Add an affiliate program to your app

1. Create your LinkJolt account

Sign up at https://www.linkjolt.io/auth/sign-up. Plans start at $19.99 a month, with a 7-day free trial (card required) and 0% of your sales taken.

Create a campaign: the commission (for example 20% of every payment, renewals included) and the page affiliate links send people to.

Working in Claude Code or Codex? Add the LinkJolt connector (below) and your agent can read your setup and tracking script and name the business before you pick a plan, then create the campaign once your trial has started. You sign in once in the browser.

2. Connect where you take payment

In LinkJolt, open Integrations and pick your provider. This is the step that sends sales to LinkJolt, and it happens in your browser: an agent cannot approve it for you.

• Stripe: Integrations → Stripe → Set up with Stripe, then approve once on Stripe. No webhook to create, no secret to paste.
• Paddle: Integrations → Paddle → paste a Paddle API key that can write notification settings. LinkJolt creates the notification destination.
• Polar: Integrations → Polar → approve once. LinkJolt creates the webhook.
• Creem: Integrations → Creem → paste a Creem API key. LinkJolt creates the webhook.
• Lemon Squeezy and Gumroad: add the webhook LinkJolt shows on that Integrations tab.
• Everything else: follow that platform's Integrations tab; the platform files in step 4 have the same steps.

3. Add the tracking script

Put the script on every page of the site, in the root layout. Your merchant id is in the script tag shown on Integrations (or ask the connector for it).

When a visitor arrives through an affiliate link (?tc=...&aff=...), the script keeps the referral for 30 days and exposes it as window.linkjolt.referral, a string like tc_abc_aff_xyz_cid_123. On a visit without an affiliate it is empty.

import Script from 'next/script';

// inside <body> of the root layout
<Script src="https://www.linkjolt.io/api/tracking.js?id=YOUR_MERCHANT_ID" strategy="afterInteractive" />

TypeScript projects can declare the global once:

// global.d.ts, so window.linkjolt type-checks
interface Window {
  linkjolt?: { referral: string | null };
}

4. Pass the referral to checkout

Find how the app takes payment and make the one change for it. Never rename the field or put the referral anywhere else: that field is what LinkJolt reads. Renewals, refunds and plan changes are tracked from the first payment, so there is nothing to build for them.

// Browser: the page that starts checkout
const referral = window.linkjolt?.referral || '';
const res = await fetch('/api/checkout', {
  method: 'POST',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({ priceId, referral }),
});

// Server: where the Checkout Session is created
const { priceId, referral } = await req.json();
const session = await stripe.checkout.sessions.create({
  // ...your existing options
  client_reference_id: referral || undefined,
});

paddle.Checkout.open({
  items: [{ priceId, quantity: 1 }],
  customData: { linkjolt: window.linkjolt?.referral || '' },
});

const checkout = await polar.checkouts.create({
  products: [productId],
  successUrl,
  metadata: referral ? { reference_id: referral } : {},
});

import { Creem } from "creem";
const creem = new Creem({ apiKey: process.env.CREEM_API_KEY });

const checkout = await creem.checkouts.create({
  productId: "prod_123",
  successUrl: "https://example.com/thanks",
  metadata: { linkjolt_ref: referral },   // the value from window.linkjolt.referral
});
// send the customer to checkout.checkoutUrl

Other platforms

• WooCommerce: /developers/quickstart/woocommerce.md
• Squarespace: /developers/quickstart/squarespace.md
• BigCommerce: /developers/quickstart/bigcommerce.md
• Teachable: /developers/quickstart/teachable.md
• Carrd: /developers/quickstart/carrd.md
• Webflow: /developers/quickstart/webflow.md
• GoPay: /developers/quickstart/gopay.md
• Fourthwall: /developers/quickstart/fourthwall.md
• Apple In-App Purchases: /developers/quickstart/apple-iap.md
• Shopify app billing: /developers/quickstart/shopify-app-billing.md

5. Check it with a test sale

Open the site with ?tc=TEST&aff=TEST and run window.linkjolt.referral in the browser console: it should print tc_TEST_aff_TEST.

For a real check, use the test link on the Integrations page and buy in your provider's test mode. With Set up with Stripe, a Stripe test-mode purchase is recorded as a test sale (a Stripe sandbox is a separate account, so it is not). Creem test-mode purchases and Paddle sandbox purchases with a sandbox key connected are test sales too. Test sales are listed under Commissions → Test sales, apart from real commissions.