An autobiography is not a novel, because it lacks the fundamental aspect of being fictional.
There is such a thing as an autobiographical novel, but that is not nonfiction.
Because novels are, by definition, works of fiction.
The closest thing to a ‘nonfiction novel’ is probably the historical novel, which is a fictionalized historical account… but I’m not sure why such a thing would particularly be suited to this summarization methodology.
"Fictional narrative: Fictionality is most commonly cited as distinguishing novels from historiography. However this can be a problematic criterion.
...
Several novels, for example Ông cố vấn written by Hữu Mai, were designed to be and defined as a "non-fiction" novel which purposefully recorded historical facts in the form of a novel.":
