Genesis402 by UnyKorn (x402 pay-per-call) MCP server

Genesis402 agent kit

Everything an outside developer needs to call and pay for the Genesis402 rail (https://twin.unykorn.org) from an agent.

Payment: x402 v2. USDC on Base, Polygon or Solana (facilitator-settled), USDC on Stellar or XRP on XRPL (pay-first, present the tx hash).

1. MCP server (Claude, Cursor, any MCP client)

{
  "mcpServers": {
    "genesis402": {
      "command": "node",
      "args": ["/path/to/genesis402-agent-kit/mcp/index.mjs"],
      "env": {
        "GENESIS402_LIVE": "0",
        "GENESIS402_PAYER_KEY": "",
        "GENESIS402_MAX_USD": "0.25"
      }
    }
  }
}

Once published to npm, the args become "command": "npx", "args": ["-y", "genesis402-mcp"].

• Default is quote only: paid tools return the price and what you get; nothing is signed.
• Set GENESIS402LIVE=1 and GENESIS402PAYER_KEY (a Base wallet holding a little USDC, no ETH needed) to pay.
• Any quote above GENESIS402MAXUSD is refused.

Tools: genesis402catalog (free), genesis402receipt (free), genesis402risk, genesis402prove, genesis402genesissim, genesis402walletops, genesis402rwascreen, genesis402_llm.

2. Quickstart scripts

cd quickstart && npm install
node buy.mjs risk '{"address":"0x4ed4E862860beD51a9570b96d89aF5E1B0Efefed"}'          # quote
PAYER_KEY=0x... LIVE=1 node buy.mjs genesis-sim '{"n":20,"epochs":20}'                # $0.25 USDC on Base
XRPL_SEED=s... LIVE=1 RAIL=xrpl node buy.mjs genesis-sim '{"n":20,"epochs":20}'       # 0.05 XRP on XRPL

pip install "x402[httpx,evm]" eth-account xrpl-py
python buy.py genesis-sim '{"n":20,"epochs":20}'
PAYER_KEY=0x... LIVE=1 python buy.py genesis-sim '{"n":20,"epochs":20}'

Flow: POST without payment -> 402 with PAYMENT-REQUIRED (base64 JSON) -> sign EIP-3009 transferWithAuthorization (Base) or send the XRPL payment -> retry with PAYMENT-SIGNATURE / X-PAYMENT -> 200 with result and a receipt id (/receipts/{id}).

Failed settlement never charges: the rail answers 402 settlement_failed and states that no funds moved.