Capsomnia

Current version: 4.2.4

Capsomnia is a small macOS menu bar app that turns Caps Lock into a physical keep-awake switch for closed-lid MacBook work.

Turn Caps Lock on when local work should keep running. Turn Caps Lock off when you want normal sleep behavior back.

It is useful for AI agents, mobile access, and other long-running or remote work.

Capsomnia does not collect telemetry or require an account. Network use is limited to an optional daily update check that reads GitHub's public release information (off switch in Advanced Settings), downloading installers from GitHub when you choose to update or install CLI & Skill, and local gateway probes when "Keep hotspot connected" is enabled. Capsomnia sends no telemetry, identifiers, or personal data.

When this tiny light is on, your Mac stays awake.

What It Does

• Prevent all-caps typing (optional): when Capsomnia is on, Caps Lock no longer forces uppercase input. Shift still types uppercase letters.
• Caps Lock on: keeps AI agents and other work from being interrupted when the MacBook lid is closed. Remote operation through tools such as Codex Mobile remains possible. The Caps Lock light physically shows the current state.
• Custom toggle shortcut: turn Capsomnia on or off with another key combination even if Caps Lock is assigned elsewhere. The green Caps Lock light continues to show the current state.
• Auto-off timer (optional): choose a preset from 15 minutes to 8 hours or a custom duration from 1 minute to 24 hours. When time expires, Capsomnia turns off and releases sleep prevention. It immediately sleeps the Mac only if the lid is closed; an open or unknown lid state cancels the immediate sleep request.
• Caps Lock off: restores normal sleep behavior.
• Display behavior: by default, closing the lid puts the display to sleep while work keeps running. Enable "Keep display awake" to keep the display session available after the macOS idle time or closing the lid, so remote UI operation such as Computer Use can continue. While the lid is closed in this mode, Capsomnia temporarily lowers only the built-in display to minimum brightness to reduce power use and heat, then restores the exact previous brightness when the lid opens. External displays are not changed.
• Quitting the app restores normal sleep behavior.

Capsomnia is useful for long-running local jobs, AI coding agents, SSH sessions, builds, downloads, and unattended scripts.

Usage Notes

• Ensure sufficient airflow and use a stable power source.