> For the complete documentation index, see [llms.txt](https://amplify-docs.gitbook.io/amplify/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://amplify-docs.gitbook.io/amplify/english/sdk/events.md).

# Events

Knowing when things happen and reacting in a customized way is part of the essence of Amplify SDK. For this, we expose the following events:

| Event name    | Description                                                                               | Params          |
| ------------- | ----------------------------------------------------------------------------------------- | --------------- |
| `onReady`     | It is executed when the SDK has been fully initialized.                                   | N/A             |
| `onCompleted` | It is executed when a payment is successfully completed.                                  | N/A             |
| `onError`     | It is executed when some type of error is found in the payment process or payment intent. | `error: string` |