React to inbound webhooks

POST https://<host>/public/{flowId}/webhooks/{endpointId}/{token}

// apps/<app>/src/api/onChargeSucceeded.ts
import { z } from 'zod';
import { createEndpoint } from 'zitejs/backend';
import { zite } from 'zitejs/db';
import { ZiteNotifications } from 'zitejs/notifications';

export default createEndpoint({
  description: 'Notify the team when Stripe reports a successful charge',
  webhook: {},
  inputSchema: z.object({
    id: z.string(),
    type: z.literal('charge.succeeded'), // ← reject every other Stripe event type
    data: z.object({ object: z.object({ amount: z.number(), currency: z.string() }) }),
  }),
  outputSchema: z.object({ ok: z.boolean() }),
  execute: async ({ input }) => {
    // Idempotency is your responsibility — providers retry, so the same delivery
    // can arrive more than once. Dedup on the stable per-delivery id.
    const seen = await zite.WebhookEvents.findOne({ filters: { eventId: input.id } });
    if (seen) return { ok: true };
    await zite.WebhookEvents.create({ record: { eventId: input.id } });

    const { amount, currency } = input.data.object;
    await ZiteNotifications.create({
      recipients: ['user_finance'],
      title: `Payment received: ${(amount / 100).toFixed(2)} ${currency.toUpperCase()}`,
      idempotencyKey: input.id,
    });
    return { ok: true };
  },
});