openGym is a self-hosted gym and body-weight tracker that plans your weekly routines, guides every set with pre-filled weights and rest timers, and keeps your training data on a server you control instead of inside a subscription app. Over 5,600 exercises come with animated demos, searchable by body part and the equipment you own, and you can add custom ones with your own photo or video. Progression follows a rule you pick per routine (linear, Greyskull LP, double, triple, or added time), and each target explains where it came from. Supersets, warm-ups, drop sets, rest-pause, timed planks, and cardio by time and speed all log properly, and plate math shows what goes on each side of the bar. A muscle map shows where your volume went, what is still recovering, and what went untrained, beside estimated one-rep maxes, a year-long heatmap, and body weight charted against your goal. Imports from FitNotes, Strong, and Hevy carry your history over. Several people can share one server, each with a private passkey profile, and an optional admin dashboard handles invite-only signup. An optional AI coach, off by default, drafts routines and suggests changes through your own Anthropic, OpenAI, Gemini, or Ollama endpoint, and nothing applies without your approval. The interface speaks 19 languages. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. AGPL-3.0 licensed.