Can this be used to detect fonts used in a keynote file?

[Rahul Dutt Sharma]

also, how did u get to have such detailed info of the document format, is it documented anywhere else??

[Peter Sobot]

This isn't an issue, but yes, you could parse the Yaml produced by this library to get font information.

And a link to more detailed documentation is literally included in the readme:

keynote-parser was built by Peter Sobot but heavily based on prior work by Sean Patrick O'Brien.