What's inside

Your vault is the folder you picked when you set up Atomus. Open it in Finder and you'll see your notes as .md files, organized in whatever folders you like.

In the vault folder

• Your notes, as plain Markdown files, at the top level or in any subfolders you create. Includes Inbox.md, the default place for quick notes.
• Attachments/, images and files you paste or drop into notes.
• .trash/, notes you deleted in Atomus, in case you want them back.
• .atomus/, a hidden folder with Atomus's own files:
  • vault.json – the vault's ID and name
  • reviews.jsonl – your review history, one line per review
  • cards-state.jsonl – a snapshot of each atom's scheduling state, written when Git sync is on
  • settings.json – settings saved per vault, like editor options, theme, and desired retention

Your atoms aren't stored in a separate database you have to trust. They're the ==, {{cloze}}, multiple choice, list, and @YYYY-MM-DD lines in your notes.

Outside the vault

Atomus also keeps a SQLite cache for each vault in ~/Library/Application Support/Atomus/vaults/<vault-id>/. It indexes your atoms and holds their scheduling state so reviews and search stay fast. It's plain SQLite, not encrypted, and it stays on your Mac.

Peeking inside a note

A note is just Markdown. No frontmatter or hidden IDs are added.

# Memory research

What did Ebbinghaus show in 1885? == Memory decays fastest in the first day after learning

The {{forgetting curve}} describes how memory decays over time.

Edit it in any editor. Atomus re-reads the file when it changes.

Why it's built this way

If Atomus disappeared tomorrow, you could:

• Open every note in TextEdit, VS Code, or Obsidian
• Copy the folder to another Mac and keep every note and atom
• Read your review history in .atomus/reviews.jsonl with any text editor

That's the point of local-first.