> ## Documentation Index
> Fetch the complete documentation index at: https://docs.bango.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Callbacks and notifications

> Asynchronous actions and communication by the Bango Platform

The Bango Payment API is a RESTful API: you make requests, and the Bango Platform returns responses. In some cases you might require out-of-band actions or communication from the Bango Platform, without an explicit request from your store.

The Bango Platform supports this in two ways:

* **Callbacks**: Automatic redirection of the user to a URL of your choosing at the end of a web-based identification or transaction flow. Bango adds query parameters to help you identify the reason for the redirection.
* **Notifications**: `POST` requests from the Bango Platform to a URL of your choosing at the conclusion of an identification session or transaction authorization, where a web-based identification or transaction flow was used. Bango includes body parameters to help you identify the reason for the notification.

Callbacks and notifications are similar but have important differences.

| Callback | Notification |
| - | - |
| Callback URLs are for **users** | Notification URLs are for **servers** |
| A callback URL references a web page that can be displayed to a user | A notification URL is a data transfer mechanism for server-to-server communication |
| Callbacks include parameters in the query string | Notifications include parameters in the `POST` body |

You can include custom query parameters in both callback URLs and notification URLs. However, some parameters are reserved: see [Bango Payment / Merchant API reference / API reference overview](/legacy/dcb-payments-v5/api-reference/index) for the details.