Connect a wallet-enabled x402 client to Ontario.

The buyer path that actually reaches payment

Free preflight: do this before any wallet code

curl -sS -X POST https://ontarioprotocol.com/api/agent/can-pay \
  -H 'Content-Type: application/json' \
  -d '{
    "endpoint": "https://ontarioprotocol.com/api/agent/pay",
    "agent_policy": "strict",
    "max_usdc": "0.002",
    "verify_live": true
  }'

Continue only when decision is allow. A free result is already enough when the task is browsing, discovery, readiness, or sandbox rehearsal. Payment is for the incremental task-specific answer only.

HTTP buyer example with a local x402 wallet client

This example uses the official x402 client packages. It is intentionally blocked unless the operator explicitly sets ALLOW_X402_PAYMENT=1. The key stays in the local process and is never sent to Ontario.

npm init -y
npm install @x402/fetch @x402/evm viem

ALLOW_X402_PAYMENT=1 \
EVM_PRIVATE_KEY='0xREPLACE_WITH_A_DEDICATED_LIMITED_WALLET_KEY' \
node --input-type=module <<'NODE'
import { x402Client, wrapFetchWithPayment, x402HTTPClient } from "@x402/fetch";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";

const base = "https://ontarioprotocol.com";
const endpoint = `${base}/api/agent/pay`;
const body = {
  query: "What evidence should an agent inspect before paying an x402 endpoint?",
  endpoint: `${base}/api/x402/agent-trust-scan`,
  max_usdc: "0.002",
  agent_policy: "strict"
};

if (process.env.ALLOW_X402_PAYMENT !== "1") {
  throw new Error("Refusing to sign: set ALLOW_X402_PAYMENT=1 after reviewing the quote.");
}
if (!process.env.EVM_PRIVATE_KEY || process.env.EVM_PRIVATE_KEY.includes("REPLACE_")) {
  throw new Error("Set EVM_PRIVATE_KEY only in the local wallet runtime; never commit or send it.");
}

const signer = privateKeyToAccount(process.env.EVM_PRIVATE_KEY);
const client = new x402Client();
registerExactEvmScheme(client, { signer });
const fetchWithPayment = wrapFetchWithPayment(fetch, client);
const response = await fetchWithPayment(endpoint, {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify(body)
});
const payload = await response.json();
const payment = new x402HTTPClient(client)
  .getPaymentSettleResponse((name) => response.headers.get(name));
console.log(JSON.stringify({ http_status: response.status, payload, payment }, null, 2));
NODE

This is an integration example, not a request for Ontario's wallet credentials. Review the live 402, verify the amount and resource, and use a wallet with a strict limit. Ontario does not run this payment as part of the guide.