---
title: "Implement callbacks with register_device_request"
url: "https://docs.adyen.com/point-of-sale/classic-library-deprecation/classic-library-integrations/c-library-integration/calls-and-callbacks-c-library/implement-callbacks-with-register_device_request"
source_url: "https://docs.adyen.com/point-of-sale/classic-library-deprecation/classic-library-integrations/c-library-integration/calls-and-callbacks-c-library/implement-callbacks-with-register_device_request.md"
canonical: "https://docs.adyen.com/point-of-sale/classic-library-deprecation/classic-library-integrations/c-library-integration/calls-and-callbacks-c-library/implement-callbacks-with-register_device_request"
last_modified: "2026-05-23T12:56:20+02:00"
language: "en"
---

# Implement callbacks with register\_device\_request

[View source](/point-of-sale/classic-library-deprecation/classic-library-integrations/c-library-integration/calls-and-callbacks-c-library/implement-callbacks-with-register_device_request.md)

## About this task

In the C Library integration, some callbacks are part of, and passed with, a `register_device_request`.

This includes:

* `ped_state_change_CB`
* `tender_additional_data_CB`
* `tender_print_receipt_CB`
* `tender_check_signature_CB`
* `tender_progress_CB`
* `tender_dcc_CB`
* `tender_finished_CB`
* `tender_referral_CB`

This does not apply to callbacks that are not added to the `register_device_request` structure.  For these callbacks, see [Implement callbacks](/point-of-sale/classic-library-deprecation/classic-library-integrations/c-library-integration/calls-and-callbacks-c-library/implement-callbacks).

We have defined a signature for each callback in the **register\_device\_extern.h** file. The signature we provide looks like:

```cpp
void tender_print_receipt_CB(receipts_strct * , ped_device_info * , void * );
```

You will need to implement callback functions with the same signature. 

## Steps

To use these callbacks:

1. Implement the callback. In the following example we will implement the `print_receipt` callback.

   ```cpp
   void tender_print_receipt_CB(receipts_strct * status_tender, ped_device_info * ped_state, void * echo_struct){

       app_context_t * sPOS = (app_context_t *)echo_struct;

       //TODO: store the receipts somewhere

       //ADYLibraryResult result =

       confirm_print_receipt(sPOS->terminal_id, sPOS->tender_reference, true);

   }
   ```

2. Assign a pointer for `print_receipt_callback`  to `status_tender_print_receipt` in the `callbacks` data structure within the `register_device_request`

   ```cpp
   register_device_request_ptr->callbacks.status_tender_print_receipt   = tender_print_receipt_CB;
   ```

3. When you have populated `register_device_request.callbacks` with each callback, pass `register_device_request` as a parameter of the `register_device` call.

   ```cpp
   ADYLibraryResult result = register_device(register_device_request_ptr, register_ped_CB, sPOS);
   ```