route.ts
For the full content of this gist, refer to https://gist.github.com/CodingAbdullah/74120c80b2e3f1578284dd07fe43fac8
McMaster. Software Engineer with a keen interest in blockchain and web3.
import { auth } from "@clerk/nextjs/server";
import { Polar } from "@polar-sh/sdk";
import { NextRequest, NextResponse } from "next/server";
import { db } from "@/db/index";
import { users } from "@/db/schema";
import { eq } from "drizzle-orm";
import PLAN_TO_PRODUCT from "@/app/_utils/planToProductRecord";
// Setting up the Polar instance for processing payments
const polar = new Polar({
accessToken: process.env.POLAR_ACCESS_TOKEN!,
server: "sandbox"
});
// API route to change the user's subscription plan
export async function POST(req: NextRequest) {
const { userId } = await auth();
if (!userId) {
throw new Error("Unauthorized");
}
const { plan } = await req.json();
if (!plan || !PLAN_TO_PRODUCT[plan]) {
throw new Error("Invalid plan");
}
const user = await db.query.users.findFirst({
where: eq(users.clerkId, userId)
});
if (!user || !user.polarSubscriptionId) {
throw new Error("No active subscription found");
}
// Update method for changing the subscription plan
try {
await polar.subscriptions.update({
id: user.polarSubscriptionId,
subscriptionUpdate: { productId: PLAN_TO_PRODUCT[plan]! }
});
return NextResponse.json({ success: true });
} catch (error) {
console.error("[Subscription Change] Error:", error);
// If subscription is already cancelled, clear it and tell frontend to use checkout
if (String(error).includes("AlreadyCanceledSubscription")) {
await db
.update(users)
.set({
polarSubscriptionId: null,
isSubscribed: false,
subscriptionTier: "free",
updatedAt: new Date()
})
.where(eq(users.clerkId, userId));
return NextResponse.json({ error: "cancelled", useCheckout: true }, { status: 400 });
}
return NextResponse.json({ error: String(error) }, { status: 500 });
}
}