Pay for code402.dev
Two ways: card (pre-paid credits, no crypto) or x402 (USDC on Base, for agents). Cheapest tool right now: iban-check at $0.005 (live dynamic quote).
Pay by card — no wallet, no crypto
Buy pre-paid credits and call any of the 82 tools with an API key. Credits decrement at the flat live price (watch /health).
ck_live_... Bearer key for institutional AP/treasury fleets, multi-corridor priority routing, and XDR-1 audit bundles.
£399 ($499) — Enterprise Corridor Guard (75,000 Live Verifications + 12-Registry & 30-Ccy ECB FX) →
Instant ck_live_... key for ERP webhooks, ISO 20022 repair, 3-way reconciliation, and continuous batch audits.
$250 — Done-For-You Batch Validation Run (Paid on Delivery) · or £79 ($99) Self-Serve 2,000-Row Batch Audit →
Full field mapping + reproducible JSON exception report on your supplier CSV / pain.001 XML, or run self-serve at /batch-cure.
£39 ($49) — Operator Quota Key (5,000 Live Statutory Verifications) →
Standard prepaid ck_live_... key across all 55 tools + canonical XDR-1 signed receipts.
Pay via PayPal (PYUSD) or Coinbase (USDC) — Direct Transfer → Instant API Key
No EIP-3009 off-chain signature needed. Send any amount from PayPal, Venmo, Coinbase, MetaMask, or Phantom directly to our non-custodial treasury, then paste the transaction hash below to mint your ck_live_tx_... Bearer token immediately ($1 = 300 calls, $4 = 1,250 calls, $16 = 5,500 calls):
- Coinbase (USDC — $0 fee on Base): Send USDC on Base, Arbitrum, Optimism, Polygon, or Ethereum to
0xc59c85e661d34084a7769f955d17fd38254a6235 - PayPal / Venmo (PYUSD — 1:1 PayPal USD): Send PYUSD on Arbitrum (
0x46850aD61C2B7d64d08c9C754F45254596696984) or Ethereum (0x6c3ea9036406852006290770BEdFcAbA0e23A0e8) to0xc59c85e661d34084a7769f955d17fd38254a6235 - Solana (PYUSD or USDC — sub-cent fee): Send PYUSD or USDC on Solana Mainnet to
23bpARXxQYw5xVK5Mp6HwwqsymFckZdFgnVQx49N1n2B
x402 · USDC on Base (for agents)
Any x402 buyer pays automatically. Get USDC on Base once, then each call auto-settles with a signed receipt.
0 · Get USDC on Base (one time)
Fund with Coinbase → Coinbase's hosted Onramp, pre-bound to your wallet + USDC on Base. Non-custodial: funds deliver straight from Coinbase to your wallet. No signup.
On any major exchange: buy USDC, then withdraw to your wallet choosing the Base network in the network picker. Already on another chain? Bridge USDC to Base with any standard bridge. You need no ETH for gas — settlement is gas-sponsored. A few dollars of USDC covers thousands of calls.
1 · Official SDK (recommended)
npm i @x402/fetch @x402/evm viem
import { wrapFetchWithPayment } from "@x402/fetch";
import { x402Client } from "@x402/core/client";
import { ExactEvmScheme } from "@x402/evm/exact/client";
const client = new x402Client();
client.register("eip155:*", new ExactEvmScheme(signer)); // funded wallet
const fetch2 = wrapFetchWithPayment(fetch, client);
await fetch2("https://api.code402.dev/v1/tools/iban-check/call", { method:"POST",
headers:{ "content-type":"application/json" },
body: JSON.stringify({ input:{ iban:"GB82 WEST 1234 5698 7654 32" } }) });
// 402 -> auto-sign -> auto-settle (USDC on Base) -> 200 + signed receipt
2 · Any MCP client
POST https://api.code402.dev/mcp { "method":"tools/call", "params":{ "name":"iban_check", ... } }
// the 402 challenge comes back inside the tool error — sign, retry with X-PAYMENT
3 · Verify what you paid for
every 200 carries receipt: { v:"XDR-1", input_hash, output_hash, amount, tx, signer }
recover the signer from https://api.code402.dev/.well-known/mcp.json receipt_signing_address
Prices are flat — no demand surge. A gas-spike guard can raise the floor to cover settlement cost. Live quotes: GET /health. Free tier: first 5 calls/day.