THE MINT ENDPOINT

One endpoint, one method. Unpaid requests get a 402 describing what payment is required. Retry with a signed Circle Gateway authorization in the PAYMENT-SIGNATURE header and the mint executes on Arc. Payment comes from the payer's Gateway balance, so it needs a one-time USDC deposit into Gateway first. Retrying the same payment is safe: it never mints twice. No API keys, no accounts, no wallet connect. Payment is the only credential.

> ENDPOINT

POST https://the402s.xyz/mint

Content-Type

application/json

Price

1000000 (1.00 USDC, 6 decimals)

Chain

eip155:5042002 (Arc Testnet)

Asset

USDC · 0x3600…0000

Payment header

PAYMENT-SIGNATURE (x402 v2)

Settlement

Circle Gateway, batched. Payer needs a Gateway USDC balance.

Limit

5 per wallet, counted for both the payer and the recipient

> REQUEST BODY

{
  "to": "0x…"  // required, recipient of the NFT
}

> RESPONSES

402 Payment Required: no PAYMENT-SIGNATURE header sent. The same object is base64 encoded in the PAYMENT-REQUIRED response header.

{
  "x402Version": 2,
  "resource": { "url": "https://the402s.xyz/mint", … },
  "accepts": [{
    "scheme": "exact",
    "network": "eip155:5042002",
    "asset": "0x3600…0000",
    "amount": "1000000",
    "payTo": "0x…",
    "maxTimeoutSeconds": 604900,
    "extra": {
      "name": "GatewayWalletBatched", "version": "1",
      "verifyingContract": "0x0077777d7EBA4688BDeF3E311b846F25870A19B9"
    }
  }],
  "limits": { "perWallet": 5 }
}

200 OK: payment settled, token minted

{
  "success": true,
  "to": "0x…",
  "tokenId": 219,
  "mintTxHash": "0x7f2a…",
  "paymentTxHash": "0x1a9d…",
  "explorer": "https://…/tx/0x7f2a…"
}

400

Missing or malformed recipient address, or invalid JSON

402

No payment sent, or verification or settlement failed. Nothing was charged.

403

wallet_limit: this payer or recipient already has 5. Checked before any money moves.

409

sold_out: all 2,222 minted. Or payment_in_progress: this exact payment is already being processed.

429

rate_limited: too many requests from this address. Slow down.

500

mint_failed: payment settled but the mint failed. Recorded for manual resolution, keep the paymentTxHash.

502

settlement_unknown: the payment service timed out mid settlement. Do not retry. Recorded for manual resolution.

503

facilitator_unavailable: payment service unreachable. Nothing was charged. Retry later.

> CLIENT EXAMPLE

typescript

import { GatewayClient } from "@circle-fin/x402-batching/client";

const gateway = new GatewayClient({ chain: "arcTestnet", privateKey });

// once: move USDC from the wallet into Gateway (1 USDC per mint)
await gateway.deposit("1");

const { data } = await gateway.pay("https://the402s.xyz/mint", {
  method: "POST",
  body: { to: gateway.address },
});

// the 402 round trip is handled for you

> NEXT

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