Clamshell vs Insomnia: No Sudoers Rule, No pmset Switch

Verdict: pick Clamshell for Mac to keep a MacBook awake with the lid closed. It installs with no password and adds no sudoers rule, while Insomnia's installer writes a rule that lets your whole user account switch pmset disablesleep without a password. Clamshell never touches that system-wide setting. It is notarized by Apple, runs on macOS 14 and later, and its thermal protection cannot be switched off. Insomnia needs macOS 26 and describes itself as experimental.

No adminNo password, sudo rule or helper

No pmsetNothing system-wide left on

macOS 14+Insomnia needs macOS 26

Notarized7-day trial, then $9.99 once

Clamshell for Mac keeps a MacBook awake with the lid closed, on power or battery. No admin password, no sudoers rule, no monitor. Free for 7 days, then $9.99 once.

Download free trial

Apple Silicon, macOS 14+. Notarized by Apple. 3.6 MB. Or buy now, $9.99

Same closed lid, no sudoers rule.Clamshell overrides lid sleep with an unprivileged control only while you have it armed. Insomnia gets there by switching a system-wide sleep setting through a passwordless sudo rule its installer adds.

Insomnia is a free menu bar app for timed awake sessions, published on GitHub in September 2026 and widely shared in October. You enter days, hours and minutes, and the Mac stays awake until the timer ends. Around that it does a lot: on lid close it can freeze chat apps, mute audio and turn on Low Power Mode, and it can join an iPhone hotspot when the Wi-Fi drops. Clamshell for Mac is built for exactly one job: you arm it, close the lid, and it restores normal lid sleep when you disarm, quit or open the lid after a one-close arm.

For the closed lid itself, that focus is the difference. Clamshell does it without administrator access and without changing a system-wide setting. The details below show why.

Side-by-side comparison

Insomnia cells come from its GitHub README, install guide and releases, checked October 12, 2026. "Not stated" means we could not find it on those pages; it does not mean the feature is missing.

	Clamshell Recommended	Insomnia
Admin rights	None. No sudo, admin password, sudoers rule, kernel extension, driver or privileged helper.	The installer needs your password. It adds a sudoers rule that lets your user account, "not just Insomnia", run four `pmset` commands without a password.
How lid-closed works	Unprivileged IOKit clamshell sleep-state control plus an idle-sleep assertion while armed. Never changes `pmset` settings.	Switches `pmset -a disablesleep` through the sudoers rule, per its README.
What gets installed	One app.	The app, a `launchd` recovery agent that runs every minute, and the rule at `/etc/sudoers.d/insomnia`.
When it ends	Menu and Option-close arming cover the next close. Shortcuts and right-click arming last until you disarm. Restores normal lid sleep on disarm or quit; never kept across a restart.	When the timer you set runs out, or when you end it early. Opening the lid does not end the session.
Thermal safeguard	Always on. Serious or critical thermal pressure disarms toward normal lid sleep and blocks arming until cooled.	Heat rules turn on Low Power Mode when the Mac is seriously hot and end the session at critical heat. On by default; Settings can turn them off. They only work while the app runs.
After a crash or force quit	The lid change is never saved across a restart. The direct edition can relaunch after an unexpected exit when its crash-recovery agent is permitted.	The recovery agent tries to undo the session once its end time has passed. The README says recovery can fail, and that the agent does not watch battery or temperature.
Your other apps	Left alone.	On lid close, apps on the freeze list are paused with `SIGSTOP`. The list starts with Slack, WhatsApp and Discord. Audio is muted by default.
Built-in display	Stays black while closed, and agents can still use the screen. After an armed close it stays dark on reopen until the Mac is locked.	Display and keyboard light are set to zero on lid close and restored on lid open.
Lid closed, no display	Yes, on power or battery.	Yes, on power or battery.
Platform	Apple Silicon MacBooks, macOS 14 or later.	Apple Silicon, macOS 26 or later.
Signing	Notarized by Apple.	Ad-hoc signed and not notarized, per its install guide. macOS blocks the first launch until you allow it.
Install	Download the DMG from clamshell.dev, or get it on Setapp.	Paste a prompt into a coding agent, or download a zip with the GitHub CLI, verify it and run `install.sh`, or build from source.
Maturity	Version 1.4.22, released October 6, 2026.	Labelled experimental. First stable release, 0.1.0, on October 10, 2026, plus nightly prereleases.
Battery safeguard	Optional low-battery disarm at a level you choose, off by default.	Low Power Mode below 40% and session end below 10% by default. Both can be changed.
Agent awareness	No. Arm from scripts with `clamshell://arm` and `clamshell://disarm`, or Shortcuts actions.	Not stated. Sessions run on a timer. An optional extra can type `continue` into a tmux pane you mark after 90 seconds without a network.
Price	7-day free trial, then $9.99 once for 1 Mac or $19.99 for 3 Macs. 14-day money-back guarantee.	Free.
Source code	Closed source.	Open source, MIT.

How each app keeps a closed MacBook awake

A MacBook has two separate reasons to sleep. Idle sleep happens when nobody touches it; a power assertion, the thing caffeinate and most keep-awake apps hold, stops that. Lid sleep happens the moment the lid closes, and a power assertion alone does not stop it. Why caffeinate does not work with the lid closed covers this in detail.

