SimpleBrain

A note app that doesn't make you configure it. Notes with [[links]], a live graph of how they connect, tasks with due dates, a calendar, and an inbox where you type a thought and file it with one click. No plugins, no query language, no account. Your notes are plain Markdown files in a folder you own.

Install

Linux (x86-64): download SimpleBrain-x86_64.AppImage from the latest release, then:

chmod +x SimpleBrain-x86_64.AppImage
./SimpleBrain-x86_64.AppImage

Windows and macOS builds aren't available yet. To build from source, see below.

Using it

• Capture: type anything in the bar at the top and press Enter. It lands in the Inbox, where one click files it as a Task, Event or Note.
• Notes: link notes by writing [[Note Name]]. Clicking a link opens (or creates) that note. The graph shows every link; click a dot to open it.
• Tasks: any line like t call the bank due:10-01-2026 in any note shows up under Overdue / Today / Upcoming / No date. Ticking it makes it - [x] …; old - [ ] … lines are converted to t … automatically.
• Shorthand (any note, on save): a line starting i moves to the Inbox, c 10-05-2026 2pm dentist moves to the Calendar (time optional). Lowercase only, so I think… is left alone.
• Calendar: add local events, or show a read-only calendar feed by adding ICS_URL=https://… to the .config file in your notes folder.
• Dataview: every note in a table, filterable by #tag or title. The matching notes light up orange in the graph.
• Answers: under a numbered question, write answer:: your answer. Each [[Keyword]] you link gets a Keyword - Answers note listing every note that links to it, then all their answers. It rebuilds on save; don't edit it.

Your notes live in Documents/SimpleBrain (File → Open vault folder). Deleted notes go to .trash inside it, never straight to oblivion.

Settings (in .config in your notes folder):

Set the environment variable SIMPLEBRAIN_VAULT to use a different notes folder, e.g. a USB drive.

Build from source

Python 3.10+:

pip install -r requirements.txt
python simplebrain_app.py

Tests: python simplebrain_core.py and QT_QPA_PLATFORM=offscreen python tests/test_app.py.

Installers: pip install -r requirements-build.txt && pyinstaller packaging/simplebrain.spec, then packaging/linux/build-appimage.sh (Linux AppImage). Release builds use packaging/linux/build-in-docker.sh, which compiles inside Ubuntu 22.04 so the AppImage runs on older distributions too. On Windows, with Inno Setup:

python -c "from PIL import Image; Image.open('packaging/icon.png').save('build/icon.ico', sizes=[(16,16),(32,32),(48,48),(64,64),(128,128),(256,256)])"
iscc /DAppVersion=<VERSION from simplebrain_core.py> packaging\windows\simplebrain.iss

Project layout

• simplebrain_core.py: notes, links, tasks, inbox, calendar, answers. No UI.
• simplebrain_app.py: the desktop app (Qt).
• packaging/: icon, PyInstaller spec, Linux AppImage/install scripts, Windows installer.

License

MIT, see LICENSE.