Amphetamine on Mac: how to set it up

Amphetamine is easy to run and awkward to configure, and the difficulty is not the interface. The app asks you to decide several things at once: how long a keep-awake session lasts, whether the display stays lit or is allowed to sleep, whether you start sessions by hand or let conditions start them, and what the icon reports back. Skip those decisions and the app behaves unpredictably in exactly the moments it was installed for, staying dark during a presentation or burning power overnight after a meeting ended. This walks through the decisions in the order they arrive, and marks the two places where the app cannot finish the job on its own.

Sessions are the unit, so pick a default length first

Everything in this app happens inside a session. While one runs, the Mac stays awake according to the rules you set. When it ends, normal energy settings resume with no residue. The store listing describes four ways to start one: indefinitely, for a specified amount of time, until a specified time, while a file is downloading, or while a specific app is running.

Choose the default by asking whether the task has a knowable end. Renders, backups and large uploads do not, so indefinite plus a manual stop fits them. Meetings, lectures and timed presentations do, so until a specified time fits better and removes the risk of forgetting entirely.

Indefinite sessions have one failure mode worth planning around: a laptop left awake in a bag. The app can end a session automatically when the battery gets low, which is the setting that makes indefinite safe to use on portable hardware. On a desktop Mac permanently on power, that guard matters far less, and starting indefinitely then stopping by hand is the shorter path.

A useful habit is to pick one default and use only that for the first week. Two defaults create hesitation at the moment of starting, and hesitation is what pushes people back to clicking through menus every single time.

Five behaviours you choose to allow or prevent

Keeping a Mac awake is not one switch. The listing names five behaviours that a session can allow or prevent: display sleep, screen saver activation, system sleep when the built-in display is closed, automated mouse cursor movement, and locking of the screen.

Preventing all five at once is the setting most people land on first, and it is rarely the right one. It leaves the screen lit and unlocked when you walk away. Splitting by task produces better results.

Task	Prevent	Allow
Long export or download	System sleep	Display sleep, screen lock
Presentation or video playback	Display sleep, screen saver	Nothing
Lid closed with an external display	System sleep with the lid closed	Screen lock
Remote session left on screen	Display sleep	Screen lock after a set idle period

The combination worth knowing about is allowing the display to sleep while the Mac itself stays awake. The work continues, the panel goes dark, and power draw drops. For anything that runs unattended, that is the setting to reach for rather than keeping the screen lit for hours with nothing watching it.

Automated cursor movement deserves a separate thought. It exists to defeat idle detection, and plenty of workplaces treat that behaviour as something to be discussed rather than assumed. Decide about it deliberately instead of switching it on because it is in the list.

Move repeat cases into triggers

If the same situation keeps making you start the same session, register that situation as a trigger and the manual step disappears. The listing names fifteen conditions: an external display connected, display mirroring active, a USB or Bluetooth device connected, a specific app running, a specific app running and frontmost, the battery charging or above a threshold, the power adapter connected or disconnected, a specific IP address, a specific Wi-Fi network, a Cisco AnyConnect VPN connection, specific DNS servers, headphones or another audio output in use, a specific drive or volume mounted, CPU utilisation above a threshold, and the Mac being idle beyond a threshold.

Start with exactly one. An external display connection is the most reliable first choice for anyone who docks a laptop, because the condition is unambiguous and the session ends the moment the cable comes out. For meeting-driven work, a specific app running and frontmost is tighter, since the session stops when the call window is closed rather than when the app quits.

Stacking conditions is where setups become hard to debug. With one trigger, a session that did not start has one possible cause. With four, you are testing combinations by hand while a call is already running. Add the second condition only after a week has shown you a case the first one misses.

Settings that are easy to miss

Several capabilities sit outside the main session flow and are simple to overlook on a first pass through the settings. Four of them earn their place.

Locking the screen after a period of inactivity turns the app into something closer to a security setting than a keep-awake one, and pairs well with sessions that prevent display sleep, since the screen can stay lit while still locking when nobody is there. Allowing the screen saver to run after a customisable idle period does something similar for machines in shared spaces.

