During file uploading and page creation, maximum article size is not enforced and can be exceeded as demonstrated by example [1] (many others) on Commons Wikimedia.
Example 1 when editing original revision displays:
"Error: The text you have submitted is 2,106.545 kilobytes long, which is longer than the maximum of 2,048 kilobytes. It cannot be saved."
Has anyone seen the same behaviour when posting via the API, or does this not happen?
I mentioned this task at c:COM:VP#Files with too big wikitext. We need sanity checking on both Flickr2Commons and whatever it uses to upload.
The title of this report is incorrect if taken literally: there are some ways one can circumvent the limit, but it's not about page creation in general.
For instance Wikibase did not respect the limit until T119753 was fixed and I think many years ago we fixed this bug (tilde expansion not being counted) but I can't find the report right now:
https://pvx.fandom.com/wiki/User_talk:PVX-Misfate?offset=20071116000000&limit=20&action=history