x402 Payment Gateway MCP Server 💰

MCP Server that enables micropayments between AI agents using USDC on Solana. Based on the x402 protocol (HTTP 402 Payment Required).

What is x402?

x402 is a protocol that lets AI agents pay for services automatically. When an agent calls a premium tool, it gets a "402 Payment Required" response with payment instructions. The agent pays via blockchain, then gets access.

Features

• Payment Requests — Create x402-compatible payment requests for any tool
• On-Chain Verification — Verify USDC payments directly on Solana
• Tool Pricing — Set per-call prices for individual tools
• Revenue Tracking — Dashboard with total revenue, per-tool breakdown
• Payment History — Full audit trail of all transactions

Installation

pip install x402-mcp-server

Configuration

Set your merchant wallet in .env:

MERCHANT_WALLET=YourSolanaWalletAddress
SOLANA_RPC_URL=https://api.mainnet-beta.solana.com

Usage with Claude Code

{
  "mcpServers": {
    "x402": {
      "command": "uvx",
      "args": ["x402-mcp-server"],
      "env": {
        "MERCHANT_WALLET": "YourSolanaWalletAddress"
      }
    }
  }
}

Tools

Flow

Agent A                    x402 Gateway                 Agent B (Service)
   |                           |                             |
   |-- "Use premium tool" ---->|                             |
   |                           |-- 402 Payment Required ---->|
   |<-- Payment instructions --|                             |
   |                           |                             |
   |-- USDC payment on-chain ->|                             |
   |                           |-- verify_payment ---------->|
   |                           |<-- verified ----------------|
   |<-- Access granted --------|                             |

More MCP Servers by AiAgentKarl

→ Full catalog (40+ servers)

License

MIT