There is another feature request for Can we have a "show post source" button?. That one is for the post itself, rather than the revision history. Perhaps it would be useful to have both? A "show source" or "raw text" button on a post, and a similar button on each entry in the revision history.

This would be showing raw Markdown (or HTML or MathJax depending on what the post author chose). Is this useful for your purposes or would you want just the text without any markup?

I want the raw Markdown/etc. (the actual post source), yes.

There's also some discussion of scraping in Is it okay to scrape Codidact for personal tools? and I've mentioned an API as an alternative approach. Would an API providing raw source text be relevant to your purposes? If so it would be good to get your input on what requirements you'd have (for this specific purpose and for an API in general). I might make a separate Meta post about what people want to see in an API.

Oh, it was just a one-off task to back up an edit history for something I already posted. In the future I plan to have a workflow where I save things locally first, so it won't be a problem anyway.

That said, I can definitely see the utility of such an API in general and I would definitely encourage you to make that post!

Meta discussion started: How should a Codidact public API work? .