The app's central feature is an AI assistant that can be activated from within a draft by typing "@TK." Instead of switching to another application to look up information or retrieve previous notes, writers can ask questions while continuing to work in the same editor.
For example, a user can ask the assistant to check a date or locate a passage written earlier. The feature takes its name from the journalism convention of using "TK" to mark information that needs to be added later.
Medium says the approach is intended to reduce interruptions that can occur when writers stop drafting to research details or search through previous material.
TK also includes tools for capturing and importing ideas. Users can access a mobile app and widgets for recording text or voice notes, transfer their existing Medium writing, and import material from note-taking applications such as Bear and Obsidian. The app also supports contributions from external AI agents, allowing tools such as Claude to store research in a user's notebook.
Beyond retrieving information, TK offers AI-powered editorial feedback intended to help writers improve their drafts. Its built-in capabilities include reviewing headlines, providing editing suggestions, and comparing drafts with the editorial guidelines of Medium publications.
The system can also identify when a collection of writing might be suitable for development into a book. These features are designed to provide feedback while leaving the underlying writing and decision-making to the user.
Medium is pairing those AI capabilities with a collaborative feature called social libraries. These spaces allow writers to share work with others, exchange feedback, and develop projects within a shared environment.
The company has introduced three open libraries to demonstrate the feature. Public Journal provides a space for regular personal writing, Get Feedback on Your Writing allows users to share unfinished drafts, and Write a Book supports writers working toward a self-published book.
The combination of AI assistance and human feedback reflects Medium's stated emphasis on preserving the personal nature of writing.
“We’re not anti-AI, we’re pro-human—and that’s why we built TK, a new app from Medium,” Stubblebine wrote in the announcement.
Another major component of TK is its ability to organize and retrieve information from a user's existing writing. Rather than requiring people to maintain a detailed filing system, the app is designed to recognize connections between notes and bring relevant material back into view.
Writing prompts can draw on previously saved content, helping users revisit unfinished ideas or expand on earlier observations. TK can also generate wiki-style summaries from searches, topics, tags, or libraries, creating overviews of recurring themes and linking them to the original notes.
Medium is extending those capabilities beyond the app through integrations with AI agents. TK includes a Model Context Protocol (MCP) server and a Claude skill, allowing compatible AI tools to access information stored in a user's notebook.
The integrations are intended to give AI assistants access to a person's accumulated research, projects, opinions, and unfinished work. Rather than relying exclusively on general information, an agent can use the context a writer has collected over time.
That functionality distinguishes TK from writing tools centered primarily on producing or polishing individual documents. Medium is building the app around the idea that personal writing can serve as a reusable source of information for future projects and AI-assisted workflows.
The launch also represents an expansion of Medium's role beyond publishing completed articles. TK introduces a separate environment for the earlier stages of writing, including idea collection, research, drafting, and private collaboration.
Medium has not detailed pricing or provided specific adoption targets in its announcement. The company also has not specified whether AI-assisted writing created in TK will require disclosure when published.
For now, TK brings together writing, note management, editorial assistance, and AI integrations in a single application. Medium's approach emphasizes helping users develop and reuse their own ideas, with AI serving as a supporting tool throughout that process rather than taking over the work of writing.
This analysis is based on reporting from Medium & the tech buzz.
Image courtesy of Medium.
This article was generated with AI assistance and reviewed for accuracy and quality.
