Substack adds Pangram-powered AI detection across posts, notes, and comments

The Verge·medium signal

Substack is rolling out an AI-detection tool built on Pangram that scans posts, notes, replies, and comments to estimate whether text was machine-written. It is the first major newsletter platform to surface detection scores natively to readers rather than only using them for internal enforcement. The obvious tension: detection accuracy on well-edited hybrid human/AI writing remains poor, and Substack is putting a probabilistic number in front of readers as if it were a verdict.