Uniple x402 Agent Skill

Skill + MCP server for AI agents buying products exposed through Uniple's x402 catalog API. It is intended for KOVA, Codex, Claude Desktop, and other MCP-capable agent clients.

This is separate from jpyc-ec-purchase: JPYC EC uses x402 v2, POST /api/v1/checkout, and PAYMENT-SIGNATURE. Uniple currently uses x402 v1, catalog/payment URLs, and X-PAYMENT.

What It Supports

• Read-only catalog discovery:
  • GET https://uniple.io/api/x402/shop/eccube/products?merchantSiteId=...
• Quote / payment challenge:
  • GET paymentUrl with quantity and shipping* query params
  • Reads 402 + decoded paymentRequired
• Optional purchase:
  • Signs JPYC EIP-3009 TransferWithAuthorization
  • Calls the same payment URL with X-PAYMENT
  • Returns Uniple's paid response and webhook status

Safety

Use quote_product first. It never signs or sends funds.

purchase_product requires:

• BUYER_PRIVATE_KEY env var
• max_amount_atomic budget cap
• matching quote amount within that cap

Do not configure a funded private key unless you intend to allow the MCP server to purchase.

Local Build

cd uniple-x402-agent-skill
npm install
npm run build
npm test

MCP Config Example

{
  "mcpServers": {
    "uniple-x402-purchase": {
      "command": "node",
      "args": [
        "/absolute/path/uniple-x402-agent-skill/mcp-servers/uniple-x402-purchase/dist/bin.js"
      ],
      "env": {
        "UNIPLE_API_URL": "https://uniple.io",
        "BUYER_PRIVATE_KEY": "0x..."
      }
    }
  }
}

Omit BUYER_PRIVATE_KEY if you only want catalog and quote tools.

EC-CUBE4 Smoke Target

Catalog:

https://uniple.io/api/x402/shop/eccube/products?merchantSiteId=eccube4.uniple.io

Typical 55 JPYC item quote with the current EC-CUBE4 shipping settings:

• product subtotal: 55 JPYC
• shipping: 150 JPYC
• total: 205 JPYC
• network: eip155:137
• asset: JPYC Polygon 0xE7C3...3c29