Use caseFewer subscriptions lost to a declined card, with a WhatsApp message.

Step by step, for real.

1. 1

   The failed payment template

   Claude Code creates it with create_template, in the utility category: an alert on the account. The first name, and an “Update my card” button to your billing page; get_template_status confirms the approval.

2. 2

   The Stripe webhook you already have

   On the invoice.payment_failed event, once Stripe’s signature is checked, your app finds the user behind the Stripe customer.

3. 3

   The send

   It sends the template with POST /v1/sends, with an idempotency key taken from the invoice: the same event delivered twice within 24 hours sends one message.

4. 4

   The card updated

   The user taps the button and updates their card on your billing page, before losing access.

What you type in Claude Code

With the plugin installed, one sentence is enough. The film’s also wires the welcome at sign-up: Claude Code creates both templates, writes the code and tests.

/messagingme:demarrer at sign-up (app/signup.ts), a whatsapp welcome with the link to create their first schedule. and when stripe reports a failed payment, a whatsapp with the link to update their card

The Stripe webhook, as Claude Code writes it

import { messagingme } from '../../../lib/messagingme';
import { userOfCustomer, verifiedStripeEvent } from '../../../lib/billing';

// Your Stripe webhook, the one you already have. The template payment_failed is UTILITY (an account alert): one
// variable, the first name, and a URL button to your billing page.
export async function POST(req: Request) {
  const event = await verifiedStripeEvent(req);
  if (!event) return new Response(null, { status: 400 });
  if (event.type === 'invoice.payment_failed') {
    const invoice = event.data.object;
    const user = await userOfCustomer(invoice.customer);
    if (user) {
      // A failed WhatsApp send never fails the Stripe webhook: Stripe would retry it, then disable it.
      try {
        const send = await messagingme.POST('/v1/sends', {
          body: {
            target: { template: { name: 'payment_failed', language: 'en' } },
            recipients: [{ phone: user.phone, variables: { firstName: user.firstName } }],
            params: [{ position: 1, source: { type: 'variable', key: 'firstName' } }],
          },
          // Stripe may deliver the same event again: within 24 hours, one message per invoice.
          idempotencyKey: `payment-${invoice.id}`,
        });
        // A refused recipient (STOP, plan limit) is not an error: it is listed in skipped, with its reason.
        if (send.skippedTotal > 0) console.warn(`payment ${invoice.id} not sent: ${send.skipped[0]?.reason}`);
      } catch (e) {
        console.error(`payment ${invoice.id}: WhatsApp send failed`, e);
      }
    }
  }
  return new Response(null, { status: 200 });
}

app/api/stripe/route.ts · all the code in the guide