Add to your Website

You can integrate in two ways: a one-line drop-in script (easiest), or a server-side API call (most flexible).

Option A — Drop-in script

Add a single script tag and any element with data-fastpayglobal becomes a checkout button.

html

<!-- 1. Include the script -->
<script src="https://fastpayglobal.app/pay.js" defer></script>

<!-- 2. Add a button anywhere on your page -->
<button data-fastpayglobal
  data-public-key="pk_live_xxxxxxxxxxxx"
  data-amount="500"
  data-currency="BDT"
  data-order-id="ORDER-12345"
  data-customer-name="John Doe"
  data-customer-email="john@example.com">
  Pay ৳500
</button>

Programmatic usage:

html

<script src="https://fastpayglobal.app/pay.js" defer></script>
<script>
  document.getElementById("buy").onclick = () => {
    FastPay Global.checkout({
      publicKey: "pk_live_xxxxxxxxxxxx",
      amount: 500,
      currency: "BDT",
      orderId: "ORDER-12345",
      customer: { name: "John", email: "john@example.com" },
      mode: "redirect", // or omit for popup
    });
  };
</script>

Option B — Server-side API

Call our API from your backend, then redirect the customer to the returned paymentUrl.

cURL

curl -X POST https://fastpayglobal.app/api/public/create-payment \
  -H "content-type: application/json" \
  -H "x-public-key: pk_live_xxxxxxxxxxxx" \
  -d '{
    "amount": 500,
    "currency": "BDT",
    "orderId": "ORDER-12345",
    "customer": { "name": "John", "email": "john@example.com" }
  }'

Node.js

// Node.js (server-side)
const res = await fetch("https://fastpayglobal.app/api/public/create-payment", {
  method: "POST",
  headers: {
    "content-type": "application/json",
    "x-public-key": process.env.FASTPAYGLOBAL_PUBLIC_KEY,
  },
  body: JSON.stringify({
    amount: 500,
    currency: "BDT",
    orderId: "ORDER-12345",
    customer: { name: "John", email: "john@example.com" },
  }),
});
const { paymentId, paymentUrl } = await res.json();

// Redirect the customer
return Response.redirect(paymentUrl, 302);

PHP

<?php
$ch = curl_init("https://fastpayglobal.app/api/public/create-payment");
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, [
  "Content-Type: application/json",
  "X-Public-Key: " . getenv("FASTPAYGLOBAL_PUBLIC_KEY"),
]);
curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode([
  "amount" => 500,
  "currency" => "BDT",
  "orderId" => "ORDER-12345",
]));
$response = json_decode(curl_exec($ch), true);
header("Location: " . $response["paymentUrl"]);

Verify the webhook

When the customer pays, we POST a signed webhook to your webhook_url. Verify the signature with your brand's webhook secret.

Express

// Verify FastPay Global webhook signature
import { createHmac, timingSafeEqual } from "node:crypto";

app.post("/webhooks/fastpayglobal", express.raw({ type: "*/*" }), (req, res) => {
  const signature = req.header("x-fastpayglobal-signature") || "";
  const expected = createHmac("sha256", process.env.FASTPAYGLOBAL_WEBHOOK_SECRET)
    .update(req.body) // raw body
    .digest("hex");

  const ok = signature.length === expected.length &&
    timingSafeEqual(Buffer.from(signature), Buffer.from(expected));
  if (!ok) return res.status(401).send("invalid signature");

  const event = JSON.parse(req.body.toString());
  if (event.event === "payment.succeeded") {
    // mark order as paid in your DB using event.orderId
  }
  res.send("ok");
});