Mint Paddle Customer Portal session URLs from Next.js

When to use this skill

Use this skill when you want Paddle to host the UI for customer self-service — viewing invoices, updating payment methods, canceling subscriptions — and you just want to send the user to that hosted UI from a "Manage subscription" button in your app. It covers a Next.js 15 (App Router) Server Action that authenticates the user, looks up their Paddle customer ID, calls paddle.customerPortalSessions.create, and returns the URL to redirect them to.

This is the portal approach. The alternative is to build a custom billing screen using the Paddle API directly — see "Should you use the portal at all?" below for the trade-off.

Should you use the portal at all?

The Paddle customer portal is one option for letting users manage their subscriptions. The other is to build your own billing UI that talks to the Paddle Node SDK directly. Each has its place:

You can also mix: use the portal for the long tail of management actions (download invoice, change payment method) and build custom UI for the high-value flows (upgrade, with a confirmation showing the prorated charge). The portal session URL has deep links for specific subscription actions if you want to embed them rather than send the user to the overview.

The choice isn't permanent. A common evolution: ship the portal first to unblock customer self-service, then progressively replace specific flows with custom UI as those flows become important to your product.

Prerequisites

• A Paddle account with at least one customer record (sandbox is fine).
• Server-side PADDLE_API_KEY available — this action runs in a Server Action, never in the browser. The key needs the customer_portal_session.write permission.
• A customers table mirrored from webhooks (see subscription-sync). You need the user's Paddle customer_id to mint a session, and you look it up via the email bridge.
• Optionally, a subscriptions table — if you want per-subscription deep links, you pass subscription IDs the customer owns to the SDK.
• An auth system. Examples use Supabase, but any session-based auth works.

NEXT_PUBLIC_PADDLE_ENV=sandbox             # or "production"
PADDLE_API_KEY=pdl_sdbx_apikey_...

NEXT_PUBLIC_SUPABASE_URL=...
NEXT_PUBLIC_SUPABASE_ANON_KEY=...
SUPABASE_SERVICE_ROLE_KEY=...              # or SUPABASE_SECRET_KEY (new opaque sb_secret_*)

Supabase helpers

The action uses two server-side Supabase clients. These match the Paddle Next.js starter kit; if your project already has equivalent helpers, use those instead.

// src/utils/supabase/server.ts — the signed-in user's session (anon key + cookies)
import { createServerClient } from "@supabase/ssr";
import { cookies } from "next/headers";

export async function createClient() {
  const cookieStore = await cookies();

  return createServerClient(
    process.env.NEXT_PUBLIC_SUPABASE_URL!,
    process.env.NEXT_PUBLIC_SUPABASE_ANON_KEY!,
    {
      cookies: {
        getAll() {
          return cookieStore.getAll();
        },
        setAll(cookiesToSet) {
          try {
            cookiesToSet.forEach(({ name, value, options }) =>
              cookieStore.set(name, value, options),
            );
          } catch {
            // Called from a Server Component. Safe to ignore if middleware refreshes sessions.
          }
        },
      },
    },
  );
}

// src/utils/supabase/server-internal.ts — service role, no user session. Server-only.
import { createServerClient } from "@supabase/ssr";

export async function createClient() {
  // No cookies: with the signed-in user's session attached, requests would run
  // as that user and row-level security (RLS) would still apply.
  return createServerClient(
    process.env.NEXT_PUBLIC_SUPABASE_URL!,
    process.env.SUPABASE_SERVICE_ROLE_KEY!,
    { cookies: { getAll: () => [], setAll: () => {} } },
  );
}

The service-role client bypasses RLS, so only use it on the server, after you've checked who the user is. It deliberately skips cookies, so it never picks up a signed-in user's session. If you write your own helpers, don't name the wrapper createServerClient — that's the @supabase/ssr function it calls.

How portal sessions work

const session = await paddle.customerPortalSessions.create(
  customerId, // "ctm_01h..."
  subscriptionIds, // string[] — e.g. ["sub_01h...", "sub_02h..."], or [] for overview only
);

The returned session exposes:

• session.urls.general.overview — the main "open my portal" URL. This is what you redirect the user to for the standard self-service flow. They land on the portal home and can navigate from there.
• session.urls.subscriptions[] — array of per-subscription deep links, one entry per subscriptionId you passed:
  • id — matches the input subscription ID.
  • cancelSubscription — direct link to the cancel UI for that specific sub.
  • updateSubscriptionPaymentMethod — direct link to the payment method UI for that sub.
  • view_subscription (API field) — link to that subscription's page in the portal with no form pre-opened. The Node SDK (3.10.0) doesn't expose it yet, so call POST /customers/{customer_id}/portal-sessions directly if you need it.

subscriptionIds can hold up to 25 unique IDs, and each must belong to the customer — otherwise the API returns a 400. For an overview-only link, pass an empty array: the portal still works for general account and invoice access; you just don't get per-subscription deep links.

These URLs are temporary and expire. Treat them as sensitive: anyone with a link can open the customer's portal until it expires. Don't cache or store them — mint a fresh session every time the user clicks Manage.

