Medium’s TK puts an AI assistant inside the writing process

By Rebecca Stone

Medium launched TK on Monday as a free web app for account holders, letting a writer summon an AI assistant inside a draft with “@TK”; desktop support remains on the roadmap.

The command reaches the draft through a deliberately familiar shorthand. A writer types “@TK” followed by a request, and the assistant responds inside the same document rather than sending the user to another browser tab.

Medium says TK can answer quick factual questions—its example is how many days a month contains—and retrieve earlier writing saved in the app while an idea develops.

That command name is a piece of publishing shorthand with a built-in edge. “TK” means “to come,” a placeholder journalists and other writers use for missing information. Medium substitutes K for C because English contains few words with the “tk” sequence, making the marker easier for proofreaders to spot. Inside TK, that blank becomes the feature.

What can TK do inside a draft?

Medium says TK will ship with dedicated skills for editorial feedback and headline feedback, plus functions that can compare a draft with the style guide for Medium publications. The skills sit inside the same drafting flow, beside the @TK command.

Medium also says TK will help users remember and organize material they wrote previously and suggest prompts for new work. Writers may optionally connect their own AI agent through TK’s MCP server or a Claude skill. In that setup, Medium says, the app can draw on a writer’s projects, positions and other ideas stored in the agent’s memory.

Why is AI assistance contentious?

TK lands in publishing while authors and literary institutions are already disputing how much AI belongs in long-form work. Multiple authors have lost book deals after suspicions that they used AI to help write them, and some literary awards have faced scrutiny after winners were suspected of relying on AI assistance.

The concern is not confined to fully generated prose. Writers have used automated proofreading and light grammatical editing for years, but editorial “suggestions” can migrate into the finished text until they begin to represent the author’s own thinking.

AI detectors add another layer of uncertainty: because models train on human writing, detection tools struggle to distinguish human work with AI assistance from human work with no assistance.

Medium takes the side that distinctions among AI-generated, AI-assisted and unassisted writing will no longer matter in the end. The company argues that AI makes writing more important, not less, and says, “AI is a technology that has the power to amplify human intelligence and it uses the written word as a foundation.”

How will Medium disclose AI use?

Medium does concede two risks: AI can produce low-quality content, and it can blur the line between human and AI writing. Its answer is disclosure attached to publication. TK lets authors add notes that explain how they used AI in a piece, turning the controversy toward traceability rather than concealment.

In a launch blog post, Medium said: “This is a start of what we believe is required to publish in the AI era, which is to make the provenance of writing clear, transparent, and inspectable, right down to the prompting and source material.”

What changes at launch?

TK also adds a social layer. Authors can share early drafts with other people and collect human feedback inside the app, giving the workflow a path from private drafting to communal review without requiring the document to leave TK.

TK becomes social, but several launch boundaries remain. It launched on the web, imports and exports Markdown, and is not, in Medium’s description, a Markdown app. A desktop application is on the roadmap, but the company gives no release date.

Writing in TK is not encrypted because the application is designed for collaboration. Users can set access-control permissions on their work, allowing authors to restrict access to shared drafts.

Medium, which is profitable, says TK will be a free tool for people with a Medium account.

With TK free for Medium accounts, its adoption will depend on whether writers trust its editorial and headline suggestions—and its provenance notes—more than AI-detection tools to separate assistance from authorship.