---
title: "What does the RevenueDot webhook event PRODUCT_CHANGE mean?"
description: "PRODUCT_CHANGE is sent when a customer changes product: an upgrade now, or a downgrade or crossgrade scheduled for the next renewal. product_id is the old product."
url: https://revenuedot.app/docs/webhooks/webhook-product-change
---

# What does the RevenueDot webhook event PRODUCT_CHANGE mean?

The RevenueDot webhook event PRODUCT_CHANGE means a customer switched a subscription to another product, now or at the next renewal.

## Quick facts

| | |
|---|---|
| Event | `PRODUCT_CHANGE` |
| Where | RevenueDot webhook (`event.type`), RevenueCat's webhook format |
| Sent to | Every enabled webhook whose filters match |
| Fields that are specific to it | `new_product_id` |
| What it means | The customer changed product: an upgrade now, or a downgrade or crossgrade scheduled for the next renewal. `product_id` is the old product. |

## When it is sent

- An upgrade takes effect at once. The event names the old product in `product_id` and the new one in `new_product_id`.
- A downgrade or crossgrade is announced when it is scheduled, and takes effect at the next renewal.
- A scheduled switch reaching its renewal is only a `RENEWAL`, because it was announced before.

## What your server should do

1. For an upgrade, switch the entitlement to `new_product_id` now.
2. For a scheduled change, keep the current product and plan the switch for the renewal.
3. Do not treat the old product's end as a cancellation: no `CANCELLATION` or `EXPIRATION` is sent for it.
4. Deduplicate on `event.id`: deliveries can repeat, because anything but HTTP 200 is retried after 5, 10, 20, 40 and 80 minutes.

## Example

```javascript
import { createHmac, timingSafeEqual } from "node:crypto";

// X-RevenueCat-Webhook-Signature: t=<unix seconds>,v1=<hex HMAC-SHA256 of "<t>.<raw body>">
function verify(rawBody, header, secret, toleranceSeconds = 300) {
  const m = /^t=(\d+),v1=([0-9a-f]{64})$/.exec(header ?? "");
  if (!m || Math.abs(Date.now() / 1000 - Number(m[1])) > toleranceSeconds) return false;
  const expected = createHmac("sha256", secret).update(`${m[1]}.${rawBody}`).digest();
  return timingSafeEqual(expected, Buffer.from(m[2], "hex"));
}

// Sign a sample delivery the way RevenueDot does, then handle it.
const secret = "whsec_test_secret";
const rawBody = JSON.stringify({ api_version: "1.0", event: {"id":"66339910-3BFF-49F4-B873-D1283D673DE2","type":"PRODUCT_CHANGE","app_user_id":"user_1","product_id":"pro_monthly","new_product_id":"pro_annual"} });
const t = Math.floor(Date.now() / 1000);
const header = `t=${t},v1=${createHmac("sha256", secret).update(`${t}.${rawBody}`).digest("hex")}`;

const seen = new Set(); // use a database table in production

function handle(rawBody, header) {
  if (!verify(rawBody, header, secret)) return "401 bad signature";
  const { event } = JSON.parse(rawBody);
  if (seen.has(event.id)) return "200 duplicate";
  seen.add(event.id);
  if (event.type !== "PRODUCT_CHANGE") return "200 ignored";
  return "move " + event.app_user_id + " from " + event.product_id + " to " + event.new_product_id;
}

console.log(handle(rawBody, header));
```

*Run-checked: `npm run check:snippets` runs this snippet with Node and compares its output with `from pro_monthly to pro_annual` (checked 2026-10-03).*

## How RevenueDot produces it

`diffSubscription` returns `PRODUCT_CHANGE` when the product on the chain changes without having been announced (`fromProduct` becomes `product_id`), and when a different `autoRenewProductId` appears for the next renewal.

## Related

- [What does the RevenueDot webhook event RENEWAL mean?](https://revenuedot.app/docs/webhooks/webhook-renewal.md)
- [What does the RevenueDot webhook event INITIAL_PURCHASE mean?](https://revenuedot.app/docs/webhooks/webhook-initial-purchase.md)
- [What does the RevenueDot webhook event CANCELLATION mean?](https://revenuedot.app/docs/webhooks/webhook-cancellation.md)
- [PRODUCT_CHANGE fields and a recorded example payload](https://revenuedot.app/docs/api/webhook-events.md#product_change)
- [Webhooks guide: set up, verify and test](https://revenuedot.app/docs/guides/webhooks.md)

## Source

- [RevenueDot docs: which webhook events RevenueDot sends](https://revenuedot.app/docs/api/webhook-events)
- [RevenueCat: webhook event types and fields (the format RevenueDot follows)](https://www.revenuecat.com/docs/integrations/webhooks/event-types-and-fields)
- [RevenueDot core: events.ts (the event types and the rules that derive them)](https://github.com/revenuedot/revenuedot/blob/main/packages/core/src/events.ts)
- [RevenueDot server: services/events.ts (how an event is recorded and delivered)](https://github.com/revenuedot/revenuedot/blob/main/apps/server/src/services/events.ts)
- [RevenueDot server: services/purchases.ts (where store changes become events)](https://github.com/revenuedot/revenuedot/blob/main/apps/server/src/services/purchases.ts)

Checked: 2026-10-03