Satori

A free, open-source study app for the digital SAT that runs entirely on your own computer: no accounts, no payments, no cloud.

Every question comes with a step-by-step explanation and a note on why each wrong choice is wrong. All questions are original: written for this project or produced by math template generators. None are copied from the College Board or any prep site.

Scores shown in Satori are estimates from your practice answers, not official SAT scores. See docs/SCORING.md.

Home	Practice
Learn path	Analytics

Features

• Study: home dashboard with a test-date countdown and predicted score, a day-by-day study planner that rebuilds itself when you miss a day, a date-unlocked learn path with a calendar, and analytics by section, domain, skill and difficulty.
• Practice: filterable question bank, a practice player (multiple choice and grid-in, KaTeX math, answer eliminator, timer, Desmos calculator, reference sheet), Saved & Mistakes with "Redo my mistakes", Question Rush and Challenge Questions.
• Tests: full-length, section and single-module practice tests in the digital SAT format with adaptive module 2, a Bluebook-style interface and detailed score reports.
• Learn: a lesson for every skill, custom lessons built around your results, and 121 vocab words with spaced-repetition flashcards.
• Profiles: several local profiles (for example, siblings sharing a laptop) with a weekly leaderboard, plus backup and restore of the whole database.
• Optional AI (Claude or a free local Ollama model): a tutor that gives hints, and a question generator with an independent solve-check and a review queue. Everything else works without it.
• Content: 132 hand-written Reading & Writing questions, 64 hand-written Math questions, and 26 math generators (580 generated questions by default), each with its source and license. You can also import your own questions from JSON or CSV.

Light and dark mode, phone-width layouts, keyboard navigation and AA colour contrast throughout.

Tech stack

Next.js 16 (App Router) · TypeScript · Tailwind CSS 4 · SQLite through Node's built-in node:sqlite · KaTeX · Vitest · Playwright. The AI features are optional and use the Anthropic SDK or Ollama.

Prerequisites

• Node.js 22.13 or later (check with node -v). No native build tools are needed on Windows, macOS or Linux.
• Git.
• Optional: Docker, if you'd rather run it in a container.

Install and run

git clone https://github.com/asoofy/satori.git
cd satori
npm install
npm run dev

Open http://localhost:3000. On first launch Satori creates data/satori.db, applies the migrations and loads the bundled questions automatically.

For a production build, run npm run build and then npm start. With Docker, run docker compose up -d (data is kept in the satori-data volume).

Satori has no login, so by default it only accepts connections from your own computer. To use it from another device on a network you trust, see SECURITY.md.

Command	What it does
npm run dev	Start in development mode
npm run build then npm start	Production build and server
npm run seed	Reload the bundled content. Your progress is kept
npm test / npm run test:e2e	Unit tests (Vitest) / Playwright smoke tests on a throwaway database
npm run lint / npm run typecheck	ESLint / TypeScript

Configuration

No configuration is required. To change anything, copy .env.example to .env.local and uncomment what you need; each variable is explained there.

Variable	Purpose
SATORI_DB_PATH	Where the SQLite file lives (default data/satori.db)
ANTHROPIC_API_KEY	Turns on the AI features with Claude (SATORI_AI_MODEL overrides the model)
OLLAMA_URL, OLLAMA_MODEL	Turns on the AI features with a free local model instead
NEXT_PUBLIC_DESMOS_API_KEY	Your own Desmos key (the public demo key is used otherwise)
OPENSAT_URL	Address of the optional OpenSAT importer

With no AI configured, the tutor is hidden and the generator shows setup instructions. The Desmos calculator needs an internet connection; everything else works offline.

Project structure

app/                  pages (App Router), server actions, route handlers
components/           UI: practice player, test runner, charts, calendar, Markdown + KaTeX
lib/                  database, grading, scoring, planner, test engine, AI, import/export
db/migrations/        plain SQL migrations, applied automatically on startup
content/              taxonomy, hand-written questions, math generators, lessons, vocab
scripts/              seed, e2e reset, screenshot capture
tests/                unit (Vitest) and e2e (Playwright) tests
docs/                 scoring model, content guide, screenshots

Contributing

Contributions are welcome, especially original questions and new math generators. See CONTRIBUTING.md. To report a security problem, see SECURITY.md.

License

• Code: MIT.
• Original content (questions, explanations, generator text, lessons, vocabulary): CC BY 4.0.
• Imported questions keep their own source and license.

Satori is not affiliated with or endorsed by the College Board. SAT is a trademark registered by the College Board.