Medium launches free TK AI writing assistant for the web

By Sophie Lindqvist

Medium launched TK on Monday as a free web-based AI writing assistant for people with a Medium account, with a desktop app on its roadmap. TK embeds an assistant inside the editor. Writers summon it by typing “@TK” followed by a request or prompt.

The name carries publishing shorthand. “TK” means “to come,” a placeholder for missing information. Medium chose K instead of C because few English words contain “tk,” which makes the placeholder stand out more easily in written text for proofreaders to catch.

What does Medium say about disclosing AI use?

Medium acknowledges that AI can produce low-quality content. The company also recognizes the difficulty of separating human writing from AI assistance. TK lets authors publish notes explaining transparently how they used AI.

Medium explained in its launch post: “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.” It says that clarity should extend down to the prompting and source material.

Medium also says “artificial intelligence makes writing more important, not less.” It describes AI as able to amplify human intelligence, with the written word as its foundation.

For practitioners, the notes can answer a reader’s first question: how much of the draft involved AI? They cannot resolve authorship disputes or guarantee reliable AI detection.

What can TK do inside the editor?

Medium says TK can answer factual questions, including how many days a month contains, and retrieve earlier writing saved during idea development without requiring another browser tab. The app also organizes previous writing and suggests writing prompts.

Medium says TK will ship with editorial feedback, headline feedback and style-guide matching for Medium publications. Those skills work on the draft.

For practitioners, that could shorten research and revision cycles. The announcement offers no accuracy rate, user count or measured time saving, so those benefits remain untested.

TK also adds a social layer for human feedback. Writers can share early drafts with other people and collect responses before publication.

How does TK connect to outside tools?

Medium says TK can optionally connect to a writer’s own AI agent through its MCP server or Claude skill, adding context from projects, stated positions and the agent’s memory.

TK imports and exports Markdown, but Medium says it is not a Markdown app itself. Writing remains unencrypted because Medium designed the product for collaboration. Users can set access-control permissions on their work instead.

That makes access settings part of the publishing workflow, rather than an afterthought. The launch announcement gives no default permission model or encryption standard.

Why is the launch controversial?

The product enters publishing already confronting questions about AI-generated long-form prose. Multiple authors have reportedly lost book deals over suspicions of AI assistance. Other literary awards have faced scrutiny over suspected AI-assisted winners.

Those cases involve allegations rather than a universal finding about one tool. The launch material does not name the authors, publishers or awards involved.

Writers have long used automated proofreading and light grammatical edits. The newer concern centers on editorial suggestions becoming the writing itself, rather than reflecting a writer’s own thinking.

Detection tools face their own uncertainty because AI models train on human writing. That makes it harder to determine whether a text was fully human-written, AI-assisted or something else. Medium’s disclosure notes address transparency, not the limits of detection.

Who can use TK, and what comes next?

At launch, TK works on the web for people with a Medium account. Medium describes the company as profitable and makes TK free. The announcement gives no desktop release date, user target or revenue forecast.

That leaves adoption, engagement and workflow savings unmeasured. For practitioners, the immediate trade-off is no TK fee, alongside unencrypted writing and no published accuracy benchmark.

TK could become a standard early-stage tool if its disclosure tools and human feedback prove useful. The next test is whether writers keep using it when readers can inspect how AI shaped the draft.