Medium Opens TK Notebook to Writers with Inline AI Assistance

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 executive Tony Stubblebine’s shorthand for the division is “TK is the gym and Medium is the stage.”

The first version includes a mobile app and widgets for voice and text capture, imports of Medium archives and Bear or Obsidian vaults, and Markdown import and export. It ships without a native desktop app, which Stubblebine said Medium wants to add.

AI Assistance Inside the Draft

Writers can type @TK in the middle of a sentence to check a fact or retrieve earlier writing without leaving the editor. The name adapts the publishing placeholder TK, meaning “to come,” which writers traditionally leave for unfinished information. Here, the placeholder can trigger the assistant instead, keeping research and retrieval from interrupting the draft.

AI feedback covers editorial and headline suggestions, can compare drafts with Medium publications’ style guides, and can flag material that could be organized into a book. Medium says TK will not write a user’s essay, positioning the assistant as support for the writer’s own work rather than a substitute for it.

TK also creates a writing prompt each morning, which can refer back to earlier notes. Searches, topics, tags and libraries can be turned into wiki-style summaries with themes, key ideas and links to the underlying notes, giving an unstructured archive a route back into later drafts.

Agents, Sharing and Provenance

Beyond its built-in assistant, TK includes an MCP server and Claude skill so agents can draw on a user’s stored positions, projects and unfinished ideas. Medium’s Claude Daily Note plugin shows how that connection works: with TK’s MCP server connected in Claude Cowork or Claude Code, the plugin creates one document per day, updates it in place and carries unchecked to-do items forward. Its targeted edit operations are designed to preserve live edits, existing checkbox states and the user’s writing.

Not all feedback is automated. Social libraries let writers share drafts with groups, including open libraries for public journaling, feedback before publication and developing a self-published book. Notes otherwise remain private, with user-controlled access permissions, and Medium states that no AI company trains on or uses a person’s writing without permission.

Published TK notes can also disclose which material was human-written and which was AI-written, with provenance inspectable down to prompts and source material.

Writing Habits Behind the Design

Medium’s State of Writing Report 2026 supplies context for those choices. In its Harris Poll survey, 71% of surveyed writers had used AI as part of their writing practice in the previous three months, but 60% distrusted their own AI-produced writing and 69% distrusted such writing from others. The Harris Poll conducted the online US survey for Medium from August 12–17, 2026 among 1,175 writers, with full-sample precision of 4.0 percentage points using a 95% Bayesian credible interval.

The report also counted 4.4 million unpublished drafts written on Medium over the preceding year. That behavior helps explain why TK treats private writing as the default and sharing as a later decision, while its provenance tools address the distrust that accompanies AI use.

For Medium, TK extends its role from hosting published work into the private process that precedes it. The product’s division of labor is also its answer to the survey’s tension: AI can check, retrieve, summarize and critique, while the writer keeps authorship and controls how much of that process is disclosed.