Alan Kay described [1] what he considers the first object oriented system, made in the 60s by an unknown programmer. It was a tape-based storage system, where the "format" of the tap was a set of routines to read, write, etc. at a known offsets on the tape.

So, prior art! :)

[1] https://www.cs.tufts.edu/comp/150FP/archive/alan-kay/smallta... (page 4)