Clamshell overrides lid sleep with an IOKit control that macOS lets an ordinary app use, so nothing asks for a password and nothing system-wide changes. Insomnia uses the system-wide pmset disablesleep setting. That setting needs root, so Insomnia's installer asks for your password once and writes a sudoers rule that makes these commands passwordless from then on:

/usr/bin/pmset -a disablesleep 1
/usr/bin/pmset -a disablesleep 0
/usr/bin/pmset -b lowpowermode 1
/usr/bin/pmset -b lowpowermode 0

Insomnia's README is open about what that means: the rule covers "your user account, not just Insomnia", and "any program running as you can use that rule too, so review it before you install". Our guide to what pmset disablesleep does explains the setting, and the undo guide shows how to check that it is off.

Three steps, no administrator. Clamshell arms with no password and changes lid sleep only while armed. Insomnia needs an administrator at install and leaves a passwordless sudo rule in place, which is a blocker on a managed work Mac.

Timer or lid: when the session ends

Insomnia is built around a countdown. You pick how long the Mac stays awake, and the README notes that opening the lid does not end the session. If the task takes longer than you guessed, you add time. If it finishes early, the Mac stays awake until the timer runs out or you end it.

Clamshell is built around the lid. Arm it from the menu or hold Option while closing the lid on supported Macs, and it covers that one close and ends by itself when you open the Mac again. For a longer stretch, right-click or Shortcuts arming stays on until you disarm, and a script can wrap a job with open "clamshell://arm" and open "clamshell://disarm". The Claude Code lid-closed guide has a full script, and the hooks recipe arms it only while a session runs.

Why Clamshell is the better pick

No administrator access at all. Insomnia's installer needs your password to write a sudoers rule. Clamshell asks for nothing, so it also works on Macs where you are not an admin.
No standing sudo rule. Insomnia's rule lets any program running as you turn system sleep off without a password, as its README says. Clamshell adds no rule, helper or daemon.
Nothing system-wide is left on. pmset disablesleep tells the whole Mac to ignore sleep. Clamshell's override exists only while armed, normal lid sleep returns on disarm or quit, and nothing is saved across a restart.
Thermal safety you cannot switch off. Serious or critical thermal pressure disarms Clamshell toward normal lid sleep and blocks arming until the Mac cools. Insomnia's heat rules are on by default and can be turned off in Settings.
It leaves your apps alone. Clamshell does not pause Slack, mute audio or change Low Power Mode.
Notarized, on macOS 14 and later. Insomnia's releases are ad-hoc signed and not notarized, and it needs macOS 26. Clamshell is notarized by Apple and runs on macOS 14, 15 and 26.
Built for the closed lid. The built-in display stays black while agents can still use the screen, and after an armed close it stays dark on reopen until the Mac is locked.
Nothing to configure. Arm, close the lid, and it works on power or battery, through plug and unplug. Try it free for 7 days, then pay $9.99 once, with a 14-day money-back guarantee.

Close the lid without a sudoers rule. Clamshell is free for 7 days, then $9.99 once for one Mac.

Download free trial

Apple Silicon, macOS 14+. Notarized by Apple. 3.6 MB. Or buy now, $9.99

Looking at other options? Compare Capsomnia and Sleepless, two more free apps that use pmset disablesleep, or see all of them in the keep-awake roundup.

Frequently asked questions

Does Insomnia for Mac need an admin password?

Yes, at install. Insomnia's README says the installer needs your password because it writes a sudoers rule at /etc/sudoers.d/insomnia. That rule lets your user account run four pmset commands without a password. Clamshell for Mac needs no sudo, admin password or privileged helper.

What is the difference between Insomnia and Clamshell?

Insomnia is a free, open-source menu bar app for timed awake sessions. It switches pmset disablesleep through a sudoers rule, and on lid close it can freeze chosen apps, mute audio and turn on Low Power Mode. Clamshell for Mac is a paid single-purpose app that keeps an Apple Silicon MacBook awake with the lid closed while armed, using an unprivileged system control with no admin rights.

Does Insomnia work on macOS 15 Sequoia or macOS 14 Sonoma?

No. Insomnia's README says it requires macOS 26 or later on an Apple Silicon Mac. Clamshell runs on Apple Silicon Mac laptops with macOS 14 or later.

Is Insomnia notarized by Apple?

No. Insomnia's install guide says its releases are ad-hoc signed and not notarized, and that macOS blocks the first launch of a downloaded copy until you allow it in System Settings. Clamshell is notarized by Apple.

Does Insomnia detect when Claude Code or Codex finishes?

Its README does not say so. Insomnia sessions run on a timer you set in days, hours and minutes, and you can add time or end early. Clamshell does not detect agents either; scripts arm and disarm it with clamshell://arm and clamshell://disarm or Shortcuts actions.

Is there an Insomnia alternative with no sudoers rule?

Clamshell for Mac. It keeps the lid closed without pmset, sudo, a sudoers rule, an admin password or a privileged helper, and restores normal lid sleep when you disarm or quit. It costs $9.99 once after a 7-day free trial.

If you are on macOS 26 and want a free, open-source timer that also pauses chat apps and mutes audio while the lid is shut, Insomnia covers that.

Ready to close the lid? Clamshell keeps your MacBook awake with no admin rights. Free for 7 days, then $9.99 once.

Download free trial

Apple Silicon, macOS 14+. Notarized by Apple. 3.6 MB. Or buy now, $9.99

Related guides

Sources checked October 12, 2026: Insomnia's GitHub README, install guide, lid-close notes and 0.1.0 release. Insomnia was not installed or run, so nothing here is a hands-on test of it. Projects change; check the repository before deciding. Clamshell details come from its own documentation and changelog. Clamshell is the publisher of this comparison and is not affiliated with Insomnia. Product names belong to their respective owners.