Development environment

API: (opens in a new tab)

Development environment is accessible publicly so nothing stands in your way to start integrating.

Development setup

  1. Install Qerko app
Qerko-AppStore (opens in a new tab)Qerko-GgStore (opens in a new tab)
  1. The app works in production mode by default. To switch the app between development and production mode, scan the QR codes from the default app screen. A red TEST mark will appear in the top part of the screen which indicates that the app has been switched to development mode.

Second option to switch environments is to log out, and log back in via e-mail method and use qerko-toggle-test as an adress.

  1. When the app is switched to development mode, you can register your development account and add a testing payment card.
Card numberExpirationCVC
4000 0070 0001 000612/24600

More ČSOB test cards (opens in a new tab)

PayU (SK, DE, AT)
Card numberExpirationCVC
5150 0300 9035 018612/29123

More PayU test cards (opens in a new tab)

Adyen (HU)
Card numberExpirationCVC
4111 1111 4555 114203/30737

More Adyen test cards (opens in a new tab)

For PayU and Adyen testing payments, contact our tech-support at in order to setup the testing gateway.

Payments are simulated, so feel free to pay anything.

  1. Register your development restaurant at Restaurant Admin (opens in a new tab). It will take you to restaurant creation form after the registration. Prefferably, use your POS name as a restaurant name. You can create any number of restaurants. Before payment testing, let our tech-support know, they will enable the necessary payment gateways for your testing restaurants.

  2. Create an API key. There is a link API keys admin in the left column (accessible by the icon in the top left corner on a smartphone).
    This key will be used on the "restaurant level" where each restaurant has its own key so it has to be editable in the POS by restaurant, or by POS vendor.

  3. All POS systems are required to use an POS-ID. This is a unique identifier for every vendor. In development environment, you can use any non-empty string.

  4. All set:

  • You have set up the app on your smartphone.
  • You have added the credit card into the app.
  • You have an API key for POS authorization.

Let’s roll.

Development tools

Qerko provides a few goodies which can be used for development and testing purposes.

Demo POS (opens in a new tab) (alias DEMO2)

This is a simple POS which serves as our testing environment. Feel free to use it to see how things work. DEMO2 uses websocket and current API v2.

API Tester (opens in a new tab)

This is a simple tool which sends requests to the API. Use it to test raw requests and responses.

API Key typo check

function verifyApiKey(apiKey: string): boolean {
	const KEY_LENGTH = 29;
	if (apiKey.length != KEY_LENGTH) {
		return false;
	const HASH_LENGTH = 4
	let base = apiKey.substr(0, apiKey.length - HASH_LENGTH);
	let hash = apiKey.substr(apiKey.length - HASH_LENGTH, HASH_LENGTH);
	return hex(sha1(base)).toLowerCase().startsWith(hash);

Production environment

API: (opens in a new tab)

Production environment works the same way as the development environment, but payments are not simulated any more. You have to make these steps to enter the production environment:

  1. Switch URL to production: (opens in a new tab)

  2. Start using production Pos-Id which will be assigned to you by tech-support at The process of assigning a production Pos-Id is mostly made up of testing the documented functionalities in the sandbox environment - having it tested on your own and ready for our testing will be greatly appreciated. We recommend hardcoding the Pos-Id into your POS or distributing the value with the POS. It is not supposed to be user configurable.

If your company develops multiple POS solutions, each one will be assigned a unique Pos-Id.