ProtocolOS

An offline-first fitness PWA — training plans, progressive-overload coaching, CrossFit WODs, and nutrition tracking — built entirely in vanilla JavaScript with zero backend.

Live app: flowopsai.co.il/fitness_app

ProtocolOS is a complete personal training system that runs 100% in the browser. All data lives in localStorage, the service worker keeps it working with no connection, and it installs to the home screen like a native app. The UI is in Hebrew (full RTL support).

Features

Training

• Push / Pull / Legs / Arms split with weekly scheduling — supports 1–7 training days per week, including A/B and A/B/C split variants
• Home-workout mode with three equipment tiers: bodyweight only, resistance bands, or dumbbells — the app resolves the active plan automatically from the user's equipment
• Exercise database of 100+ exercises, each with Hebrew and English names, set/rep schemes, rest times, difficulty level, target muscles, technique description, form tips, and exercise alternatives
• Integrated rest timer with Web Audio API beeps and device vibration
• Plate calculator and 1RM calculator (estimated one-rep max, updated when a PR is saved)

Progressive-Overload Coach

A rule-based coaching engine analyzes each exercise's logged history and tells the user what to do next:

• Detects stagnation (4+ identical sessions) and suggests changing the exercise or intensity
• Detects when the rep-range ceiling is hit repeatedly and prompts a +2.5 kg increase
• Detects when weight is too heavy (reps below range) and suggests a deload
• Per-exercise SVG sparklines visualize the last 6 sessions at a glance

CrossFit

• 20 curated WODs — benchmark workouts (Fran, Annie) and Hero WODs (Murph) plus home-friendly ones — in AMRAP, EMOM, and For Time formats with time caps
• Deterministic WOD-of-the-day rotation and score logging per workout

Nutrition

• BMR / TDEE calculation (Mifflin-St Jeor) with goal-based calorie targets — lean bulk, bulk, cut, maintain — and automatic protein/fat/carb macro split
• Daily food diary with product search powered by the Open Food Facts API
• Water intake tracker
• AI nutrition advisor: works fully offline with a built-in rule-based Q&A engine, and optionally upgrades to the Claude API (user supplies their own key, stored locally only)

Progress & Gamification

• Body-weight log with progress graph, body measurements, PR tracking, RPE and recovery logging, habit tracking
• XP system, streak-based achievement badges, and rotating weekly "boss challenges" (e.g. 100 push-ups this week, 5,000 kg total volume)
• Full JSON export/import for backup and device migration

App Experience

• Installable PWA with app shortcuts that deep-link straight into PUSH/PULL/LEGS/ARMS day
• Three themes: dark, light, and AMOLED
• Portrait-oriented, standalone display, RTL Hebrew UI

Tech Stack

Layer	Choice
Language	Vanilla JavaScript (ES modules) — no framework
Offline	Service Worker + Cache Storage
Persistence	localStorage only — no backend, no accounts, no tracking
External APIs	Open Food Facts (food search), Claude API (optional, user-keyed)
Build	Vite + Terser minification
Testing	Vitest — pure logic extracted to src/pure.js for unit testing
CI/CD	GitHub Actions: test, then build and deploy to GitHub Pages on every push to main
Hosting	GitHub Pages behind a custom domain

Architecture Notes

• Offline strategy (sw.js): network-first for the app shell (HTML/JS/CSS) so users always get fresh code when online, with cache fallback when offline; cache-first for static assets (icons, fonts). Old caches are purged on activation and open clients are notified via postMessage when a new version is live.
• No backend by design. Every feature — workout logs, nutrition history, achievements — is computed client-side and persisted in namespaced localStorage keys. The result: zero hosting cost beyond static files, instant loads, and complete data privacy.
• Data migration and backup are built in: state can be exported as a dated JSON file and re-imported on another device.
• Testable core: nutrition math, rep-range parsing, and sparkline generation live as pure functions in src/pure.js, covered by Vitest and gated in CI before deploy.

Try It

1. Open flowopsai.co.il/fitness_app on your phone or desktop.
2. On mobile, choose "Add to Home Screen" to install it as a PWA.
3. Turn on airplane mode — it keeps working.

Development

npm ci
npm run dev      # Vite dev server on port 3000
npm test         # Vitest unit tests
npm run build    # production build to dist/

License

ISC