Sentinel

Keep your Mac awake while Claude Code, Codex, Claude Desktop, or Claude Cowork is doing work.

Sentinel is a macOS menu bar app and CLI helper. It prevents system sleep while supported coding agents are active, including lid-closed sessions, then restores normal sleep behavior when the work is finished.

What It Supports

• Claude Code CLI through Claude Code hooks.
• Codex CLI through Codex hooks.
• Claude Desktop and Claude Cowork through process monitoring.
• Lid-closed keep-awake behavior through pmset disablesleep.
• Optional privacy lock for CLI sessions using the real macOS lock screen.
• Claude Desktop/Cowork stays awake without privacy-locking by default, so Chrome/computer-use tasks have the best chance to keep using the graphical session.

Important Behavior

The target state is awake, not asleep.

• If the Mac is awake and Sentinel is running, active agents can continue.
• If the Mac is locked but awake, CLI agents and many background tasks can continue.
• If the Mac is actually asleep, local Claude/Codex/Cowork work stops.
• If Claude Desktop/Cowork needs Chrome UI control, avoid auto-locking Claude Desktop. This is the default.

Installation

Option 1: DMG Installer

1. Download the latest DMG from the releases page: Sentinel latest release
2. Open the DMG.
3. Drag Sentinel.app into /Applications.
4. Launch Sentinel.app.
5. Approve the setup prompt. Administrator permission is required to configure pmset.
6. Restart Claude Code, Codex, or Claude Desktop.

Option 2: Homebrew

brew tap CharlonTank/tap
brew install sentinel
sentinel install

Option 3: Build From Source

git clone https://github.com/Aravindargutus/sentinel.git
cd sentinel
git checkout main
cargo build --release
./target/release/sentinel install

After installation, launch the app:

open /Applications/Sentinel.app

Required macOS Permissions

Sentinel may ask for these permissions depending on enabled features:

• Administrator permission: required to configure passwordless pmset access.
• Input Monitoring: used for idle detection and dictation shortcuts.
• Accessibility: used for dictation text injection and related automation helpers.
• Microphone: used only by the dictation feature.

For keep-awake behavior, the most important setup step is sentinel install, which configures pmset access and agent hooks.

How It Works

Claude Code and Codex

sentinel install adds lifecycle hooks:

• When an agent starts work, hooks call sentinel start.
• Sentinel records the active agent PID.
• The menu bar app/background agent disables sleep while any active PID exists.
• When the agent finishes, hooks call sentinel stop.
• Sleep is re-enabled only when no protected work remains.

Claude Desktop and Cowork

Claude Desktop does not use the same hook lifecycle as Claude Code. Sentinel monitors the main Claude.app process instead.

• When Claude Desktop is running, Sentinel treats it as protected activity.
• Sleep stays disabled while Claude Desktop is open.
• When Claude Desktop quits, Sentinel restores normal sleep if no CLI agent sessions are active.

Privacy Lock

Privacy lock uses the real macOS lock screen:

CGSession -suspend

Defaults:

• CLI agent sessions: privacy lock enabled.
• Claude Desktop/Cowork: privacy lock disabled.
• Idle delay: 60 seconds.

This default avoids interrupting Claude Desktop tasks that need an unlocked graphical session, such as Chrome/computer-use workflows.

Usage

Run the menu bar app:

open /Applications/Sentinel.app

Check current state:

sentinel status

List active sessions as JSON:

sentinel list

Clean up stale interrupted sessions:

sentinel cleanup

Force reset sleep prevention:

sentinel reset

Uninstall:

sentinel uninstall

Keep Whisper/dictation model data during uninstall:

sentinel uninstall --keep-model

Settings

Open settings from the menu bar app or run:

sentinel settings

Available settings include:

• Enable or disable sleep prevention.
• Enable or disable Claude Desktop monitoring.
• Enable or disable privacy lock.
• Choose whether privacy lock applies to CLI agents.
• Choose whether privacy lock applies to Claude Desktop.
• Set the privacy-lock idle delay.
• Configure speech-to-text language and vocabulary.

Settings are stored in:

~/Library/Application Support/Sentinel/settings.json

Development

This repository uses the main branch.

Run tests:

cargo test --workspace

Format code:

cargo fmt

Build release binary:

cargo build --release

Build a local DMG:

cargo xtask build-dmg --skip-notarize

Clean the local installed app/test state:

cargo xtask clean --keep-model

Full local test package flow:

cargo xtask complete-test --skip-notarize --keep-model

Limitations

Sentinel can prevent sleep, but it cannot override every macOS, hardware, power, or security policy.

It cannot guarantee work continues if:

• The Mac is already asleep before Sentinel is active.
• Battery dies or power is lost.
• macOS thermal protection forces sleep or throttling.
• Enterprise/security policy blocks pmset disablesleep.
• Claude Desktop is closed.
• A Chrome/computer-use task requires a visible unlocked display and macOS does not provide one while the lid is closed.

The intended reliable state is:

Agents active + Sentinel running + Mac awake = work can continue

License

MIT. See LICENSE.