A FOCUS PRACTICE FOR YOUR MAC

One thing at a time.
A witness that’s kind.

You sit down. The screen asks one question. You answer. It waits inside the notch, and once an hour Claude — through your own Claude Code — quietly checks whether you stayed with it. It never blocks anything.

Download for Mac · free · macOS 14+
Universal DMG, signed & notarized. Needs Claude Code for the witness; works without it in switches-only mode.
Nothing hangs from the notch. Move the cursor into it and the panel drops out: what you’re on, the hour, and the day so far.

Declare. Hold. Witness.
Then ask again.

Every intent-aware focus app on the Mac watches you in real time and punishes the wandering mind — closing tabs, throwing tomatoes, fining you. That’s how you learn to hate the nagger, not how you learn to return. One Thing asks once an hour, speaks tentatively, shows you what it saw, takes correction, and never blocks anything.

The Gate

When you sit down, every display goes to one question: what’s the one thing? You can’t get past it without an answer — or an honest “off duty”. After a break it asks “still on it?” and one keystroke gets you back.

The Notch

Nothing sits on your menu bar and nothing hangs from the notch. Move the cursor into the notch, press ⌃⌥O, or double-tap ⌥, and a panel drops out of it with your one thing, the hour, the switches, the day so far, and Done. It closes when you leave.

The Witness

Every three minutes a small frame; once an hour the twenty of them go to Claude through your own Claude Code with one question: was this person doing what they said? You see exactly what it saw.

The Practice

Focus score, threads per hour, longest unbroken stretch, switches per day. Better, holding, or slipping — against your own last three weeks. Never a leaderboard, never a streak to break.

Silence is the reward.
Drift gets one kind sentence, from the notch.

Finish the pricing page

Aligned

The dot turns sage for the hour. Nothing appears. Good work is never interrupted.

Finish the pricing page

Drifting

“Last hour drifted toward Slack and Gmail. The pricing page is still the one thing.” The notch opens with the sentence for twenty seconds, then closes.

Finish the pricing page

Witness paused

Gray while you’re on a call, in a private app, idle, or Claude is offline. The notch still holds the thing.

What stays private.
Shown in these words at first launch.

  1. Screenshots stay on this Mac. Frames are kept for 24 hours so you can see what the witness saw, then deleted.
  2. Once an hour, twenty small frames and their captions, plus your declaration, go through your own claude command line to your own Claude account (or your employer’s, if they pay for your Claude Code). One Thing has no servers, accounts, or telemetry.
  3. Frames are skipped while a private app is in front, and private apps’ windows are blanked out of every frame. Nothing is captured while your camera is on, while the screen is locked, or while you’re idle.
  4. You can see exactly what the witness saw, and correct it.
  5. No keystrokes, no audio, no browsing history, no window titles kept beyond the frames’ 24 hours.
  6. The menu-bar dot is filled only while capture is possible. Off duty is always one click.

The honest
FAQ.

Does it block apps or websites?

No. Never. Not sites, not apps, not after a bad hour. Blocking teaches nothing; the habit is unchanged the moment it’s off. One Thing reports and reminds.

Do I need Claude Code?

For the witness, yes — One Thing runs claude -p on your own machine with your own subscription, so there are no servers and no API keys. Without it, the Gate and the notch panel still work and hours show as “unwitnessed” with a simple app-switch count.

What does it cost to run?

The app is free, always. The witness uses a small slice of your Claude quota: one short call per judged hour, about six thousand tokens, nothing when you’re idle, off duty, or in quiet hours.

macOS asked again about Screen Recording. Why?

macOS 15 and later re-ask roughly monthly (and after OS updates) for any app that captures the screen without the system picker. That’s the system checking in, not One Thing asking for more. Screen Recording is the only permission it ever needs.

Can I get out of the Gate in an emergency?

Always. “Off duty” is one click on the Gate itself, “someone else is using this Mac” pauses until the next unlock, Spotlight and the lock screen still work, ⌘⌥⇧Esc still works, and holding Esc for three seconds quits the app (logged in your own journal). You can also switch the Gate to “ask, don’t insist” in Settings.

Is anything shared with anyone?

No. Frames stay on your Mac. Verdicts stay on your Mac. The only thing that leaves is the hourly call to Claude through your own account. There is nothing to export to a team, by design.

Free.

No tiers, no keys, no payment links. Auto-updates in place.

Download One Thing · 1.2.0 · universal
macOS 14 Sonoma or later · Apple silicon and Intel · signed & notarized