Paystack Webhooks

Paystack Webhooks

Webhooks let Paystack push real-time event notifications to your server. They are the recommended way to confirm payment status — more reliable than client-side callbacks or polling.

Depends on: paystack-setup for environment configuration.

How Webhooks Work

Customer pays → Paystack processes → Paystack POSTs event JSON to your webhook URL
                                   → Your server validates signature
                                   → Returns 200 OK immediately
                                   → Then processes the event asynchronously

Endpoints

Your webhook URL is a POST endpoint you create on your server. Register it on the Paystack Dashboard under Settings → API Keys & Webhooks.

Signature Validation

Every webhook request includes an x-paystack-signature header containing an HMAC SHA512 hash of the request body, signed with your secret key. Always validate this before processing.

Next.js App Router (Route Handler)

// app/api/webhooks/paystack/route.ts
import crypto from "crypto";
import { NextRequest, NextResponse } from "next/server";

export async function POST(req: NextRequest) {
  const body = await req.text();
  const signature = req.headers.get("x-paystack-signature");
  
  const hash = crypto
    .createHmac("sha512", process.env.PAYSTACK_SECRET_KEY!)
    .update(body)
    .digest("hex");

  if (hash !== signature) {
    return NextResponse.json({ error: "Invalid signature" }, { status: 401 });
  }

  // Return 200 immediately — process event asynchronously
  const event = JSON.parse(body);

  // Handle event based on type
  switch (event.event) {
    case "charge.success":
      await handleChargeSuccess(event.data);
      break;
    case "transfer.success":
      await handleTransferSuccess(event.data);
      break;
    case "transfer.failed":
      await handleTransferFailed(event.data);
      break;
    // ... handle other events
  }

  return NextResponse.json({ received: true }, { status: 200 });
}

async function handleChargeSuccess(data: any) {
  const { reference, amount, customer, metadata } = data;
  // Verify the transaction server-side as an extra check
  // Update your database, fulfill the order, etc.
}

async function handleTransferSuccess(data: any) {
  const { reference, amount, recipient } = data;
  // Mark transfer as completed in your database
}

async function handleTransferFailed(data: any) {
  const { reference, amount } = data;
  // Mark transfer as failed, notify admin, retry if needed
}

Express.js

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

const app = express();
app.use(express.json());

app.post("/webhooks/paystack", (req, res) => {
  const hash = crypto
    .createHmac("sha512", process.env.PAYSTACK_SECRET_KEY!)
    .update(JSON.stringify(req.body))
    .digest("hex");

  if (hash !== req.headers["x-paystack-signature"]) {
    return res.status(401).send("Invalid signature");
  }

  // Return 200 immediately
  res.sendStatus(200);

  // Process event asynchronously
  const event = req.body;
  processEvent(event).catch(console.error);
});

IP Whitelisting

As an additional security layer, only allow requests from Paystack's IP addresses:

52.31.139.75
52.49.173.169
52.214.14.220

These IPs apply to both test and live environments.

const PAYSTACK_IPS = ["52.31.139.75", "52.49.173.169", "52.214.14.220"];

function isPaystackIP(ip: string): boolean {
  // Handle x-forwarded-for if behind a proxy/load balancer
  const clientIP = ip.split(",")[0].trim();
  return PAYSTACK_IPS.includes(clientIP);
}

Retry Policy

If your webhook endpoint doesn't return a 200 OK status, Paystack retries:

Request timeout is 30 seconds in test mode. Return 200 OK immediately and process events asynchronously to avoid timeouts.

Idempotency

Webhook events may be sent more than once. Make your handler idempotent:

async function handleChargeSuccess(data: any) {
  const { reference } = data;

  // Check if already processed
  const existing = await db.transaction.findUnique({ where: { reference } });
  if (existing?.status === "completed") {
    return; // Already processed, skip
  }

  // Process and mark as completed atomically
  await db.transaction.upsert({
    where: { reference },
    update: { status: "completed", paidAt: new Date() },
    create: { reference, status: "completed", amount: data.amount, paidAt: new Date() },
  });
}

Supported Event Types

Event Payload Structure

Every webhook event follows this structure:

{
  "event": "charge.success",
  "data": {
    "id": 4099260516,
    "domain": "live",
    "status": "success",
    "reference": "re4lyvq3s3",
    "amount": 50000,
    "currency": "NGN",
    "channel": "card",
    "customer": {
      "id": 82796315,
      "email": "customer@email.com",
      "customer_code": "CUS_xxxxx"
    },
    "authorization": {
      "authorization_code": "AUTH_xxxxx",
      "card_type": "visa",
      "last4": "4081",
      "reusable": true
    },
    "metadata": {}
  }
}

Go-Live Checklist

1. Add the webhook URL on your Paystack dashboard (Settings → API Keys & Webhooks)
2. Ensure the URL is publicly accessible (localhost won't receive events)
3. If using .htaccess, add a trailing / to the URL
4. Validate signature on every request using x-paystack-signature
5. Return 200 OK immediately before processing long-running tasks
6. Make handlers idempotent — events can be sent more than once
7. Test with Paystack's test mode before going live