What is Capsomnia?

Capsomnia is a free, open-source macOS utility that turns your Caps Lock key into a physical sleep-prevention switch. Flip it on, close the lid, and your MacBook stays awake — keeping AI agents, SSH sessions, builds, and downloads running uninterrupted. The app uses a lightweight, transparent approach: it runs pmset -a disablesleep 1 when Caps Lock is on and restores normal sleep when toggled off. The Caps Lock LED doubles as a clear status indicator. No accounts, no telemetry, and fully auditable source code under the MIT License.

Who it's for

• AI agent users – Keep long-running Claude Code, Codex, or other local agent tasks alive even after closing the MacBook’s lid.
• Remote workers and SSH users – Maintain SSH sessions and remote access to your Mac without unexpected sleep interruptions.
• Developers and power users – Let compiles, large downloads, and background processes finish on their own time while you move away from the desk.

Key features

Closed-lid continuity

Capsomnia keeps your MacBook working after the lid closes. It runs a single command (pmset -a disablesleep 1) to prevent sleep, so local jobs continue — and when remote login and networking are enabled, your Mac stays reachable over SSH.

Physical status via Caps Lock LED

The keyboard’s green Caps Lock light shows at a glance whether sleep prevention is active. No need to glance at the menu bar; the physical state is always visible on the key itself.

Custom shortcut flexibility

If Caps Lock is already assigned to another function, you can choose a different shortcut to toggle Capsomnia. While active, the Caps Lock light remains lit — so the indicator is still clear.