I think the first question is if we want to break backwards compatibility?

I lean to not breaking compatibility. If so, the other options are:

• keep the authors string using a different separator (for example, ";")
• keep the authors string and add a new array of author strings

keep the authors string and add a new array of author strings

I'd vote for keeping authors as is, and adding (something like) author_list as the array of author strings to keep backward compatibility.

From a cursory search, it seems the vast majority of instances of peps.json in the wild are reproductions of the 723 example:

https://github.com/search?q=%22https%3A%2F%2Fpeps.python.org%2Fapi%2Fpeps.json%22+NOT+is%3Afork+NOT+is%3Aarchived&type=code

But sure, happy to add as a new field. The only negative would be the file size (~15% increase).

A