How to Build an Affiliate Program in Next.js (The Clean Way)

The article shows how to build a self-hosted affiliate program in Next.js by capturing a referral parameter and storing it in a cookie.

It recommends using middleware as the default approach because it runs server-side and avoids client-side JavaScript.

At checkout, the referral value is passed to Stripe so payments can be attributed correctly.

The guide compares DIY tracking with paid tools like Rewardful, FirstPromoter, and Impact.

It also explains referral validation and why cookies are better than localStorage for redirect-based checkout flows.