
Onyx: Fitness & AI Coach
Recovery, Macros & AI Coach
About
This app acts as a personalized AI fitness coach, analyzing your wearable data to provide tailored advice on training, nutrition, and rest. It offers detailed recovery scores, sleep analysis, and illness early warnings based on your unique metrics.
What's New in Onyx
3.0
August 18, 2026
Feature Pack 3.0 — the biggest release since launch. EATING OUT, SOLVED Point your camera at the menu. Onyx reads it and ranks every dish against the calories and protein you have left — best pick first, with the reason it wins. IT NOTICES BEFORE YOU DO Resting heart rate up, HRV down, breathing off your baseline — the three signals that drift a day or two ahead of the sore throat. Onyx now watches all of them, and the reading costs nothing. ASK FOR ARMS. GET AN ARM DAY. Sessions are built the way a coach would build them — the lift that deserves you fresh goes first, isolation finishes. Chest, Back, Shoulders, Arms and Glutes are all focuses now. YOUR WATCH WORKS ALONE The Apple Watch app now runs a full session on your wrist with no phone in the room. Your workout syncs back when you reconnect. RECOVERY READS YOUR WHOLE NIGHT Sleep now scores breathing quality, not just hours. Blood oxygen, heart-rate recovery and time on your feet feed your daily read for the first time. AND EVERYTHING ELSE • A weight goal that corrects your calories as you drift • Form notes on all 213 movements • How regular your sleep actually is — and what weekends cost you • Are your training days too similar? Onyx will say so • Pacing analysis on every steady cardio session • VO₂ max ranked against your age group, not shown as a bare number • Food you can look into — additives, processing, real facts • Every screen leads with the answer, then one thing to do • Coach rebuilt: copy an answer, stop it mid-thought, follow up in a tap • Personal bests, and sending a workout to a friend • Dozens of fixes to weights, rest and streak maths
MoreSubscription plans
Onyx Pro Yearly
Unlimited AI Coach, smart food log, every Pro feature.
In-App Purchases
$79.99
Onyx Pro Lifetime
Pay once, get forever — every Pro feature we add later.
FAQ
What data does Onyx use to provide coaching?
Onyx reads data from your Apple Watch and other connected wearables via Apple Health, including workout history, sleep patterns, heart rate variability (HRV), resting heart rate, and wrist temperature to offer personalized insights.
How does Onyx score recovery and sleep?
Onyx calculates a recovery score from 0-100 based on HRV, resting heart rate, sleep, and wrist temperature, comparing it to your personal baseline. Sleep is also scored from 0-100, broken down by duration, deep/REM stages, efficiency, and consistency.
Can Onyx help with illness detection?
Yes, Onyx can provide early illness warnings by detecting combined signals like drops in HRV, climbing RHR, and drifting wrist temperature, alerting you before symptoms become apparent.
What are the features of Onyx Pro?
Onyx Pro offers unlimited coaching messages, workout scoring, a smart AI food log, and detailed illness analysis, in addition to the features available in the free version.
What is the pricing for Onyx Pro?
Onyx Pro is available for $4.99 per month, $39.99 per year with a 7-day free trial, or a lifetime purchase of $79.99.
Does Onyx have ads?
No, Onyx does not have advertisements. The app is free to use with core features, with an optional paid upgrade for advanced functionalities.
What devices and platforms does Onyx support?
Onyx requires an iPhone running iOS 18 or later and connects with Apple Health. It is compatible with Apple Watch and most third-party wearables like Whoop, Oura, Garmin, and Fitbit.
How often is Onyx updated?
The latest version of Onyx is 2.3, and it was last updated on May 27, 2026. This indicates a relatively active development cycle.







