Medium launches TK, an AI assistant built into its writing app

The name refers to the publishing placeholder “TK,” used to mark information that will be added later. It stands for “to come,” with a K chosen because the rare letter combination makes the placeholder easy for proofreaders to spot. Medium gives it a new purpose: helping writers fill gaps as they develop a draft.

The company says TK can answer quick questions, bring back passages users previously saved and suggest prompts. Its planned editorial tools include feedback on headlines and ways to match drafts to the style guides of Medium publications. Writers can also share early drafts and receive feedback from other people through the app’s social features.

The launch comes amid concern in publishing and literature about whether AI assistance can cross into AI-generated writing. Authors have lost book deals over suspicions of AI use, and literary awards have faced scrutiny after winners were suspected of using AI. At the same time, questions remain about how reliably detection tools can distinguish writing produced by AI from writing made with its assistance.

Medium argues that AI can support rather than diminish writing, saying that “artificial intelligence makes writing more important, not less.” The company acknowledges risks including low-quality material and a blurred line between human- and AI-written work. TK will let authors publish notes explaining how they used AI. Medium said its goal is to make writing’s provenance “clear, transparent, and inspectable, right down to the prompting and source material.”

TK can also connect, optionally, to a user’s AI agent through its MCP server or Claude skill, giving the app access to projects and ideas stored in the agent’s memory. The web app is available now; a desktop version is on the roadmap. It supports Markdown import and export but is not itself a Markdown app. Writing is not encrypted, though users can control access to their work. Medium says TK is free for anyone with a Medium account.