Stress again has Singularity Sky which has a minor character as a weakly godlike AI (which is explored much more as a character in the sequel Iron Sunrise (the third book in the series is not to be written - http://www.antipope.org/charlie/blog-static/2010/09/books-i-... ))
Implied Spaces by Walter Jon Williams (aside: it has a mention of the Vingean Singularity):
> “I and my confederates,” Aristide said, “did our best to prevent that degree of autonomy among artificial intelligences. We made the decision to turn away from the Vingean Singularity before most people even knew what it was. But—” He made a gesture with his hands as if dropping a ball. “—I claim no more than the average share of wisdom. We could have made mistakes.”
Accelerando Charles Stross https://www.antipope.org/charlie/blog-static/fiction/acceler...
Stress again has Singularity Sky which has a minor character as a weakly godlike AI (which is explored much more as a character in the sequel Iron Sunrise (the third book in the series is not to be written - http://www.antipope.org/charlie/blog-static/2010/09/books-i-... ))
Implied Spaces by Walter Jon Williams (aside: it has a mention of the Vingean Singularity):
> “I and my confederates,” Aristide said, “did our best to prevent that degree of autonomy among artificial intelligences. We made the decision to turn away from the Vingean Singularity before most people even knew what it was. But—” He made a gesture with his hands as if dropping a ball. “—I claim no more than the average share of wisdom. We could have made mistakes.”
There's the classic Asimov - The Last Answer
There's a nacesant one in True Names by Vinge (the post singularity in Marooned in Realtime doesn't have any AIs) https://ia801004.us.archive.org/0/items/truenamesvingevernor...
And digging fairly deep into my library, I'll also make mention of The Risen Empire by Scott Westerfeld.
There's a lot of smart AI in sci-fi - but things that that gets close to flirting with the singularity are indeed a rarity.