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For the Biohacker

The Closed Loop Your Stack Is Missing.

Your wearables measure the output. Breethly trains the input. Real-time breath biofeedback turns your nervous system from a number you read into a system you steer.

The Closed Loop

Your Stack Reads. Breethly Steers.

Real-time breath biofeedback, plotted live. Three series build as you scroll: the input layer your sensors can’t provide.

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Calm Score
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Recovery
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Breath Pace

Illustrative Breathe Metrics.

Open Loop vs. Closed Loop

Tracking Tells You. Training Changes You.

You've optimized sleep, light, cold, and macros. You have more data on your body than ever. But most of that stack is read-only: it tells you what happened after it happened.

Breath is the one lever you can pull in the moment to move your physiology on purpose. Slow it and your system down-shifts; structure it and your focus sharpens. The catch has always been knowing whether you're actually doing it. Most breathwork is open-loop guesswork.

Breethly closes the loop. The device reads your breath in real time and feeds it back to you live, so you can drive your state deliberately instead of hoping. It's the active counterpart to every passive sensor you already wear.

Why It Belongs in the Stack

The Input Layer.

Real-Time Biofeedback

Not a morning readiness score but a live signal you act on, breath by breath, to steer your nervous system in the moment.

Protocols You Can Trust

Structured breath patterns for up- and down-regulation, paced by the device so every rep is precise instead of approximate.

Pairs With Everything

Breethly trains the input; your Oura, WHOOP or Apple Watch track the output. Use them together. They answer different questions.

The Method

Drive It, Don't Just Read It.

1

Choose a Protocol

Down-regulate to recover, or up-regulate to sharpen. Each is a structured, repeatable breath pattern, not a vague 'relax.'

2

Close the Loop

The device gives live biofeedback as you breathe, so you can see in real time whether you're hitting the target state.

3

Measure the Trend

BreathOS™ logs every session into Breathe Metrics: your Calm Score, recovery speed, and consistency over time.

“Every other tool in your stack reads the dashboard. Breethly lets you take the wheel.”
Works With Your Wearable

Complement, Don't Replace.

Breethly isn't here to compete with your sensors. It does something they can't. They quantify your recovery; Breethly trains it. Read the trend on your wrist, then open BreathOS and actually move the needle.

Inhale intent. Exhale entropy. Run the closed loop.

  • Active training to pair with passive tracking
  • Live biofeedback your wrist can't provide
  • Breathe Metrics to quantify the input you control
Breethly device, the input layer of a quantified stack

Questions, answered.

It can prompt them, but it's still open-loop: it tells you to breathe and trusts that you did. Breethly adds a dedicated device that reads your breath as it happens and feeds it back in real time, so you're training against a live signal, not a timer.

Breethly is designed to live alongside them rather than absorb them: your wearables track outcomes, Breethly trains the input. See the works-with-your-wearable page for how they complement each other. Specific integrations will be detailed closer to launch.

Breethly focuses on your breath and your in-session response, distilled into consumer-friendly Breathe Metrics like your Calm Score and recovery speed. It's a wellness training tool, not a diagnostic device.

For the Biohacker

Start training today.

Join the early-access list and start training the moment BreathOS launches. The Breath Coach device follows, and founding members get it first. Founding price, locked in.

No spam. One breath at a time.