Write with AI and still know which words are yours

mrkdwn guide · Based on mrkdwn 1.5 · September 18, 2026

Asking a model to help with a draft is easy. What is hard is what happens six months later, when you reread the draft and cannot tell which sentences you wrote. mrkdwn is built around that problem. The assistant is there when you call it, and it leaves a record of what it did. This guide covers how to call it, how to review what it offers, and how to see afterwards who wrote what.

Call it where the cursor is

There are three slash commands, and each one works at the cursor:

/continue drafts the next few sentences from where you stopped.
/rewrite offers another version of the selection.
/summarize condenses the selection or the note.

Nothing runs until you type one of them. The editor does not finish your sentences, does not suggest while you type, and does not change your text in the background.

Review a diff before anything lands

Whatever the model returns comes back as a diff: what it would remove, and what it would add in its place. Nothing reaches the document until you accept it. Discard it and the note is exactly as it was.

Read the diff the way you would read a colleague’s edit. The useful question is not whether the new version is better. It is whether it still sounds like you. A rewrite that fixes the rhythm but swaps in a word you would never use is worth taking only in part. Accept it, then change that word back.

See who wrote what

Authorship tracking keeps a record of where each passage came from: typed, pasted, generated, imported, or quoted as a reference. Turn on Show Authors and the text is tinted by source, so a paragraph that is half yours and half the model’s reads that way on screen.

You can also set it by hand. Select a passage and mark it as Human, AI or Reference. That is useful for text that arrived by some route the app could not see, like a quotation you typed out yourself or a paragraph you drafted in a chat window and pasted in.

Each AI agent gets its own colour, built from that vendor’s brand colour and balanced so that no single agent stands out more than the others. Quoted sources get a quieter colour of their own. Document statistics break the note down by author, so you can see at a glance how much of it is yours. The marks sync between your devices along with the note.

Choose where the model runs

mrkdwn supports two options.

Claude, with your own API key. You add the key in Settings. It is stored in the system Keychain on that device only, and is not synced or backed up. Only the text you send with a command goes to the API, and only when you send it.
Apple’s on-device model. It needs no key, and nothing leaves the device. It needs macOS 26 or iOS 26, Apple silicon, and Apple Intelligence switched on.

Everything else in mrkdwn works offline. The AI is the only part that can need a network, and with the on-device model even that does not.

Let the editor point, and do the fixing yourself

Two tools help you look harder at a draft without writing anything for you.

Style check flags adjectives, adverbs and passive voice. It marks them and never corrects them. A flag is information, not an instruction, and plenty of adverbs deserve to stay.
Prose highlighting colours each part of speech, so you can see the shape of a sentence: where the verbs are, and how many nouns are stacked up in front of one.

Both stay off until you switch them on. They are for revision, not drafting.

A workflow that keeps the draft yours

One way to put this together:

Draft with the assistant off. Get the argument down in your own words, however rough.
Revise with style check on. Deal with the flags you agree with, and ignore the rest.
Call the assistant on the stuck parts only. Use /rewrite on the paragraph that will not come right, and read the diff line by line.
Check the authorship tint before you publish. If more of the page is tinted than you expected, you know where to look.

The aim is not to avoid AI. It is to keep being able to answer, honestly, which parts you wrote.

Where to go next

mrkdwn is on the App Store for iPhone and iPad. The Mac app is still in pre-release testing. See where each platform stands.