# Callbacks

Controlling a call from your application backend is done by responding to callbacks from the Sinch platform and/or by calling REST APIs in the Sinch platform from your application's backend.

Read more about how callbacks work [here](https://developers.sinch.com/docs/voice/api-reference/callbacks).

## Incoming Call Event

 - [POST ice](https://developers.sinch.com/docs/voice/api-reference/voice/callbacks/ice.md): When a call reaches the Sinch platform, the system makes a POST request to the specified calling callback URL.

This event, called the ICE event, can be triggered by either an incoming data call or an incoming PSTN call. Look here for allowed instructions and actions.

If there is no response to the callback within the timeout period, an error message is played, and the call is disconnected.

## Answered Call Event

 - [POST ace](https://developers.sinch.com/docs/voice/api-reference/voice/callbacks/ace.md): This callback is made when the call is picked up by the callee (person receiving the call). It's a POST request to the specified calling callback URL. Look here for allowed instructions and actions.

If there is no response to the callback within the timeout period, the call is connected.

If you have Answering Machine Detection (AMD) enabled, the amd object will also be present on ACE callbacks.

Note: ACE Callbacks are not issued for InApp Calls (destination: username), only PSTN and SIP calls.

## Disconnected Call Event

 - [POST dice](https://developers.sinch.com/docs/voice/api-reference/voice/callbacks/dice.md): This callback is made when the call is disconnected. It's a POST request to the specified calling callback URL. This event doesn't support instructions and only supports the hangup action.

## Prompt Input Event

 - [POST pie](https://developers.sinch.com/docs/voice/api-reference/voice/callbacks/pie.md): This callback is triggered as a result of a runMenu action. It can be triggered from either a user pressing a number of DTMF digits, or by the return command.

It's a POST request to the specified calling callback URL. Your application can respond with SVAML logic.

Note: PIE callbacks are not issued for DATA Calls, only PSTN and SIP calls.

## Notification Event

 - [POST notify](https://developers.sinch.com/docs/voice/api-reference/voice/callbacks/notify.md): This is the general callback used to send notifications. It's a POST request to the specified calling callback URL.

If there is no response to the callback within the timeout period, the notification is discarded.