OpenFit

Open-source fitness platform that connects wearables via Health Connect + BLE (Android only), tracks workouts (strength training, runs, jiu-jitsu), and displays health analytics on a web dashboard.

Tech Stack

Layer	Technology
API	Fastify v5, TypeScript, Prisma, PostgreSQL
Web	Next.js 15 (App Router), Tailwind CSS, Recharts
Mobile	React Native, Expo (bare workflow), Expo Router — Android only
Shared	Turborepo, Zod schemas, shared types + business logic

Monorepo Structure

openfit/
├── apps/
│   ├── api/             # Fastify backend (port 3001)
│   ├── web/             # Next.js dashboard (port 3000)
│   └── mobile/          # React Native + Expo
├── packages/
│   ├── types/           # Zod schemas & shared TypeScript types
│   ├── db/              # Prisma client, schema & seed script
│   ├── fitness-core/    # Pure business logic (HR zones, pace, calories)
│   └── ui/              # Shared React components
├── ARCHITECTURE.md
└── CLAUDE.md

Prerequisites

• Node.js >= 20 (nvm use 20)
• Docker (for PostgreSQL)
• npm >= 10

Getting Started

1. Clone and install

git clone https://github.com/adrienfloor/OPENFIT.git
cd OPENFIT
npm install

2. Start PostgreSQL

docker compose up -d

This starts a PostgreSQL 16 instance on port 5432 with credentials openfit:openfit.

3. Configure environment

cp apps/api/.env.example apps/api/.env
cp apps/web/.env.example apps/web/.env
cp apps/mobile/.env.example apps/mobile/.env

Edit apps/api/.env and set real values for:

• JWT_ACCESS_SECRET — any random 32+ char string
• JWT_REFRESH_SECRET — a different random 32+ char string

4. Set up the database

npm run db:generate   # Generate Prisma client
npm run db:migrate    # Run migrations (creates tables)
npm run db:seed       # Seed with test data

The seed creates:

• 2 test users (alice@openfit.dev / bob@openfit.dev, password: Password123)
• 10 exercises, 3 programs (Push/Pull/Legs, Upper/Lower, Full Body)
• 14 days of synthetic health data per user

5. Start development

npm run dev         # All apps in parallel
npm run dev:api     # API only
npm run dev:web     # Web only
npm run dev:mobile  # Mobile only

Available Scripts

Command	Description
npm run dev	Start all apps in parallel
npm run dev:api	Start API server only
npm run dev:web	Start web dashboard only
npm run dev:mobile	Start Expo dev server only
npm run build	Build all packages and apps
npm run test	Run all test suites
npm run lint	Lint all packages
npm run typecheck	TypeScript check all packages
npm run db:generate	Generate Prisma client
npm run db:migrate	Run Prisma migrations
npm run db:seed	Seed database with test data

Authentication

Custom JWT implementation with access + refresh token rotation. No third-party auth provider.

• Access token: 15-minute lifespan, signed with JWT_ACCESS_SECRET
• Refresh token: 30-day lifespan, SHA-256 hashed in DB, rotated on every use
• Mobile: access token in memory (Zustand), refresh token in expo-secure-store (native keychain)
• Web: access token in memory, refresh token in HttpOnly cookie

API Endpoints

POST /auth/register   # Create account, return tokens
POST /auth/login      # Verify credentials, return tokens
POST /auth/refresh    # Rotate refresh token, return new pair
POST /auth/logout     # Invalidate refresh token
GET  /auth/me         # Return current user profile

Test Users

Email	Password	Role
alice@openfit.dev	Password123	user
bob@openfit.dev	Password123	admin

Testing

# All tests
npm run test

# Specific packages
cd packages/fitness-core && npx vitest run   # 11 tests (HR, pace, calories, ACWR)
cd apps/api && npx vitest run                # 11 tests (auth flows, multi-tenancy)

Architecture

See ARCHITECTURE.md for:

• System diagram
• Auth flow (register, login, refresh rotation, logout)
• Data flow (wearable -> Health Connect / BLE -> mobile -> API -> DB -> clients)
• Multi-tenancy model
• Key technical decisions with rationale
• Offline-first strategy

Multi-Tenancy

Every user-owned model has a userId foreign key. Every database query is scoped to the authenticated user's ID extracted from the JWT. No global queries on user data.

Roadmap

Phase 0 (current) — Foundation

• Monorepo with Turborepo
• Shared types (Zod schemas)
• Fitness-core business logic with tests
• Prisma schema (13 models)
• JWT auth with refresh token rotation
• Web auth pages + dashboard layout
• Mobile auth screens + tab navigation

Phase 1 — Core Features

• Health Connect + BLE integration (implemented, needs UI wiring)
• Workout CRUD (programs, sessions, logs)
• Run tracking (GPS, pace, elevation)
• Health dashboard with charts (Recharts)
• Mobile offline sync (Drizzle + SQLite)

License

MIT