Developer reference

# 1. Unpaid request -> HTTP 402 with the payment requirements
curl -i -X POST https://<your-host>/api/verify \
  -H 'content-type: application/json' \
  -d '{"url":"https://destination-to-check.example"}'

# Response: HTTP/1.1 402 Payment Required
#   PAYMENT-REQUIRED: <base64 payment requirements>
#   { "error": "payment_required", "price": "$0.03", "asset": "USDC", ... }

# 2. Re-send the same request with the signed payment
curl -i -X POST https://<your-host>/api/verify \
  -H 'content-type: application/json' \
  -H "PAYMENT-SIGNATURE: $PAYMENT_SIGNATURE" \
  -d '{"url":"https://destination-to-check.example"}'

# Response: HTTP/1.1 200 OK
#   PAYMENT-RESPONSE: <base64 settlement response>

import { x402Client } from "@x402/core/client";
import { x402HTTPClient } from "@x402/core/http";
import { ExactAvmScheme } from "@x402/avm/exact/client";

// signer: { address, signTransactions } — any Algorand wallet signer
const core = new x402Client().register("algorand:*", new ExactAvmScheme(signer));
const client = new x402HTTPClient(core);

const endpoint = "https://<your-host>/api/verify";
const body = JSON.stringify({ url: "https://destination-to-check.example" });
const headers = { "content-type": "application/json" };

// 1. Ask -> 402
const unpaid = await fetch(endpoint, { method: "POST", headers, body });
const required = client.getPaymentRequiredResponse(
  (name) => unpaid.headers.get(name),
  await unpaid.json(),
);

// 2. Sign the USDC payment (ASA 10458941 on algorand:<caip2>)
const payload = await client.createPaymentPayload(required);

// 3. Retry with the payment -> verification runs, then settles
const paid = await fetch(endpoint, {
  method: "POST",
  headers: { ...headers, ...client.encodePaymentSignatureHeader(payload) },
  body,
});

const result = await paid.json();
const settlement = client.getPaymentSettleResponse((n) => paid.headers.get(n));
console.log(result.trust_score, result.interaction_recommendation, settlement.transaction);

{
  "service": "AgentTrust Verify",
  "status": "verified",
  "target": "https://destination-to-check.example",
  "risk_level": "LOW",          // LOW 80-100 | MEDIUM 60-79 | HIGH 0-59
  "trust_score": 90,
  "confidence": 0.92,           // completed checks / total checks
  "interaction_recommendation": "PROCEED_WITH_NORMAL_CAUTION", // | REVIEW | AVOID
  "checks": [{ "id": "https", "label": "HTTPS", "status": "pass", "detail": "..." }],
  "deductions": [{ "reason": "Punycode hostname", "points": 10 }],
  "evidence": ["HTTPS is enabled."],
  "limitations": ["This score evaluates observable technical URL/domain signals and is not proof of identity, legitimacy or complete safety."],
  "redirect_chain": ["https://destination-to-check.example"],
  "checked_at": "2026-01-01T00:00:00.000Z",
  "payment": {
    "settled": true,
    "network": "algorand:<caip2>",
    "asset": "USDC",
    "asset_id": 10458941,
    "price": "0.03",
    "payTo": "<payTo address>",
    "facilitator": "GoPlausible",
    "tag": "x402-global-challenge",
    "transaction": "<algorand transaction id>",
    "payer": "<payer address>"
  }
}