Show shoppers their best card at checkout.

SuperPay in one paragraph

SuperPay is the AI-powered payment intelligence layer for the modern wallet. On the consumer side we tell shoppers which card to use at every merchant, surface unused perks, and forecast their best path to maximum rewards. On the merchant side, our Checkout API adds a smart card-recommendation widget to your checkout — showing shoppers exactly which card maximizes their rewards on this purchase. No integration with your payment processor required.

What you get as a partner

• A REST API to query card recommendations for any checkout session.
• A drop-in widget (one <script> tag) that renders the card recommendation on your existing checkout.
• Sandbox + production environments with revocable, scoped API keys and origin allowlisting.
• Distribution to the SuperPay shopper base — featured placement, push, and in-app discovery.
• A real human on launch: hello@superpayrewards.com.

Reward visibility drives purchase confidence.

Shoppers with multiple credit cards face decision fatigue at checkout. Which card should I use? Am I missing rewards? That hesitation costs you conversions. SuperPay removes the question entirely.

You're a great fit if…

• You sell direct to consumer online and protect a brand price.
• You run premium, considered-purchase products (apparel, beauty, electronics, travel, subscriptions) where a 10–20% discount damages positioning.
• You have an email or SMS list you want to reactivate without resorting to a code drop.
• You want category-level distribution — appearing in front of shoppers who are already optimizing their card spend.

Probably not a fit (yet)

• Pure marketplaces where you don't control checkout.
• Hyper-low-margin commodity goods where every dollar of reward eats the unit.
• Regulated categories where promotional rewards trigger compliance review (we'll talk first).

Three calls. That's the integration.

1. Mint a reward from your server with the amount, expiry, and any targeting.
2. Attach it to a checkout session by passing the reward token to the SuperPay widget on your checkout page.
3. Verify redemption server-side via webhook or polling once the shopper completes purchase.

Lifecycle of a single reward

Get to a working sandbox in under 15 minutes

Step 1 — Get your sandbox key

Visit /for-merchants, fill in your business name, contact email, and store origins (the domains where the widget will be embedded). You'll receive a verification email — click it and your sandbox key is provisioned immediately.

Step 2 — Mint your first reward

From your server, call POST /v1/rewards with the SuperPay sandbox secret key. Use idempotency keys to make this safe to retry.

curl -X POST https://superpayrewards.com/v1/rewards \
  -H "Authorization: Bearer sk_sandbox_..." \
  -H "Idempotency-Key: order_98123" \
  -H "Content-Type: application/json" \
  -d '{
    "amountCents": 750,
    "currency": "USD",
    "expiresInSeconds": 1800,
    "metadata": { "orderRef": "order_98123" }
  }'

Response:

{
  "rewardToken": "rwd_live_8e3...d2",
  "amountCents": 750,
  "expiresAt": "2026-05-03T22:14:00Z"
}

Step 3 — Embed the widget on your checkout

Drop the script tag near the bottom of your cart or checkout page and pass the reward token via data-reward.

<script
  src="https://superpayrewards.com/v1/widget.js"
  data-key="pk_sandbox_..."
  data-reward="rwd_live_8e3...d2"
  async></script>

Step 4 — Confirm redemption after purchase

When your order webhook fires, confirm the reward server-to-server. SuperPay only credits the shopper after this call.

POST /v1/rewards/rwd_live_8e3...d2/confirm
Authorization: Bearer sk_sandbox_...

{
  "orderId": "order_98123",
  "amountChargedCents": 12900
}

Step 5 — Promote to production

Email hello@superpayrewards.com with your sandbox merchant ID and the production domain(s). We'll issue a pk_live_ + sk_live_ pair and walk through your first 100 live transactions together.

One script tag. Your branding. Our reward affordance.

The SuperPay widget renders as a non-intrusive badge or button on your checkout. It's framework-agnostic — works inside Shopify themes, custom React/Vue checkouts, BigCommerce, WooCommerce, and bare HTML.

Customization options

Reference snippets

Node.js (Express)

import express from "express";
const app = express();

app.post("/cart/checkout", async (req, res) => {
  const reward = await fetch("https://superpayrewards.com/v1/rewards", {
    method: "POST",
    headers: {
      Authorization: `Bearer ${process.env.SUPERPAY_SECRET}`,
      "Content-Type": "application/json",
      "Idempotency-Key": req.body.cartId,
    },
    body: JSON.stringify({
      amountCents: Math.round(req.body.subtotal * 0.05),
      currency: "USD",
      expiresInSeconds: 1800,
      metadata: { cartId: req.body.cartId },
    }),
  }).then(r => r.json());

  res.render("checkout", { rewardToken: reward.rewardToken });
});

Python (Django/Flask)

import os, requests

def create_reward(cart_id, subtotal_cents):
    r = requests.post(
        "https://superpayrewards.com/v1/rewards",
        headers={
            "Authorization": f"Bearer {os.environ['SUPERPAY_SECRET']}",
            "Idempotency-Key": cart_id,
        },
        json={
            "amountCents": subtotal_cents // 20,  # 5% reward
            "currency": "USD",
            "expiresInSeconds": 1800,
            "metadata": {"cartId": cart_id},
        },
        timeout=5,
    )
    r.raise_for_status()
    return r.json()["rewardToken"]

Shopify (Liquid theme)

<!-- in your cart.liquid or checkout.liquid -->
<div id="superpay"></div>
<script
  src="https://superpayrewards.com/v1/widget.js"
  data-key="{{ settings.superpay_publishable_key }}"
  data-reward="{{ checkout.attributes.superpay_token }}"
  data-variant="inline"
  async></script>

Free, forever.

The Card-Recommendation Widget is 100% free for merchants. No fees, no rev share, no contract minimums. SuperPay treats the widget as a value-add at checkout and a shopper-acquisition channel.

Questions about the API or want to discuss a custom integration? Email hello@superpayrewards.com.

What we do, what we don't

Need our security policy or to start a vendor review? View our security policy or email security@superpayrewards.com.

Common questions

Ready to ship?

Pre-launch checklist

• ☐ Sandbox key issued and successfully minting rewards
• ☐ Widget rendering on your staging checkout
• ☐ Server-side confirm endpoint wired to your order webhook
• ☐ Production domain(s) added to allowlist
• ☐ Reward amount + expiry policy decided
• ☐ Customer support team briefed on the affordance
• ☐ pk_live_ / sk_live_ keys issued and rotated into your env

Useful links

• /for-merchants — sign up & live widget demo
• /v1/docs — full API reference
• Download this guide as a PDF
• /blog — product & rewards strategy writing
• /security — security policy