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Bonfire

A tiny macOS menu bar app that keeps your Mac awake — even with the lid closed.

Built for long unattended runs: agent loops, builds, model training, big downloads.

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Features

• 🔥 Menu bar toggle — click a preset (30m / 1h / 2h / 4h), custom duration, or forever
• 🌙 Turn off display while keeping awake — press the lid-close button and walk away
• 🔌 Lid-close-aware — when plugged in, your Mac stays awake with the lid shut
• 🔋 Battery mode — opt-in advanced override (pmset disablesleep) lets the lid-closed-awake trick work on battery too
• 🛡️ Battery safety rail — auto-stops at a low-battery threshold (default 20%) so an unattended run can't drain your battery to zero
• 🔐 One password prompt, ever — the advanced mode installs a tiny sudoers fragment so subsequent uses are silent
• ⏱️ Smart timer — "Until 23:00" picks the next occurrence; if it already passed today, rolls to tomorrow
• 💤 Graceful exit — auto-restores normal sleep policy when the timer expires, you stop manually, or the app crashes

Install

Grab the latest Bonfire.dmg from Releases → double-click → drag Bonfire onto the Applications shortcut.

First launch: macOS Gatekeeper blocks ad-hoc-signed apps. Either:

• Right-click the app → Open → Open in the dialog that appears, or
• Run once:

  xattr -dr com.apple.quarantine /Applications/Bonfire.app

That's a one-time step. After the first launch macOS remembers.

Usage

Click the campfire icon in your menu bar:

Keep your Mac awake for a fixed time — click 30m, 1h, 2h, 4h, or open Custom ▾ to dial any duration. Bonfire flips to the burning view showing a live countdown. When the timer expires it stops automatically and your Mac returns to normal sleep behavior.

Keep your Mac awake indefinitely — click Keep awake. Click Stop when you're done.

Pre-emptively turn the screen off (while keeping the system running) — in the burning view, click Turn off display. Useful before closing the lid and walking away. Move the mouse or press a key to wake the screen again.

What happens while Bonfire is active

• Your Mac stays awake the whole time, even if you don't touch it.
• The screen may still dim or turn off on its own — that's fine, your Mac keeps running underneath.
• Closing the lid keeps it running too — but only when plugged in. On battery, closing the lid still puts your Mac to sleep, unless you opt into the advanced battery mode below.
• On battery, Bonfire stops itself when battery drops below your threshold (default 20%) so an unattended run can never drain to zero.
• The timer survives lid close, screen off, and your absence — it lives in the menu bar app's process, not in anything UI-bound.

Advanced: battery mode (lid closed, on battery)

By default, macOS forces sleep when you close the lid on battery — there's no way around this from a normal app. Bonfire offers an opt-in workaround:

1. Open Preferences… → toggle on Keep awake on battery with lid closed.
2. The next time you start a session on battery, Bonfire asks for your admin password once to install a small sudoers fragment.
3. From then on, lid-closed-on-battery just works, silently, forever — across app restarts and reboots.

The fragment grants the admin group passwordless access to exactly the two pmset commands Bonfire needs, nothing else:

%admin ALL = (root) NOPASSWD: /usr/bin/pmset -b disablesleep 0, /usr/bin/pmset -b disablesleep 1

To revoke at any time: sudo rm /etc/sudoers.d/bonfire-pmset.

⚠️ Battery still drains. The low-battery auto-stop rail still applies — Bonfire turns itself off when battery hits your threshold.

How it works

Two layers of awake-keeping that stack:

Layer	API	Effect	Privileges
Idle / system sleep	IOPMAssertion (PreventUserIdleSystemSleep + PreventSystemSleep)	Stops the system from idle-sleeping. On AC power this is enough to keep a closed lid awake.	None
Forced lid-close sleep on battery	pmset -b disablesleep 1 via passwordless sudo	Overrides macOS's hardware-level "lid closed on battery → sleep" policy.	Admin (one-time install)

Display dimming uses pmset displaysleepnow (no admin required).

Full design rationale and trade-offs: docs/design.md.

Building from source

Requires Xcode 15+ and Homebrew.

brew install xcodegen
git clone https://github.com/<your-user>/bonfire.git
cd bonfire
xcodegen
open Bonfire.xcodeproj

Or for a distributable build:

./scripts/build.sh
# → dist/Bonfire.app, dist/Bonfire.zip, dist/Bonfire.dmg

Run the full test suite:

xcodebuild -project Bonfire.xcodeproj -scheme Bonfire -destination 'platform=macOS' test

49 unit tests covering the state machine, timer math, preferences persistence, and IOKit wrappers.

Project layout

Bonfire/
├── BonfireApp.swift                @main entry
├── AppIcon.icns                    App icon (regenerate via scripts/make-icon.sh)
├── Core/
│   ├── BonfireDomain.swift         State enums
│   ├── BonfireController.swift     State machine (testable, mocked deps)
│   ├── AssertionManager.swift      IOPMAssertion wrapper
│   ├── PowerMonitor.swift          IOPS power source events
│   ├── Notifier.swift              UserNotifications wrapper
│   ├── BatteryAwakeBypass.swift    pmset + sudoers fragment installer
│   └── DurationCalculator.swift    "Until" rollover math
├── Support/
│   ├── Preferences.swift           @AppStorage-backed config
│   ├── LaunchAtLogin.swift         SMAppService wrapper
│   ├── IconRenderer.swift          Menu bar icon (PNG + fallback)
│   ├── Display.swift               pmset displaysleepnow
│   └── WindowAccessor.swift        SwiftUI ↔ NSWindow bridge
├── Views/
│   ├── PopoverView.swift           State router (idle vs burning)
│   ├── IdleLayout.swift            Quick presets + custom + forever
│   ├── BurningLayout.swift         Countdown + stop + display-off
│   ├── PreferencesView.swift       Settings window
│   └── InfoView.swift              "How it works" window
└── Resources/
    ├── burning.png                 Menu bar icon (burning state)
    └── idle.png                    Menu bar icon (idle state)

Architecturally every IOKit-touching component sits behind a protocol so the state machine can be unit-tested without actually putting the system to sleep.

Uninstall

Bonfire's footprint outside /Applications is minimal:

• ~/Library/Preferences/ai.dotwise.Bonfire.plist — user settings
• /etc/sudoers.d/bonfire-pmset — only if you enabled "Keep awake on battery with lid closed". Remove with:

  sudo rm /etc/sudoers.d/bonfire-pmset

• SMAppService login item — removed automatically when you delete the app

Known limitations

• Ad-hoc signed, not notarized. Gatekeeper warns on first launch; right-click → Open bypasses it.
• Battery + lid closed mode modifies system-wide pmset policy. If the app crashes mid-session, the next launch will silently reset it; if you remove the sudoers fragment manually, run sudo pmset -b disablesleep 0 to be safe.
• External display + lid closed without bypass already enters "clamshell mode awake" via macOS itself when on AC — Bonfire is redundant but harmless in that setup.

License

MIT. See LICENSE.