An open-source study system for university students. It plans your week with AI, guides each session in focus blocks and measures what you know unaided — because research shows that hours studied and performance during practice are poor signals of learning (Roediger & Karpicke, 2006; Rohrer & Taylor, 2007; Bastani et al.).
- AI weekly plan — built from your subjects, exam dates and free hours, around retrieval, spacing and interleaving; a fixed scientific check flags what to adjust. Gemini, Claude or any OpenAI-compatible API.
- Focus mode — full-screen 40+10 blocks, screen kept awake, a timer that survives the phone killing the app.
- Block log — attempts, confidence and help used are recorded before checking; the score comes after.
- Unaided mastery — only from closed-book tests on paper; assisted practice is shown separately, with a reliance-on-help warning.
- Calibration — subjects where your confidence fools you rise to the top.
- Degree record — curriculum import from a photo, ECTS-weighted average, the grade you need to keep it, weighted assessments with minimum grades, resits and special exam periods, prerequisites, semester report.
- In-app setup — keys, database tables and publishing to Cloudflare from one screen, with a status dot per service.
- Sync and offline — phone ↔ computer in real time; installable PWA; JSON backup.
- English and Portuguese — interface, server messages and AI plans in the language you choose (Account → Language).
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npx estudar # opens http://localhost:8787 (needs Node.js 20+)In the app: Account → Server & keys → paste your Supabase details and AI key → Test → Save → Connect Cloudflare account → Publish. Keys are stored in ~/.estudar. Full guide in docs/en/guide/installation.md.
With nothing configured, the app already works in local mode (data stays in the browser).
| Part | Technology |
|---|---|
| App | PWA with no build step — HTML, CSS, ES modules (public/) |
| Server | One Cloudflare Worker serves the app and the API; npm start runs the same API locally |
| Data | Supabase: sign-in with an emailed code, one JSON document per user with RLS, Realtime |
| AI | Configurable; the key only ever lives on the server |
| Rules | learning.js and curriculum.js, pure functions with mutation-verified tests |
| Languages | i18n.js + one dictionary per language; a test fails if any string is untranslated |
More in Architecture and Data model.
git clone https://github.com/RyanTech00/estudar.git
cd estudar
npm install
npm start # app + API + setup screen
npm test # learning, degree-record and translation rules
npm run check # build the Worker without publishing
cd docs
npm install
npm run dev # documentation site
npm run screenshots # regenerate screenshots (both languages) with a fictional student
npm run build # build and check links and anchorsIssues and pull requests are welcome — see the contributing guide. Before changing a learning rule, read the principles: they are invariants, and each one has tests.
Estudar is free and will stay free. If it saved you time — or a module — a coffee helps keep it going.
MIT © 2026 Ryan Barbosa
Co-Authored-By: Claude Opus 5.5