ksef-cli

A command-line tool for submitting invoices to KSeF (Krajowy System e-Faktur, Poland's national e-invoicing system), API 2.0.

You provide a ready FA(3) invoice XML file. ksef then logs in with a token, encrypts the invoice, submits it and waits until KSeF accepts it.

At the end it saves the UPO receipt next to the invoice and prints the KSeF number together with a public verification link.

The tool does not create invoices from scratch!

Features

• Submits a ready FA(3) XML and saves the UPO as invoice.upo.xml
• Prints the KSeF number and the invoice's public link
• Lists the invoices issued in a given year and downloads them from KSeF
• Works with the test, demo and production environments
• Converts an Invoify invoice (JSON or XML export) into an FA(3) XML for VAT-exempt sellers (art. 113)
• For foreign-currency invoices, fetches the mid rate from NBP's public API

Installation

You need Go 1.26 or newer.

go install codeberg.org/piotrkrzysztof/ksef-cli/cmd/ksef@latest

The command installs the ksef program in ~/go/bin.

Getting started

You need Go 1.26 or newer and a token from the KSeF taxpayer app (Aplikacja Podatnika KSeF, "Tokeny" tab).

export KSEF_TOKEN='...'    # token from the taxpayer app
ksef init test             # creates ~/.config/ksef.conf
ksef selfcheck             # checks encryption and login
ksef send invoice.xml      # submits the invoice, saves invoice.upo.xml
ksef list                  # invoices issued this year
ksef pull KSEF_NUMBER      # downloads an invoice as stored in KSeF

Start with the test environment. Switch to production only after you have verified on the test instance that everything is correct.

Keep in mind that every entry in production KSeF has legal consequences. According to a statement by the Ministry of Finance, financial penalties for mistakes in using the system will not be enforced until the end of 2027. Issuing invoices in KSeF is nevertheless mandatory from 1 January 2027 for all businesses, regardless of their turnover.