diff --git a/env.example b/env.example
index 1380cb6..abd45c2 100644
--- a/env.example
+++ b/env.example
@@ -129,3 +129,9 @@ NEXT_PUBLIC_DATAFAST_ANALYTICS_DOMAIN=""
 # -----------------------------------------------------------------------------
 NEXT_PUBLIC_DISCORD_WIDGET_SERVER_ID=""
 NEXT_PUBLIC_DISCORD_WIDGET_CHANNEL_ID=""
+
+# -----------------------------------------------------------------------------
+# Affiliate (Affonso)
+# https://mksaas.com/docs/affiliate
+# -----------------------------------------------------------------------------
+NEXT_PUBLIC_AFFILIATE_AFFONSO_ID=""
diff --git a/src/app/[locale]/(marketing)/(home)/page.tsx b/src/app/[locale]/(marketing)/(home)/page.tsx
index 19e68fd..6433930 100644
--- a/src/app/[locale]/(marketing)/(home)/page.tsx
+++ b/src/app/[locale]/(marketing)/(home)/page.tsx
@@ -12,7 +12,6 @@ import StatsSection from '@/components/blocks/stats/stats';
 import TestimonialsSection from '@/components/blocks/testimonials/testimonials';
 import { NewsletterCard } from '@/components/newsletter/newsletter-card';
 import DiscordWidget from '@/components/shared/discord-widget';
-import { websiteConfig } from '@/config/website';
 import { constructMetadata } from '@/lib/metadata';
 import { getUrlWithLocale } from '@/lib/urls/urls';
 import type { Metadata } from 'next';
diff --git a/src/components/affiliate/affonso.tsx b/src/components/affiliate/affonso.tsx
new file mode 100644
index 0000000..73df2f5
--- /dev/null
+++ b/src/components/affiliate/affonso.tsx
@@ -0,0 +1,33 @@
+'use client';
+
+import { websiteConfig } from '@/config/website';
+import Script from 'next/script';
+
+/**
+ * Affonso Affiliate
+ *
+ * https://affonso.com
+ */
+export function AffonsoAffiliate() {
+  if (process.env.NODE_ENV !== 'production') {
+    return null;
+  }
+
+  if (!websiteConfig.features.enableAffonsoAffiliate) {
+    return null;
+  }
+
+  const affiliateId = process.env.NEXT_PUBLIC_AFFILIATE_AFFONSO_ID as string;
+  if (!affiliateId) {
+    return null;
+  }
+
+  return (
+    <Script
+      src="https://affonso.io/js/pixel.min.js"
+      strategy="afterInteractive"
+      data-affonso={affiliateId}
+      data-cookie_duration="30"
+    />
+  );
+}
diff --git a/src/components/auth/register-form.tsx b/src/components/auth/register-form.tsx
index cd1549b..390f8ba 100644
--- a/src/components/auth/register-form.tsx
+++ b/src/components/auth/register-form.tsx
@@ -13,6 +13,7 @@ import {
   FormMessage,
 } from '@/components/ui/form';
 import { Input } from '@/components/ui/input';
+import { websiteConfig } from '@/config/website';
 import { authClient } from '@/lib/auth-client';
 import { getUrlWithLocaleInCallbackUrl } from '@/lib/urls/urls';
 import { DEFAULT_LOGIN_REDIRECT, Routes } from '@/routes';
@@ -97,6 +98,13 @@ export const RegisterForm = ({
           // sign up success, user information stored in ctx.data
           // console.log("register, success:", ctx.data);
           setSuccess(t('checkEmail'));
+
+          // add affonso affiliate
+          // https://affonso.io/app/affiliate-program/connect
+          if (websiteConfig.features.enableAffonsoAffiliate) {
+            console.log('register, affonso affiliate:', values.email);
+            window.Affonso.signup(values.email);
+          }
         },
         onError: (ctx) => {
           // sign up fail, display the error message
diff --git a/src/components/dashboard/dashboard-sidebar.tsx b/src/components/dashboard/dashboard-sidebar.tsx
index 247b8f2..f010307 100644
--- a/src/components/dashboard/dashboard-sidebar.tsx
+++ b/src/components/dashboard/dashboard-sidebar.tsx
@@ -13,7 +13,6 @@ import {
   useSidebar,
 } from '@/components/ui/sidebar';
 import { getSidebarLinks } from '@/config/sidebar-config';
-import { websiteConfig } from '@/config/website';
 import { LocaleLink } from '@/i18n/navigation';
 import { authClient } from '@/lib/auth-client';
 import { Routes } from '@/routes';
diff --git a/src/components/pricing/create-checkout-button.tsx b/src/components/pricing/create-checkout-button.tsx
index e78ef26..3a1d0e9 100644
--- a/src/components/pricing/create-checkout-button.tsx
+++ b/src/components/pricing/create-checkout-button.tsx
@@ -2,6 +2,7 @@
 
 import { createCheckoutAction } from '@/actions/create-checkout-session';
 import { Button } from '@/components/ui/button';
+import { websiteConfig } from '@/config/website';
 import { Loader2Icon } from 'lucide-react';
 import { useTranslations } from 'next-intl';
 import { useState } from 'react';
@@ -50,12 +51,35 @@ export function CheckoutButton({
     try {
       setIsLoading(true);
 
+      const mergedMetadata = metadata ? { ...metadata } : {};
+
+      // add affonso_referral to metadata if enabled affonso affiliate
+      if (websiteConfig.features.enableAffonsoAffiliate) {
+        const affonsoReferral =
+          typeof document !== 'undefined'
+            ? (() => {
+                const match = document.cookie.match(
+                  /(?:^|; )affonso_referral=([^;]*)/
+                );
+                return match ? decodeURIComponent(match[1]) : null;
+              })()
+            : null;
+        if (affonsoReferral) {
+          console.log(
+            'create checkout button, affonsoReferral:',
+            affonsoReferral
+          );
+          mergedMetadata.affonso_referral = affonsoReferral;
+        }
+      }
+
       // Create checkout session using server action
       const result = await createCheckoutAction({
         userId,
         planId,
         priceId,
-        metadata,
+        metadata:
+          Object.keys(mergedMetadata).length > 0 ? mergedMetadata : undefined,
       });
 
       // Redirect to checkout page
diff --git a/src/config/website.tsx b/src/config/website.tsx
index 0f7cf25..925f7e2 100644
--- a/src/config/website.tsx
+++ b/src/config/website.tsx
@@ -35,6 +35,7 @@ export const websiteConfig: WebsiteConfig = {
   features: {
     enableDiscordWidget: true,
     enableUpgradeCard: true,
+    enableAffonsoAffiliate: false,
   },
   routes: {
     defaultLoginRedirect: '/dashboard',
diff --git a/src/types/index.d.ts b/src/types/index.d.ts
index c195cd3..b9a864a 100644
--- a/src/types/index.d.ts
+++ b/src/types/index.d.ts
@@ -67,6 +67,7 @@ export interface SocialConfig {
 export interface FeaturesConfig {
   enableDiscordWidget?: boolean;      // Whether to enable the discord widget
   enableUpgradeCard?: boolean;        // Whether to enable the upgrade card in the sidebar
+  enableAffonsoAffiliate?: boolean;   // Whether to enable affonso affiliate
 }
 
 /**