Set referral discount via Dub Customer object

apps/web/app/api/workspaces/[idOrSlug]/billing/upgrade/route.ts

@@ -1,4 +1,5 @@
 import { withWorkspace } from "@/lib/auth";
+import { getDubCustomer } from "@/lib/dub";
 import { stripe } from "@/lib/stripe";
 import { APP_DOMAIN } from "@dub/utils";
 import { NextResponse } from "next/server";
@@ -46,6 +47,10 @@ export const POST = withWorkspace(async ({ req, workspace, session }) => {
     });
     return NextResponse.json({ url });
   } else {
+    const customer = await getDubCustomer(session.user.id);
+    const isReferral =
+      customer?.link?.programId === "prog_d8pl69xXCv4AoHNT281pHQdo";
+
     // For both new users and users with canceled subscriptions
     const stripeSession = await stripe.checkout.sessions.create({
       ...(workspace.stripeId
@@ -64,7 +69,18 @@ export const POST = withWorkspace(async ({ req, workspace, session }) => {
       success_url: `${APP_DOMAIN}/${workspace.slug}?${onboarding ? "onboarded" : "upgraded"}=true&plan=${plan}&period=${period}`,
       cancel_url: baseUrl,
       line_items: [{ price: prices.data[0].id, quantity: 1 }],
-      allow_promotion_codes: true,
+      ...(isReferral
+        ? {
+            discounts: [
+              {
+                coupon:
+                  process.env.NODE_ENV === "production"
+                    ? "pEVpzGQE"
+                    : "k8v8KtqG",
+              },
+            ],
+          }
+        : { allow_promotion_codes: true }),
       automatic_tax: {
         enabled: true,
       },

apps/web/lib/dub.ts

@@ -1,3 +1,14 @@
 import { Dub } from "dub";
 
 export const dub = new Dub();
+
+// fetch Dub customer using their external ID (ID in our database)
+export const getDubCustomer = async (userId: string) => {
+  try {
+    return await dub.customers.get({
+      id: `ext_${userId}`,
+    });
+  } catch (error) {
+    return null;
+  }
+};

apps/web/package.json

@@ -64,7 +64,7 @@
     "concurrently": "^8.0.1",
     "csv-parse": "^5.5.6",
     "date-fns": "^3.6.0",
-    "dub": "^0.46.1",
+    "dub": "^0.46.8",
     "framer-motion": "^10.16.16",
     "fuse.js": "^6.6.2",
     "geist": "^1.3.1",