X402 A2a Agent Card Signature Confidence Lens

# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i -X POST 'https://api.blockchainmoneymap.com/api/x402/x402-a2a-agent-card-signature-confidence-lens' \
  -H 'content-type: application/json' \
  --data-raw '{"facts":{"agentCardJson":{"issuedAt":"2026-07-22","provider":"Acme Agent Labs","signatures":["issuer-signature"],"version":"1.0.0"},"issuerLabel":"Acme Agent Labs","signatureFields":{"algorithm":"declared","issuedAt":"2026-07-22","issuer":"Acme Agent Labs","keyId":"public-key-1"},"sourceLabel":"public agent card excerpt","version":"v1.0.0"},"mode":"check"}'

# x402 v2 sends the challenge base64-encoded in the PAYMENT-REQUIRED header (v1 sends it in the body).
# To read the header:
curl -sS -g -o /dev/null -D - -X POST 'https://api.blockchainmoneymap.com/api/x402/x402-a2a-agent-card-signature-confidence-lens' \
  -H 'content-type: application/json' \
  --data-raw '{"facts":{"agentCardJson":{"issuedAt":"2026-07-22","provider":"Acme Agent Labs","signatures":["issuer-signature"],"version":"1.0.0"},"issuerLabel":"Acme Agent Labs","signatureFields":{"algorithm":"declared","issuedAt":"2026-07-22","issuer":"Acme Agent Labs","keyId":"public-key-1"},"sourceLabel":"public agent card excerpt","version":"v1.0.0"},"mode":"check"}' \
  | grep -i '^payment-required:' | cut -d' ' -f2 | tr -d '\r' | base64 --decode

// npm i @x402/fetch @x402/evm viem
import { wrapFetchWithPayment, x402Client } from "@x402/fetch";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";

// Pays at most $0.01 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.01" });
registerExactEvmScheme(client, { signer: privateKeyToAccount(process.env.EVM_PRIVATE_KEY) });
const pay = wrapFetchWithPayment(fetch, client);

// Not sure it's safe to pay? ToolVet checks it first for $0.005. Pay for that from a separate
// client: this one is capped at $0.01 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fapi.blockchainmoneymap.com%2Fapi%2Fx402%2Fx402-a2a-agent-card-signature-confidence-lens&method=POST
const res = await pay("https://api.blockchainmoneymap.com/api/x402/x402-a2a-agent-card-signature-confidence-lens", {
  method: "POST",
  headers: { "content-type": "application/json" },
  body: JSON.stringify({
    "facts": {
      "agentCardJson": {
        "issuedAt": "2026-07-22",
        "provider": "Acme Agent Labs",
        "signatures": [
          "issuer-signature"
        ],
        "version": "1.0.0"
      },
      "issuerLabel": "Acme Agent Labs",
      "signatureFields": {
        "algorithm": "declared",
        "issuedAt": "2026-07-22",
        "issuer": "Acme Agent Labs",
        "keyId": "public-key-1"
      },
      "sourceLabel": "public agent card excerpt",
      "version": "v1.0.0"
    },
    "mode": "check"
  }),
});
console.log(res.status, await res.text());

# pip install "x402[requests,evm]"
import os
from eth_account import Account
from x402 import x402ClientSync
from x402.http.clients import x402_requests
from x402.mechanisms.evm import EthAccountSigner
from x402.mechanisms.evm.exact.register import register_exact_evm_client

# Pays at most $0.01 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.01"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.post(
        "https://api.blockchainmoneymap.com/api/x402/x402-a2a-agent-card-signature-confidence-lens",
        json={
            "facts": {
                "agentCardJson": {
                    "issuedAt": "2026-07-22",
                    "provider": "Acme Agent Labs",
                    "signatures": [
                        "issuer-signature",
                    ],
                    "version": "1.0.0",
                },
                "issuerLabel": "Acme Agent Labs",
                "signatureFields": {
                    "algorithm": "declared",
                    "issuedAt": "2026-07-22",
                    "issuer": "Acme Agent Labs",
                    "keyId": "public-key-1",
                },
                "sourceLabel": "public agent card excerpt",
                "version": "v1.0.0",
            },
            "mode": "check",
        },
    )
    print(res.status_code, res.text)