The full Server Action

// src/actions/portal.ts
"use server";

import { ApiError } from "@paddle/paddle-node-sdk";
import { getPaddleInstance } from "@/utils/paddle/get-paddle-instance";
import { createClient } from "@/utils/supabase/server";
import { createClient as createAdminClient } from "@/utils/supabase/server-internal";

export async function createPortalSession() {
  // 1. Authenticate. Reject anonymous requests before any DB query or SDK call.
  const supabase = await createClient();
  const {
    data: { user },
  } = await supabase.auth.getUser();
  if (!user || !user.email) {
    return { error: "Not authenticated" };
  }

  // 2. Look up the authenticated user's Paddle customer_id via the email
  //    bridge. The customers table is the mirror your webhook handler
  //    populates from customer.created / customer.updated events.
  const admin = await createAdminClient();
  const { data: customerRow } = await admin
    .from("customers")
    .select("customer_id")
    .eq("email", user.email)
    .single();

  if (!customerRow?.customer_id) {
    // The user signed up but hasn't completed a checkout yet, so no Paddle
    // customer record exists. Don't pass an empty string to the SDK — it
    // will 400. Either redirect them to a "subscribe first" page or return
    // a clear error the UI can render.
    return { error: "No Paddle customer" };
  }

  // 3. Mint the session. Notice the customerId comes from step 2 (the
  //    authenticated user's record), NOT from any input parameter — a user
  //    must never be able to request a portal session for someone else's ID.
  //    This action only needs the overview URL, so it passes no subscription
  //    IDs. For deep links, pass up to 25 IDs this customer owns.
  try {
    const paddle = getPaddleInstance();
    const session = await paddle.customerPortalSessions.create(customerRow.customer_id, []);

    // 4. Return ONLY the URL. Don't leak the raw session object — it includes
    //    the customer_id, session id, and full deep-link table that the client
    //    doesn't need for a "redirect to portal" flow.
    return { url: session.urls.general.overview };
  } catch (error) {
    // 5. Turn Paddle API errors into a message the UI can show; rethrow anything else.
    if (error instanceof ApiError) {
      console.error("Portal session failed", error.code, error.detail);
      return { error: "Couldn't open the billing portal. Please try again." };
    }
    throw error;
  }
}

The client component calling this is trivial:

// src/components/manage-subscription-button.tsx
"use client";
import { createPortalSession } from "@/actions/portal";

export function ManageSubscriptionButton() {
  return (
    <button
      onClick={async () => {
        const result = await createPortalSession();
        if ("error" in result) {
          // surface the error to the user
          return;
        }
        window.location.href = result.url;
      }}
    >
      Manage subscription
    </button>
  );
}

Security model

Three things matter:

1. Auth before anything else. The action must check the session before any DB query or SDK call. A portal URL is a key to a customer's billing data — minting one for an unauthenticated request is a critical bug.
2. customerId from the authenticated user, not from input. The action takes no customerId parameter (or any client-supplied identifier that influences which customer's portal is created). The customerId is resolved server-side from the auth session via the customers table. This prevents an authenticated user from requesting "the portal URL for ctm_01h-someone-else."
3. Return only the URL. The full session object includes customerId, the session ID, and the deep-link table. The client only needs the redirect URL — return only that.

Common pitfalls

• No auth check. Server Actions are callable from anywhere — anonymous, scripted, direct POST. Without auth, anyone can mint portal URLs.
• Trusting customerId from the action input. Any pattern where the client passes a customerId and the action uses it directly is a security hole — an authed user could request a portal for any customer they know the ID of.
• Caching the URL. Portal links expire, so a cached link eventually fails — and until then, a stored link opens the customer's billing for anyone who has it. Always mint a fresh session per click.
• Returning the raw session object. Leaks customer_id, session metadata, and per-subscription deep links the client doesn't need. Return only urls.general.overview (or, if you do need the deep links for embedding, the specific URL — never the whole session).
• Not handling the no-customer case. A new user who hasn't checked out yet has no Paddle customer_id. Passing an empty string or null to customerPortalSessions.create returns a 400 with a confusing error. Detect the missing customer explicitly and surface a "subscribe first" message.
• Passing subscription IDs you haven't checked. More than 25 IDs, duplicates, or an ID that belongs to another customer makes the whole request fail with a 400. Pass only IDs from the authenticated customer's rows, or none for an overview link.
• Confusing "open the portal" with "cancel via the portal". urls.general.overview is the home of the portal — it lets the user do anything the portal supports. If you want to send the user directly to the cancel UI (for a specific subscription), use urls.subscriptions[i].cancelSubscription instead; for that subscription's page with no form open, use view_subscription. Most apps just use the overview.
• Using the portal when you should use a custom screen, or vice versa. The portal-vs-custom decision is a real product decision (see "Should you use the portal at all?" above), not just a coding shortcut. If you want a retention step at cancel, the portal can show your Paddle Retain cancellation flows once you've set them up (automatically-collected subscriptions only); for retention logic beyond that, build it custom. If you don't have brand-or-flow requirements, the portal is the right call until you do.

Verify the integration

1. As a logged-in user with a Paddle customer record (i.e. one who has completed a sandbox checkout), click "Manage subscription." The action should return { url: '<some https url>' }. Visiting that URL opens the portal home.
2. Confirm the URL is unique on every click — the urls.general.overview value should differ each time. If it doesn't, you're caching the session.
3. Try the action while logged out. Confirm it returns { error: 'Not authenticated' } and the SDK was NOT called.
4. Try the action as a brand-new user (no checkout completed, no row in customers). Confirm it returns { error: 'No Paddle customer' } and the SDK was NOT called.
5. (If you've added input parameters to the action — don't, but if you have for some other reason —) confirm there is no way for the action to mint a portal URL for a customer the authenticated user doesn't own.
6. If you pass subscription IDs for deep links, inspect the response from customerPortalSessions.create directly. Confirm session.urls.subscriptions includes an entry for each ID you passed, with cancelSubscription and updateSubscriptionPaymentMethod URLs you could use as deep links elsewhere.

Related docs

• Customer portal overview
• customerPortalSessions.create API reference
• Paddle Node SDK reference
• Reference implementation (the custom screen approach, not portal): paddle-nextjs-starter-kit — see src/app/dashboard/subscriptions/ and src/app/dashboard/payments/.