Test, release and update the EPP

Test the EPP using payments in sandbox, enable debug mode and learn about how to keep the EPP up to date.

Set debug mode

To help identify issues, the embedded payment page offers a debug mode that logs every operation to the Console. Simply set debugMode: true.

import { Payment } from 'truelayer-embedded-payment-page'
const payment = Payment({
  payment_id: 'example-string',
  resource_token: 'example-string',
  return_uri: 'example-string',
  debugMode: true,


By default, the embedded payment page runs in sandbox. This allows you to test the EPP with payments in sandbox (though you won't be able to process live payments).

When you’re ready to go live, start using the Payments API live environment. Switch the embedded payment page to production on initialisation production: true.

import { Payment } from 'truelayer-embedded-payment-page'
const payment = Payment({
  production: true

Keep the EPP updated

The embedded payment page broadly consists of two components. Handle updates for each component differently.

The on-screen elements and the payment flow are all hosted by TrueLayer. Any changes that we make here will be visible to your users straight away, without you having to make any updates.

The embedded payment page JavaScript package, which sets up the view, is downloaded from NPM and installed on your web page. From time to time we may change how this component works: for example, there may be new parameters that you can pass on initialisation to configure the user flow. Once you've installed the latest embedded payment page version from NPM, you can take advantage of these changes.