Documentation

A memory companion for your Mac. Write atoms in your notes, and reviews drop from the notch while you work.

Atomus is a Mac app for remembering what you write down. You write notes in its editor, mark what you want to remember as atoms, and a few minutes or a few weeks later that atom drops from your notch while you're already working. Atomus keeps an icon in your menu bar so reviews can find you even when the editor window is closed.

Your notes are plain Markdown files on your Mac. We never see them.

What is an atom?

The smallest unit of memory in Atomus. Start here if the word is new to you.

Creating atoms

Every syntax Atomus reads: QA, multi-line, multiple choice, lists, cloze, and deadlines. One page, with examples.

Memory that sticks

FSRS schedules each atom to come back right before you were about to forget it.

Reviews in the notch

Atoms drop from your notch while you work. One key, no context switch.

Local-first vault

Your notes live as plain Markdown on your Mac. No sign-up, no cloud, yours to keep.

Three acts, one loop

Writing is cheap, AI is optional, review is ambient. Each piece is small. Together they form a loop that quietly raises the floor of what you remember.

Start here

Install Atomus, pick a folder for your vault, and write your first atom. The whole flow is in Getting started. Questions about activation, updates, or renewal are answered in License and updates.

Read for depth

If you want the philosophy first, Why Atomus covers the 140-year-old experiment behind the app, why your notes live on your Mac, and the mental model behind the design.

Who it's for

Students preparing for exams. Researchers holding years of context. Writers, engineers, and language learners. Anyone who writes things down hoping to remember them later.