop

1{2  "mcpServers": {3    "io.github.expertvagabond-solmail": {4      "command": "npx",5      "args": [6        "-y",7        "[email protected]"8      ],9      "env": {10        "SOLANA_PRIVATE_KEY": "<secret>",11        "SOLANA_NETWORK": "<value>",12        "SOLMAIL_API_URL": "<value>",13        "MERCHANT_WALLET": "<value>"14      }15    }16  }17}

claude_desktop_config.json

Local · npmPublisher installStep-by-step: add this in Claude

Remote URL or a command on your machine? How the two installs differ

Run on PlugMCP

Host a copy with our keys and logs.

A new server you create. It is not this listing's official endpoint. Use the publisher install when you want their URL and their credentials.

Launch

Server facts

Local

Transport: stdio
Version: 1.0.2

Tools

No tool list yet. Remote servers get one after the first health check.

FAQ

Questions

: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@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

License

MIT -- Purple Squirrel Media

Solmail

Add this server

Host a copy with our keys and logs.

Server facts

Tools

Questions

How do I install Solmail?

Does Solmail need an API key?

What transport does Solmail use?

When was Solmail last checked?

Documentation

:mailbox_with_mail: solmail-mcp

Install

Features

Tools (4)

Usage Example

How It Works

Pricing

Configuration

Development

Related Projects

Contributing

Links

License