How to automate stablecoin payment reconciliation with webhooks (developer runbook)

How to automate stablecoin payment reconciliation with Webhooks + deterministic IDs

If your team already has a Web2 backend and wants to avoid manual crypto reconciliation, here is a practical flow:

• Create checkout (payment link)
• Receive webhook events (payment.created, payment.confirmed, payment.rejected)
• Pull order proof for audit
• Write deterministic ledger keys in your internal DB

Run-ready assets

• GitHub starter pack: https://github.com/caria-wei/nuvo-verify-developer-inbound
• Postman docs: https://caria-w-6623992.postman.co/documentation/53056051-99c386d3-9da5-4763-abfa-533043c33d40

1) Run the API flow in 10 minutes (Postman)

Import:

• NUVO-Verify-Developer-Inbound.postman_collection.json
• NUVO-Verify-Sandbox.postman_environment.json

Then run:

1. Merchant Login
2. Create Payment Link
3. Create Webhook
4. Send Test Webhook
5. Get Order Proof

2) Webhook receiver (Node.js)

import express from "express";
import crypto from "crypto";

const app = express();
app.use(express.raw({ type: "*/*" }));

const WEBHOOK_SECRET = process.env.NUVO_WEBHOOK_SECRET;

function verifySignature(rawBody, signatureHeader, secret) {
  const expected = "sha256=" + crypto.createHmac("sha256", secret).update(rawBody).digest("hex");
  const a = Buffer.from(signatureHeader || "");
  const b = Buffer.from(expected);
  return a.length === b.length && crypto.timingSafeEqual(a, b);
}

app.post("/webhooks/nuvo", (req, res) => {
  const sig = req.header("x-nuvo-signature") || req.header("x-signature") || "";
  if (!verifySignature(req.body, sig, WEBHOOK_SECRET)) {
    return res.status(401).json({ ok: false, error: "invalid signature" });
  }

  const payload = JSON.parse(req.body.toString("utf8"));
  const ledgerKey = `${payload?.data?.orderId}:${payload?.data?.tokenSymbol}:${payload?.event}`;

  // upsert to your internal ledger table
  // upsertLedger({ ledgerKey, payload });

  return res.json({ ok: true });
});

app.listen(8787, () => console.log("listening on :8787"));

3) Event-to-ledger mapping

Recommended minimum table fields:

• ledger_key (unique)
• order_id
• event_type
• token_symbol
• amount
• tx_hash
• traffic_light
• received_at
• raw_payload_json

4) Why this reduces ops cost

• No manual transaction-by-transaction matching
• Deterministic keys avoid duplicate posting
• Proof endpoint provides auditable evidence for completed orders

5) Next step

• Keep your current Web2 backend
• Add webhook endpoint + idempotent writer
• Start with sandbox, then move to production environment