Drive Alive keeps a drive active, which matters for external disks that spin down or disconnect during long transfers and leave a job half finished. Ending a session automatically when the battery gets low is the guard already mentioned, and it is the single setting that makes indefinite sessions safe on a laptop.

Custom notification sounds sound cosmetic and are not. A distinct tone for a session ending is information you receive without looking at the menu bar at all, which is the goal for anything running in the background.

When the app you want does not appear in the trigger list

A common stopping point: you go to build an app-based trigger, and the app you had in mind is not offered. Nothing is misconfigured. Apps distributed through the Mac App Store are sandboxed, and a sandboxed app cannot enumerate every process running on the machine.

The developer covers this with a separate helper, Amphetamine Enhancer, distributed as a disk image on GitHub rather than through the store. It costs nothing, is MIT licensed, and Apple has notarized the release. It requires Amphetamine 5.0 or later, and it adds two things: the ability to use all running processes with triggers and app-based sessions, and a fail-safe for closed-display mode.

Whether to install it comes down to which conditions you plan to use. Displays, networks, drives and power states are all handled by the main app alone. Only a trigger that depends on a specific process needs the helper. If you do install it, note the version somewhere, because the helper updates outside the store and nothing will prompt you when a newer one appears.

Closed lid on an Apple Silicon laptop

Working with the lid shut and an external display attached needs one extra step on Apple Silicon Mac laptops. Connecting or disconnecting a power adapter, or a display that supplies power, can make closed-display sessions behave in ways that were not intended.

The remedy is called Power Protect, and it is not bundled with the app. It consists of a script and a configuration file that you download and place yourself: the script into the Library/Application Scripts/com.if.Amphetamine folder inside your home directory, and the configuration file into /private/etc/sudoers.d. A single Terminal command then enables it.

The reason those steps are manual is stated in the project repository: Apple does not allow the app to install the script and configuration file directly, so the work falls to the person setting it up. Since the second location holds system privilege configuration, read what you are placing there before you place it. If the lid stays open on your setup, skip this entirely, because it applies to one hardware and power combination and nothing else.

One hotkey removes most of the clicking

Hotkeys can be assigned to starting and ending sessions, and to enabling or disabling display sleep. Setting one turns a three step interaction, click the icon, open the menu, choose an item, into a single keystroke.

One is enough. The action used daily is the start and stop toggle, and the remaining options are configuration you touch rarely. Pick a combination that no other app has claimed, then confirm the state changed by glancing at the icon rather than reopening the menu.

There is also AppleScript support, which suits anyone who already scripts the start of a work session. Folding a session start into an existing script means the app effectively disappears from the daily routine, which is the outcome worth aiming at.

Once a hotkey exists, one reason for keeping the icon permanently visible goes away. The icon is now for reading state, not for clicking, and that distinction decides where it belongs on the menu bar.

What the icon shows, and what that costs in width

Two settings control what appears in the menu bar: a custom icon image, and an optional display of the session time remaining, supported in both twelve and twenty-four hour formats.

The timer is the expensive one. Digits sit next to the icon and widen the slot permanently, not only while a session runs. On a MacBook with a notch, that extra width is enough to push another item out of the visible area, and items that do not fit are not drawn at all. If you glance at the remaining time several times an hour, the width is earned. If you check it twice a day, switching it off gives the space back.

Custom icons are more useful than they look. When a dozen small monochrome glyphs sit side by side, finding the right one takes a beat longer every time. An icon with a distinct silhouette gets found instantly, which matters more as the bar fills. The features page covers what a menu bar manager for macOS can do with the icons you decide not to keep in front, and how it compares sets out where those tools differ from each other.

What to change first

Set the session default and the five allow or prevent choices before touching anything else, because every later decision depends on them. Then register one trigger, live with it for a week, and assign a single hotkey for start and stop. After that, count how often you actually click the icon: if the answer is close to zero, it belongs in a hidden group rather than in front of you, and Koffret is one way to make that split while keeping the icon reachable.