Native macOS App — Free & Open Source

Know when your
brain needs a break.

Reflex monitors your cognitive load in real time — watching typing rhythm, mouse behavior, and context switching. It learns your patterns, then tells you exactly when to step away. No wearable. No cloud. 100% private.

100% Private No Wearable Free Forever Open Source
Reflex app icon
72 Elevated
0–100 Real-time Load Score
6 Biometric Signals Tracked
0 Bytes Sent to Any Server
Free Always, No Subscriptions

See Reflex in Action

Watch how Reflex silently monitors your work session, detects overload, and triggers a smart break — all without interrupting your flow.

Built for the way you actually work

Every signal Reflex monitors translates directly to mental fatigue. Six data streams, one clear number — and smart breaks when you need them.

Real-Time Cognitive Load Score

A live 0–100 score updated every 5 seconds. Six weighted signals — typing variance, error rate, context switches, mouse jitter, pause frequency, and scroll chaos — are fused into a single number via exponential moving average smoothing.

● Flow (0–25) ● Moderate (26–50) ● Elevated (51–75) ● Overloaded (76–100)

Personal Baseline Learning

Reflex spends 15 minutes learning your normal typing and mouse patterns. Scores are always relative to your baseline — not a generic population average.

Always-On Menu Bar

Lives quietly in your menu bar. One click opens a popover with your live load ring, real-time metric tiles with trend arrows, quick break actions, and a link to the full dashboard.

Smart 3-Stage Break System

When overload persists, Reflex triggers a cinematic break sequence: a cursor-following countdown orb → a slide-in notification with snooze/skip options → a fullscreen overlay with a guided 4-4-4 breathing exercise. It knows when to step in — and when to step back.

Deep Analytics Dashboard

The full dashboard shows session history with inline charts, a weekly load trend, a 24-hour focus heatmap, and personalized insights. Export all your data to CSV any time you like.

6 Biometric Input Signals

Typing rhythm variance · Backspace error rate · Inter-key pause frequency · Mouse jitter & velocity variance · Scroll chaos (direction reversals) · App context-switch rate. No key content is ever captured — only timing and movement patterns.

Fully Customizable

Adjust sensitivity from relaxed to aggressive. Set break intervals (10–30 min) and durations (2–10 min). Toggle the breathing exercise, launch at login, and dock visibility. Reflex adapts to your workflow.

From install to insight in minutes

No account. No config. No wearable. Just install, grant one permission, and let Reflex work.

01

Download & Install

Download the DMG. Drag to Applications. Launch Reflex — it lives in your menu bar, never your Dock unless you want it to.

02

Grant One Permission

Reflex only needs macOS Accessibility access to observe input event timing globally. One tap in System Settings is all it takes.

03

Baseline Calibration

Just work normally. In about 15 minutes Reflex has learned your personal typing and mouse rhythms, and starts scoring relative to your baseline — not anyone else's.

04

Smart Breaks, On Cue

When your load climbs and stays elevated, Reflex gently nudges you with a cursor-following countdown, a snooze-able notification, or a full guided breathing break.

Six signals. One clear number.

Reflex combines behavioral signals that correlate with cognitive fatigue, weighted by their predictive significance.

Typing Rhythm Variance 25%

Erratic inter-keystroke timing is the earliest indicator of mental strain.

Error Rate (Backspaces) 20%

Correction rate spikes when working memory is overloaded.

App Context Switches 20%

Rapid app switching fragments attention and deepens fatigue.

Mouse Jitter 15%

High velocity variance reflects physical tension and reduced motor control.

Pause Frequency 10%

Long thinking pauses between keystrokes indicate heavy cognitive processing.

Scroll Chaos 10%

Rapid scroll direction reversals suggest confusion or information overload.

100% Private.
Zero Compromises.

Reflex was designed from the ground up with a simple law: your data never leaves your Mac. No account, no cloud sync, no telemetry — ever.

No keystrokes recorded Only the timing between keystrokes — never the keys themselves.
No screenshots or screen access Only input event patterns — cursor position, timing, scroll direction.
Zero network calls No internet connection used. Reflex works completely offline.
No analytics or telemetry Your usage patterns are yours alone. Nothing is reported anywhere.
All data stored locally Sessions and baseline stored in ~/Library/Application Support/Reflex/. You own it — delete it any time.
Fully open source Don't just take our word for it — read every line of code on GitHub.

macOS requires Accessibility permission to monitor input events globally. This is the same permission used by apps like Raycast and Bartender. You can revoke it any time in System Settings.

Get up and running in 2 minutes

Reflex is a free, unsigned app — macOS will flag it the first time. Here's exactly what to do.

1

Download the DMG

Click the Download button on this page. The file is Reflex-1.2.1.dmg. It will download to your Downloads folder.

2

Open the DMG and drag to Applications

Double-click to open the DMG. Drag Reflex.app to the Applications shortcut in the same window.

3

Right-click → Open (first launch only)

Find Reflex in Applications. Right-click it → Open — do NOT just double-click. macOS shows a warning about an unidentified developer.

Why does this happen? Reflex isn't notarized through Apple's $99/year Developer Program. It's fully open source — inspect every line on GitHub.
4

Enable in Privacy & Security (if blocked)

If macOS still refuses to open it, go to:

Open System Settings
Privacy & Security
Click "Open Anyway" next to Reflex
You only need to do this once. After that, Reflex opens normally like any other app.
5

Grant Accessibility Permission

Reflex will prompt you to grant Accessibility access. This is the only permission it needs. Click Open System Settings → toggle Reflex on in Privacy & Security → Accessibility.

No keystroke content is captured — only the timing and rhythm between keystrokes. Your text stays yours.
6

You're all set

Reflex appears in your menu bar as a small brain icon showing your current load score. It starts learning your baseline immediately. In about 15 minutes it'll be fully calibrated.

System Requirements

  • macOS 15.0 Sequoia or later
  • Apple Silicon or Intel Mac
  • ~10 MB disk space
  • Accessibility permission (only)
  • No internet connection required
Latest Release v1.2.1 View all releases →
Open source Every line of code is public. Audit it yourself.
View on GitHub
Reflex

Ready to work smarter?

Join the humans who've stopped guessing how tired their brain is.

v1.2.1 · macOS 15 Sequoia+ · Free, forever

First time opening? See the installation guide above for macOS security instructions.