Alibre Design file format

Question

Did anyone try to read programmatically an Alibre Design CAD file?
I see that deep inside a part file (*.AD_PRT) there's an STEP/ISO 10303-21 structure, but I'm wondering about the rest of the file.. Is it proprietary?

Answer 1

Alibre product manager told me (via email) that currently there's no "open" specification for AD_PRT files (and it looks like the format changes fairly often)

Answer 2

I would expect the rest of the file to be proprietary. But if geometry is all you want, then the STEP file stream is probably enough.