Medium announced on November 9, 2026 that TK, its private notebook and writing app, is free with a Medium account after an invite-only phase. The app embeds an @TK assistant in the editor and includes AI feedback, archive organization and connections to personal AI agents. The wider opening follows Medium’s September 16, 2026 post, which described TK as invite-only or available to Friends of Medium while broader access was being prepared. TK is separate from Medium’s publishing platform; chief…