Autocomplete that never leaves your Mac

The chatbot tax

Most "AI writing" today means leaving what you're doing: open ChatGPT, type a prompt, wait, copy the answer, paste it back, then fix the parts that don't sound like you. That round trip is the tax you pay on every assisted sentence. For the short, frequent writing — emails, Slack replies, quick notes — the tax is bigger than the help.

Cotypist removes the round trip. It sits quietly inside whatever app you're already in and finishes your sentences as you type.

What Cotypist does differently

As you type, a faint grey suggestion appears ahead of your cursor — the rest of the sentence it thinks you're reaching for. If it's right, you press Tab to take one word, or ~ to accept the whole thing. If it's wrong, you keep typing and it disappears. No prompt, no chat window, no copy-paste.

Two things make it stand out.

It runs entirely on your Mac. The AI model lives on your machine, not in the cloud. Your words never leave the device — which means it works on a plane with no signal, and it means whatever you're writing (client names, half-formed ideas, private notes) stays private by design. macOS even stops it from reading password fields automatically.

It learns to sound like you. The more you write, the more it picks up your vocabulary, your names, and the way you phrase things. The goal isn't to write for you — their own line is "your work, written with AI, not by AI." It just gets you to the end of the sentence you were already going to write, faster.

It works almost everywhere you type on a Mac: Apple Mail, Slack, Notion, Obsidian, Safari, Chrome, Notes, Messages, Word. The real catch is hardware — it needs an Apple Silicon Mac (M1, M2 or newer), because your own computer is doing the thinking. Their claim is up to 50% less typing.

Why a founder might care

If your week is full of short writing — replies, follow-ups, notes, briefs — the time doesn't disappear into any one message. It leaks out a few seconds at a time, hundreds of times a day. Cotypist goes straight at that gap: the mechanical stretch between knowing what you mean and getting it typed.

And because nothing leaves your Mac, it's one of the few AI tools you can point at genuinely confidential work without a second thought. There's no new app to live inside and no workflow to learn — it just makes the typing you already do shorter. It's free while in beta, with a 25% early-adopter discount locked in for whenever paid plans arrive.

Words worth knowing

Autocomplete — Software guessing the rest of what you're typing and offering it to you. Your phone does a crude version; this is the same idea, far smarter, and everywhere on your Mac.

On-device / local AI — The AI runs on your own computer instead of a company's servers. More demanding on your hardware, but private and able to work offline.

Apple Silicon — Apple's own chips (M1, M2 and newer) that replaced Intel in Macs from 2020 onward. Fast enough to run small AI models locally, which is exactly why Cotypist requires one.

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A question worth sitting with: how much of your writing is choosing the words, and how much is just the keystrokes to get them down? The first part is yours. The second is the part a tool like this quietly hands back.