Medium launches TK, an AI writing assistant built into the editor

Medium builds an AI assistant into the editor

Medium has launched a new app called TK that places an AI assistant directly inside the writing editor. According to TechCrunch, writers invoke it by typing "@TK" followed by a request or prompt, without leaving the draft they are working on.

The name is a nod to newsroom jargon. In publishing, "TK" is a placeholder meaning "to come" — deliberately spelled with a K because that letter pair is so rare in English that proofreaders can spot it easily in a manuscript. Medium is repurposing the marker as the thing that fills the gaps.

What the assistant can do

Per TechCrunch's report, TK can handle quick lookups that would otherwise send a writer to another browser tab, such as checking how many days a month has. It can pull in fragments the user saved earlier while fleshing out ideas, and it ships with skills for editorial feedback, headline feedback, and matching a draft to the style guide of Medium publications. The app also suggests writing prompts and helps writers organize what they have written before.

Beyond the built-in assistant, TK can optionally connect to a user's own AI agent through an MCP server or a Claude skill, so the agent's memory of a writer's projects and positions can inform suggestions. There is a social layer as well: writers can share early drafts with other people and gather human feedback.

A transparency answer to the AI-writing debate

TechCrunch frames the launch against an ongoing reckoning in publishing over AI-generated prose: authors have lost book deals over suspicions they used AI, and literary awards have come under scrutiny after winners were suspected of AI assistance. A persistent worry is that an assistant's editorial suggestions can quietly become the writing itself, while AI detection tools remain unreliable at telling AI-written text apart from AI-assisted text.

Medium's response is to lean in while adding provenance. The company argues that "artificial intelligence makes writing more important, not less," as quoted by TechCrunch, and TK lets authors attach notes to published work explaining how AI was involved. In a blog post cited by TechCrunch, Medium described this as the start of what publishing in the AI era requires: making the provenance of writing "clear, transparent, and inspectable, right down to the prompting and source material."

Availability and pricing

TK is available on the web at launch, with a desktop app on the roadmap. It imports and exports Markdown, though TechCrunch notes it is not a Markdown app itself. Writing in TK is not encrypted, since the app is designed for collaboration, but users can set access-control permissions on their work. The tool is free for anyone with a Medium account, and the company — which says it is profitable — has not announced paid tiers.

Why it matters

Most AI writing tools sit beside the editor or generate text on demand. TK embeds assistance into the drafting loop itself, normalizing AI as part of the writing surface rather than a separate step. Just as significant is Medium's provenance bet: rather than policing AI use, it is asking writers to disclose it, down to prompts and source material. If that convention catches on, it could shape how platforms and readers treat the boundary between human and machine-assisted writing — at a moment when detection tools cannot reliably draw that line themselves.