KSeF Lighthouse – How to Automatically Check System Status

The Ministry of Finance has launched a public API called KSeF Lighthouse. It shows in real-time whether the system is operational, undergoing maintenance, or experiencing failures.

What is KSeF Lighthouse?

Lighthouse is a public API launched by the Ministry of Finance. It shows three things in real-time:

• Planned maintenance windows – system maintenance announced in advance
• Regular failures – unplanned KSeF issues
• Total failures – when even the Ministry of Finance website goes down

The API is available without authorization, so any system can automatically check if KSeF is operational. You can find it at https://www.gov.pl/web/kas/api-krajowego-system-e-faktur

How does it work?

Lighthouse continuously monitors KSeF and publishes information about its status. It works like a bulletin board – when something happens with the system, Lighthouse immediately displays it.

The goal is simple: so you don't have to guess whether KSeF is working. Instead of manually checking the Ministry's website, you can look at Lighthouse (or your accounting software can do it for you). You'll get a clear answer: operational, maintenance, or failure.

When there's a problem, Lighthouse shows details: from what time, what type, when it will end (if known). Everything in one place, always up-to-date.

Types of Events in Lighthouse

The system distinguishes three types of problems.

MAINTENANCE – Planned Downtime

The Ministry announces it in advance. The message includes the start and end date and time. Maintenance windows are usually at night or on weekends.

FAILURE – Outage

An unplanned problem. The system sends two messages: FAILURE_START when the outage begins and FAILURE_END when it's fixed. Initially, no one knows how long it will last, so the end is announced separately.

TOTAL_FAILURE – Complete Outage

KSeF and the Ministry's website stop working. Information is then communicated through television, radio, and news portals.

Who is this for?

Developers can add Lighthouse support to their systems. The API is public and doesn't require authorization. Integration takes a few hours. Clients will receive automatic notifications about KSeF issues.

Users choosing invoicing software can check if it supports Lighthouse. Such programs automatically inform about outages. No manual status checking required.

What's next?

If you use accounting software, check if it supports Lighthouse.

You can find more information in the documentation at github.com/CIRFMF/ksef-latarnia.