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

Source: Dev.to

How to automate stable‑coin 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:

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

Resources

• GitHub starter pack
• Postman docs

Run the API flow in 10 minutes (Postman)

Import the following files into Postman

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

Then execute the sequence

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

Sample webhook handler (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"));

Recommended minimum table fields

Key takeaways

• No manual transaction‑by‑transaction matching required.
• Deterministic keys prevent duplicate posting.
• The proof endpoint provides auditable evidence for completed orders.
• Keep your existing Web2 backend; simply add a webhook endpoint with an idempotent writer.
• Start with the sandbox environment, then move to production.