How venfree handles your project files

When you open a project file in venfree, exactly three things happen: venfree loads the file into your browser memory. It then reads the structure to display your devices, rooms and functions. Finally, it transfers your planning to the open .venfree format.

What venfree does not do: write back to the original file or store it on a server. A .knxproj file exists only in your browser memory and is never touched again. You always export .venfree, never a modified .knxproj.

A .knxproj file contains more than just your planning. It also contains embedded product databases from device manufacturers: Siemens, MDT, Gira and others have stored their application programs there. This data belongs to the manufacturers.

venfree reads this data to display device names and functions to you. It does not extract or store it separately. What appears in the .venfree file is exclusively your planning decisions: which rooms, which functions, which devices you chose.

This is the same principle by which a PDF viewer may display a PDF without redistributing the manufacturer's fonts.

The .venfree format is openly specified and in the public domain (CC0). Anyone can read, write and implement it. No manufacturer can make it proprietary.

What a .venfree file contains is your planning: rooms, functions, chosen devices, prices at the time of planning. This data belongs to you. venfree is only the tool that creates it.

You can download your .venfree file, open it on another device, or send it to your electrician. Your planning work is not locked into venfree.

venfree parses .knxproj files on the basis of §69e UrhG (EU Software Directive Art. 6): the interoperability privilege allows analysing format structure for compatibility purposes. Parsing is limited to what is necessary: display and conversion to .venfree.

Writing back to the original format (.knxproj) is not implemented and will remain so until a separate legal review clears this step. The complete .venfree format specification including legal basis is available at legal/FORMAT-SPEC.md in the venfree repository.