OneHub eKasa – Introduction

About

OneHub eKasa application is a fiscal service running on our devices, and is certified by Slovak government as an eKasa client.
It allows you to print fiscal and non-fiscal documents in legally compliant way.

What is eKasa?

In Slovakia, all fiscal documents (receipts, invoice payments in cash, etc.) must be registered in what’s called „Online Registračná Pokladnica“ (ORP), or Online Cash Register in English.
The ORP must send these documents to a system called „eKasa“, operated by the Slovak government.
The software must also guarantee that these fiscal documents are stored in a certified non-erasable memory, called „chránené dátové úložisko“ (CHDÚ), or protected data storage in English.

OneHub eKasa software meets all this criteria and more, dealing with the complicated stuff and certifications, providing integrators with an open API, so that they can focus on the more important stuff – like making great ECR SW.

What can OneHub eKasa service do?

OneHub eKasa provides you with a support for the following tasks:

  • Registration of fiscal documents (receipts, invoice payments)

    OneHub eKasa does the following:

    • storage of documents in certified protected data storage
    • sending of documents to eKasa system
    • formatting & printing of documents

    ECR software does the following:

    • Putting together the list of items on the receipt, list of payments, etc.
    • Dealing with card payments (separate integration – see payment docs)
    • Providing additional text to print in header of footer, choosing text size

  • Registration of current cash register location

    OneHub eKasa does the following:

    • storage of location updates in certified protected data storage
    • sending of location updates to eKasa system

    ECR software does the following:

    • obtaining cash register’s location (address, GPS, or similar)

  • Registration of cash movements in the cash drawer (deposits, withdrawals)
    Note: this is optional according to current Slovak law.

    OneHub eKasa does the following:

    • storage of cash movements in certified protected data storage
    • sending of cash movements to eKasa system

    ECR software does the following:

    • Keeps track of cash register state, including (optionally) individual banknotes, coins, etc.

How can you communicate with OneHub eKasa?

OneHub eKasa supports HTTP/JSON communication on port 12412.

You can either communicate with the service directly (over local area networks),
or if such communication is not possible due to physical/networking constraints (e.g. your ECR software running in a cloud, and has no access to merchant’s local area network), optionally by forwarding these requests via OneHub Cloud.

Protocol: OneHub eKasa API documentation.

Local Area Network communication

If your software is running on a device connected to the same local area network as the device running OneHub eKasa service, you can communicate directly over TCP/IP (that local network).

This is always preferred, as it removes a potential point of failure, the internet connection at the site, allowing the system to operate even offline.

It’s important to make sure the eKasa device is using a static local IP address, as IPs assigned automatically by DHCP server (by the router) can change over time, which would result in your software no longer being able to communicate with our device, until settings in your software are updated.

Static IP can be configured in either of these two ways:

  • Configuring static IP on the device
  • Configuring static IP using WiFi router’s DHCP server

Cloud communication

OneHub Cloud provides you with an HTTP request forwarding API.
You simply send the request from anywhere to our cloud, and we’ll make sure it gets delivered to the device, no matter what kind of private network or VPN it’s behind.

Since this only works when the device has internet access (to reach our cloud), any sort of internet outage will result in your integration not working!
You should always use local area network communication whenever possible, especially if your software needs to work in offline mode, like a cash register for example.

This integration path is more complicated, as it involves implementing multiple cloud APIs in order to find the correct device you want to communicate with in the cloud, and then the HTTP request forwarding API itself.

You can learn more in the HTTP Request Forwarding API documentation.

Additional resources

    • How rounding of cash payments works and how payments are to be declared on documents
    • VAT rate changes since January 2025