> For the complete documentation index, see [llms.txt](https://developers.portos.sk/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://developers.portos.sk/previous-versions/legacy-documentation.md).

# Legacy documentation

To view documentation for PORTOS version 2.X and older (formerly known as *mPOS* Cash Register system), please see the legacy documentation at <https://mpos2api.docs.apiary.io>.