Open Workout System
Open activity library, open hardware, open API.
Community driven, privacy-first, and fully customizable.
Open hardware, an open activity library, and an API your own AI agents can plug into. The app is free to use, and your data stays yours end to end.
Plan Workout Track Adapt Repeat.
Dynamic Workouts
All workouts and schedules effortlessly adapt to your needs and schedule. No rigid structures. You get what you need when you need it.
Connect Your AI Agent
Sees the full picture. Every exercise, meal log, and metric. Creates training plans, logs meals, monitors progress, and provides research-backed guidance. Just ask.
Simple Tracking
Quick macro logging from the command bar. Type "I just ate an apple", or type "/cal 500 p:30" and keep moving. No app-switching, no friction.
Body Composition
Physics-based projection engine. See where you'll be in 12 weeks based on your actual training, protein intake, and metabolic rate.
Open Activity Library
Every exercise is open data under CC BY-SA 4.0, with provenance and a public API. Use it in your own tools, or improve it and share back.
Open Hardware
Open hardware designs and firmware for our digital weight device, CERN-OHL-S licensed. Build it, modify it, connect it.
Open Hardware
A Powerful Workout System
Replace freeweights, cable machines, and rowing machines all with one single 12 lb device. The Digital Weight. The Digital Weight also supports paddle boarding and cycling exercises when paired with optional accessories.
We also expose and make our hardware API open-source for any fitness hardware developer to support. Want your favorite equipment supported? or contribute a device descriptor.
Your Choice
Connect Your AI Agent.
Use built-in assistant tools and features with your own agent working locally or remotely. Either way — creating exercises, logging nutrition, building programs, tracking progress — it all runs through the same tool interface.
Built-in Assistant
Bring your own AI key (OpenRouter, Anthropic, OpenAI, xAI) and chat on your own account with the model you choose. Understands your entire fitness profile, takes action on your behalf, and learns your preferences over time.
Bring Your Own Agent
Add the OWS connector to Claude or ChatGPT — sign in, approve once, and the AI you already pay for can log workouts, track nutrition, and manage your programs. Works on claude.ai (every plan, mobile included). Power users: connect Claude Code, Cursor, or agents like Hermes over MCP with an API token — or use the REST API from any language.
MCP /api/mcp · OAuth connector or API token
REST /api/remote/tools · /execute · /context
“Hermes, check my training log every Sunday night and adjust next week's program.”
It understands your entire fitness journey — training history, nutrition, goals, injuries. It takes action, plans before it acts, verifies its work, and learns your preferences over time.
// 58 tools, one interface
Every action the assistant takes — creating exercises, logging meals, building programs — uses the same tool system available to external agents via HTTP REST or MCP. Same capabilities, whether it's the built-in trainer or your own agent.
Community-Powered
The Activity Library
Think Wikipedia for exercises. A growing, crowdsourced database of activities, each with detailed instructions and more. Extensible parameters. muscle activation maps, auto-generated thumbnails, step-by-step images, and video animations. Contributed by users, enriched by AI, reviewed by humans.
- •Thousands of exercises with full metadata and visual guides
- •AI driven management, procurement, and mediation of user contributions
- •Open API — any app or device can read from and contribute to the library. Community contributions means open library as it should be.
- •Auto-generated thumbnails, and animation videos for every exercise which can be overridden by user contributions to ensure accuracy.
- •External links for instructional references and research publications in relation to the activity.
Developer-Friendly
Built for Integration
Open APIs for everything. Connect your own hardware, build your own UI, pipe data into your own systems. The platform is the foundation. What you build on top is up to you.
Activity Library API
Read and contribute exercises and sessions. Full CRUD with metadata, images, and search.
Hardware Integration API
Wireless protocol for connecting to and controlling resistance devices, scales, wearables, and custom sensors. Real-time force, weight, and heart rate streaming.
Remote Agent API
Call the same tools via HTTP REST or MCP (Claude Desktop, Claude Code, Cursor). Query data, create exercises, log workouts, and manage programs on your behalf.