X402 MCP Server

@privadovpn/x402-mcp

Local stdio MCP server that signs and broadcasts x402 USDC payments (Solana, EVM) to buy PrivadoVPN access.

Security model

This server signs payments locally and never transmits your private key anywhere.

• SOLANA_PRIVATE_KEY and EVM_PRIVATE_KEY are read from local process environment variables. They are used only to sign transactions in-process and are never sent over the network or written to disk by this server.
• The only data that leaves the machine is a signed payment authorization (EVM EIP-3009) or a broadcast transaction signature (Solana), sent to X402_BASE_URL to fulfill a purchase.
• Use a dedicated, low-balance wallet for this server — never point it at a primary or high-balance wallet.
• wallet_status returns configured addresses and network selection only. It never returns private keys or any secret material.
• Credentials returned after a successful purchase are written only to ~/.privado/ on your local machine.

Quick start

npx -y @privadovpn/x402-mcp

Claude Desktop (claude_desktop_config.json):

{
  "mcpServers": {
    "privadovpn-x402-mcp": {
      "command": "npx",
      "args": ["-y", "@privadovpn/x402-mcp"],
      "env": {
        "SOLANA_PRIVATE_KEY": "<your-base58-key>"
      }
    }
  }
}

Claude Code:

claude mcp add privadovpn-x402-mcp -e SOLANA_PRIVATE_KEY=<your-base58-key> -- npx -y @privadovpn/x402-mcp

Cursor (.cursor/mcp.json):

{
  "mcpServers": {
    "privadovpn-x402-mcp": {
      "command": "npx",
      "args": ["-y", "@privadovpn/x402-mcp"],
      "env": {
        "SOLANA_PRIVATE_KEY": "<your-base58-key>"
      }
    }
  }
}

Configuration

Tools

Purchase flow and recovery

Each GET /pay request creates a new invoice on the server. Because of this, buy_vpn must be called exactly once per purchase attempt — calling it again after funds have already been sent creates a second invoice and results in a duplicate charge.

If buy_vpn reports that the on-chain payment succeeded but fulfillment failed (for example, due to a network error when exchanging the payment for credentials), do not call buy_vpn again. Instead call fulfill_payment with the plan, invoice_no, payment_signature, and settlement_tx values from the error. This exchanges the already-completed payment for credentials without creating a new invoice or sending additional funds.

buy_vpn and sign_and_pay both accept a dry_run flag that performs balance checks without broadcasting a transaction. Note that a dry run still creates a real invoice on the server; it does not need to be followed by a real purchase, but it should not be repeated for the same purchase attempt.

How it works

sequenceDiagram
    participant Agent
    participant MCP as Local MCP (this server)
    participant Backend as x402.privadovpn.com

    Agent->>MCP: buy_vpn(plan, country)
    MCP->>Backend: GET /pay?plan=...
    Backend-->>MCP: 402 Payment Required + quote (accepts[])
    MCP->>MCP: sign payment locally (private key never leaves process)
    MCP->>Backend: broadcast transaction on-chain
    Backend-->>MCP: transaction confirmed
    MCP->>Backend: GET /pay (PAYMENT-SIGNATURE, X-Settlement-Transaction)
    Backend-->>MCP: VPN credentials
    MCP-->>Agent: credentials + settlement_tx + credentials_path

Supported networks: Solana (SPL USDC transfer) and EVM (EIP-3009 transferWithAuthorization USDC).

Server-side discovery

• Catalog and payment discovery: https://x402.privadovpn.com/.well-known/x402-payment
• Agent-readable service description: https://x402.privadovpn.com/llms.txt
• Remote MCP (catalog/docs only, no wallet access): https://x402.privadovpn.com/mcp

Development

git clone git@github.com:privadovpn/x402-mcp.git
cd x402-mcp
npm install
npm run build
npm test

Run with the MCP Inspector:

npx @modelcontextprotocol/inspector node dist/index.js

License

MIT. See LICENSE.

mcp-name: io.github.privadovpn/x402-mcp