Genesis402 (x402 pay Per Call)

360 pay-per-call APIs for AI agents over x402 and MPP.
USDC on Base · $0.001 to $0.25 a call · no API key · no account.
Every response names its sources and carries an evidence hash. A paid call that is not delivered is credited automatically.

Rail · Catalog · Live status · Receipts · UnyKorn

Connect in 30 seconds

Hosted MCP (nothing to install)

Add this remote to Claude, Cursor, VS Code or any MCP client that speaks streamable HTTP:

https://twin.unykorn.org/mcp

The hosted server holds no keys. Free tools (catalog, receipt) work immediately. Paid tools return the exact price quote, or run with a payment_signature you produce with your own wallet.

Local MCP (pays for you, within a cap you set)

{
  "mcpServers": {
    "genesis402": {
      "command": "npx",
      "args": ["-y", "genesis402-mcp"],
      "env": {
        "GENESIS402_LIVE": "1",
        "GENESIS402_PAYER_KEY": "0x<private key of a wallet holding a little USDC on Base>",
        "GENESIS402_MAX_USD": "0.25"
      }
    }
  }
}

Without GENESIS402_LIVE=1 the server is quote-only: it shows the price and signs nothing. The rail sets the price; the client decides whether to accept it. Use a dedicated wallet with a small balance.

Plain HTTP, any language

x402

GET https://twin.unykorn.org/price/bitcoin
→ 402, header payment-required: <base64 x402 v2 challenge>
sign the USDC authorization (EIP-3009) for the quoted amount, retry with X-PAYMENT
→ 200 + result + receipt id

MPP (the Payment HTTP auth scheme)

GET https://twin.unykorn.org/price/bitcoin
→ 402, header WWW-Authenticate: Payment id="…", method="usdc", intent="charge", request="…"
sign the same EIP-3009 authorization, retry with  Authorization: Payment <base64url credential>
→ 200 + result + Payment-Receipt header

Both dialects quote the same price to the same address in the same token. MPP discovery is the standard /openapi.json with x-payment-info on every operation.

Free before you pay: POST /__validate checks your parameters with the same validator the paid path uses, so a bad request is never charged.

MCP tools

Live prices come from the rail's manifest; genesis402_catalog shows them. Every paid tool returns the receipt id and evidence hash with the result.

What is on the rail (360 endpoints)

Full list with schemas and live examples: catalog, /.well-known/x402, /openapi.json.

Guarantees

• Validate before pay. Bad input returns 400 with "nothing was charged".
• Sources on every answer. Each response lists the upstream it read and an evidence_hash. A failed upstream is an error, never a silent zero.
• Make-good. A paid call that is not delivered is credited to the payer automatically; the guardian reconciles every settlement on-chain within 48 hours.
• Public status. twin.unykorn.org/status is the guardian's own report, refreshed every 5 minutes.
• Identity. ERC-8004 agent 95721 on Base; A2A card at the rail root.

Payment rails

x402 v2 exact scheme and MPP usdc/charge (EIP-3009 authorization), on USDC on Base (primary) and Polygon. Solana USDC via facilitator settlement. XRP and USDC on XRPL and Stellar are pay-first, with the payment bound to the challenge nonce. The 402 response lists exactly which lanes are payable right now.

Repo layout

• mcp/ — the MCP server (npx genesis402-mcp; genesis402-mcp-http for hosted mode), server.json for the MCP Registry, smoke.mjs (13 read-only checks against the live rail).
• quickstart/ — Node and Python payers for Base, XRPL and Stellar.
• assets/ — brand banner and icon.

Built by UnyKorn LLC · Wyoming
_{MIT license. Risk and sanctions outputs are heuristic signals from public data, not KYC or a compliance determination. Not financial, legal or tax advice.}