# Other Paddle methods

> Attribute Paddle payments by the customer's email when the checkout can't carry the visitor ID.

Source: https://metricraven.com/docs/paddle-other-methods  
Markdown: https://metricraven.com/docs/paddle-other-methods.md  
Section: Revenue

If you open checkouts with Paddle.js or create transactions on your server, pass the visitor ID as in [Connect Paddle](https://metricraven.com/docs/paddle). For every other flow, the buyer's email links the payment to the visit.

## Send the buyer's email from the browser

When you can't put the visitor ID in the checkout's custom data (a third-party storefront, a no-code tool, a mobile app or an older checkout), tell MetricRaven which email this visitor is paying with. A Paddle payment with that customer email, made within an hour, is credited to the visit.

1. **Connect Paddle**

   Follow [Connect Paddle](https://metricraven.com/docs/paddle) first: payments arrive through its webhook.

2. **Call payment() after a successful payment**

   On the page buyers land on after paying, pass the email they paid with:

   ```javascript
   // On the page buyers see after paying, with the email they paid with.
   window.metricraven.payment({ email: "customer@example.com" });
   ```

3. **Make the call safe before the script loads (recommended)**

   Add this to the page's `<head>`, above other scripts. Calls made before the MetricRaven script loads are queued and sent as soon as it does.

   ```html title="Queue stub"
   <script>
     // Keeps the call until the MetricRaven script has loaded, then replays it.
     window.metricraven = window.metricraven || { q: [] };
     window.metricraven.payment = window.metricraven.payment || function () {
       window.metricraven.q.push(["payment"].concat([].slice.call(arguments)));
     };
   </script>
   ```

## Example: a React welcome page

If checkout redirects to `/welcome`, call it when the page loads:

```jsx title="app/welcome/page.jsx"
"use client";
import { useEffect } from "react";

// The page your checkout redirects to, e.g. /welcome, with the signed-in buyer.
export default function Welcome({ user }) {
  useEffect(() => {
    if (!user?.email) return;
    if (window.metricraven?.payment) {
      window.metricraven.payment({ email: user.email });
    } else {
      window.metricraven = window.metricraven || { q: [] };
      window.metricraven.q.push(["payment", { email: user.email }]);
    }
  }, [user?.email]);
  return <h1>Welcome aboard</h1>;
}
```

With the [npm package](https://metricraven.com/docs/npm-package), the call is `payment({ email })` from `@metricraven/web`.

## When to use this

- Checkouts where you can't set custom data, including third-party tools that sell through Paddle.
- Flows where the buyer's email is known on the page after payment.

When you can pass the visitor ID at checkout, prefer that: it's exact and needs no email.

## Notes

- Repeat calls are ignored, so reloading the page can't double anything. Payments themselves still come only from the webhook.
- It only fills in payments that have no other link to a visit, and never replaces a visitor ID, user ID or server-side identify.
- Paddle transactions carry only a customer ID. In your notification destination, also select `customer.created` and `customer.updated` so the customer's email can be matched. Only a keyed hash of it is kept.
- Matching rules, privacy and the security model: [Attribute by email](https://metricraven.com/docs/attribute-by-email).