openGym

# openGym: Architecture Deep-Dive & Setup Guide Most fitness platforms hold user data hostage behind subscriptions and proprietary APIs. DuarteSantos8's **openGym** takes a self-hosted, privacy-first approach to workout and weight tracking. Released under the AGPL-3.0 license, it is a Progressive Web App (PWA) designed to give you total ownership over your workout metrics without third-party telemetry or ads. ## Architecture & Under-the-Hood Technicals openGym is built modern from the ground up, utilizing **React 19** to render its user interface. Because it operates as an installable PWA, it supports full offline operation on mobile and desktop devices. Here is how the system handles security, synchronization, and core functionality: * **Authentication & Access**: Self-hosted instances drop legacy password systems in favor of **passkey sign-in**, providing secure access across your devices. * **Data Isolation**: The app runs telemetry-free. Your data lives on your own infrastructure in folders you control, completely decoupling your metrics from external servers. * **Exercise Engine**: Out of the box, openGym embeds a searchable library of **1,324 exercises**, complete with animated demos designed to run smoothly during active workout sessions. * **Metrics & Visualization Engine**: Features interactive body-weight charts with custom goal lines, dynamically color-coding gains or losses based on progress toward your target. It also builds heatmaps, visual charts, and tracks Personal Records (PRs). * **Routine Logic**: Includes a weekly plan feature mapped per weekday, with built-in logic to reschedule missed or shifted workout sessions. The project also offers a zero-install live demo hosted on GitHub Pages. Note that while the demo runs entirely client-side using example data, backend-dependent features—like multi-device syncing, passkeys, and the admin dashboard—are activated exclusively when running a self-hosted instance. --- ## Deployment & Setup Deploying openGym requires zero complex configuration steps. The project is completely containerized for simple orchestration via Docker. ### Running via Docker Compose To spin up a self-hosted instance on your local machine or server, execute: ```bash docker compose up ``` Once containerized, you can install the web app directly to your phone or laptop home-screen and sync your workout data securely behind your passkey login. --- ## Developer Verdict If you want an offline-ready fitness tracker without nag-screens or corporate servers tracking your habits, openGym is an excellent open-source choice. The stack leverages React 19, PWA offline capabilities, and native passkey authentication to deliver a polished experience—all managed through a simple `docker compose up` command. It is clean, minimalist, and built to be easily forked.