#Merchant verification

You received a PayPal payment whose capture invoice_id starts with AGPOI-. Verify the receipt before fulfilling. The verifier has zero runtime dependencies and never contacts AgentGuard.

#1. Pin the issuer key set

Fetch it once over HTTPS and keep it. Re-fetch when a new kid appears.

curl -sf https://agentguard-orcin.vercel.app/.well-known/agentguard-keys -o agentguard-keys.json

#2. Verify

npx -p @agentguard-dev/intent-verifier intent-verify receipt.json \
  --issuer-keys agentguard-keys.json --payee you@shop.example \
  --origin https://agentguard-orcin.vercel.app --require-timestamp --require-anchor

Exit code 0 means every check passed, 1 a check failed, 2 usage or input error. Add --json for machine-readable output.

Add --paypal to re-fetch the order and capture from PayPal with your own credentials and confirm the amount and the AGPOI-<receipt_id> invoice id:

PAYPAL_CLIENT_ID=… PAYPAL_CLIENT_SECRET=… PAYPAL_API_BASE=https://api-m.sandbox.paypal.com \
  npx -p @agentguard-dev/intent-verifier intent-verify receipt.json --issuer-keys agentguard-keys.json --paypal

#In code

import { readFileSync } from "node:fs";
import { verifyReceipt } from "@agentguard-dev/intent-verifier";

const envelope = JSON.parse(readFileSync("receipt.json", "utf8"));
const issuerKeys = JSON.parse(readFileSync("agentguard-keys.json", "utf8"));
const r = await verifyReceipt(envelope, { issuerKeys,
  expectedOrigins: ["https://agentguard-orcin.vercel.app"], requireTimestamp: true, requireAnchor: true });
if (!r.ok || !r.trusted_issuer) throw new Error(r.checks.filter(c => !c.pass).map(c => `${c.check}: ${c.detail}`).join("\n"));
console.log("verified", r.receipt_id);

Add expectedPayee: ["you@shop.example"] (an array of merchant ids or emails) in production. r.ok means every check passed; r.trusted_issuer means the signature verified under a pinned key.

#Checks performed

Issuer signature and key status · passkey assertion over the mandate (challenge, origin, RP ID hash, UP/UV flags, ES256/EdDSA/RS256 signature) · order digest and order against mandate (currency, limits, payee, SKUs, categories, quantities) · decision binding · time window · capture status · approval passkey signature · enrollment provenance · RFC 3161 timestamp · audit-anchor inclusion and cumulative spend · AP2 derivation.