---
title: "Open source: Quittio under the MIT licence"
description: "Quittio is open core: the core, the Laravel integration and the German country pack are MIT licensed. Packages, repositories and how to contribute."
canonical_url: "https://quittio.dev/en/open-source"
locale: en
meta:
  "og:description": "Quittio is open core: the core, the Laravel integration and the German country pack are MIT licensed. Packages, repositories and how to contribute."
  "og:image": "https://quittio.dev/og/quittio-en.jpg"
  "og:image:alt": "Quittio: Invoices, settled. E-invoicing for PHP and Laravel, with a validated sample invoice."
  "og:image:height": "630"
  "og:image:type": image/jpeg
  "og:image:width": "1200"
  "og:title": "Open source: Quittio under the MIT licence"
  "twitter:image": "https://quittio.dev/og/quittio-en.jpg"
  "twitter:image:alt": "Quittio: Invoices, settled. E-invoicing for PHP and Laravel, with a validated sample invoice."
---

> Index of every page on this site: [llms.txt](https://quittio.dev/llms.txt)

# Open source. And it stays that way.

Creating, validating, reading and rendering e-invoices is free: the core, the Laravel integration and the German country pack are MIT licensed. Quittio Managed funds the maintenance.

[**Quittio on GitHub**](https://github.com/Quittio/quittio) [**Packagist**](https://packagist.org/packages/quittio/quittio)

## Packages

| **Package** | **Content** | **Links** |
| --- | --- | --- |
| quittio/quittio | Everything in one package for Laravel: core, Laravel integration and the German country pack. | [GitHub](https://github.com/Quittio/quittio) · [Packagist](https://packagist.org/packages/quittio/quittio) |
| quittio/core | Country-neutral core: EN 16931 data model, calculation, CII and UBL, ZUGFeRD/Factur-X, validation. Works without Laravel. | [GitHub](https://github.com/Quittio/core) · [Packagist](https://packagist.org/packages/quittio/core) |
| quittio/laravel | Laravel integration: facade, configuration, Blade templates, Artisan commands, testing helpers. | [GitHub](https://github.com/Quittio/laravel) · [Packagist](https://packagist.org/packages/quittio/laravel) |
| quittio/country-de | Country pack for Germany: mandatory fields under the VAT Act, tax presets, XRechnung, BR-DE rules, DIN 5008. | [GitHub](https://github.com/Quittio/country-de) · [Packagist](https://packagist.org/packages/quittio/country-de) |

Development happens in the monorepo [Quittio/quittio](https://github.com/Quittio/quittio). The single packages are read-only copies; issues and pull requests belong in the monorepo.

## Quality you can check

- ### PHPStan at level max

  Static analysis at the highest level.
- ### Pest tests

  Unit, scenario and concurrency tests.
- ### Official validators in CI

  All fixtures run through KoSIT and veraPDF.
- ### Visual regression

  PDFs are compared as images against references.

## Contribute

### Report a bug

Ideally with version, steps and a sample invoice.

[**Issues**](https://github.com/Quittio/quittio/issues)

### Contribute code

Tests with Pest, PHPStan at level max, code style with Pint.

[**Contributing**](https://github.com/Quittio/quittio/blob/master/CONTRIBUTING.md)

### Write a country pack

Mandatory fields, tax presets and rules for your country.

[**Country packs**](https://docs.quittio.dev/country-packs)

Please do not report security issues publicly; follow the steps under [Security](https://quittio.dev/en/security) instead.

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```