§ Feature

Keyboard remapping for macOS

Your keyboard has keys you never press and keys you reach for constantly. KeyMic swaps them. Right ⌘ becomes Forward Delete, Caps Lock becomes Left Control — whatever your hands actually want.

No daemon, no login item, no helper process

Karabiner-Elements works by installing a system-level driver and a background daemon. KeyMic handles almost everything with a single session-level CGEvent tap inside the app you already have running in the menu bar — no driver, no separate process to keep alive or debug.

One honest exception: Caps Lock. By the time a Caps Lock press reaches a session event tap, macOS has already toggled the lock state, so it cannot be intercepted there. Remapping it requires an HID-level mapping installed through hidutil — the same mechanism Karabiner-Elements and Hyperkey use. KeyMic uses that route only for Caps Lock sources, the mapping lasts for the current login session, and it is removed when you quit the app. Every other mapping stays on the event tap.

That is the trade. You get remapping in the same 4.5 MB binary that handles voice and clipboard, and you give up the deeper hooks a permanently-installed driver can reach.

What you can map

• Modifier to modifier — Caps Lock to Left Control is the classic, and the one case that goes through hidutil rather than the event tap. All of ⌘, ⇧, ⌥, ⌃, Caps Lock and fn are recognised as modifiers.
• Modifier to key — Right ⌘ to Forward Delete, so a full-size layout key you never use becomes the one missing from your compact keyboard.
• Auto-repeat — held keys repeat correctly when the target is a regular key, not just a single press.

Mappings are recorded by pressing the key rather than picking from a list, so you never have to know what a key is called internally.

Where the limits are

Being straight about this matters more than a feature list. KeyMic does modifier and key mappings. It is not a full Karabiner replacement: there is no complex-modification DSL, no per-device rules, no simultaneous-key or tap-versus-hold layers. If your setup depends on those, keep Karabiner. If it is a handful of sane swaps, KeyMic covers it without a daemon.

Permissions

Remapping needs macOS Accessibility permission — that is what makes an event tap possible. You grant it once, and you can revoke it in System Settings, after which remapping stops and everything else keeps working. The app is not sandboxed, which is a deliberate consequence of needing that tap; Security & Architecture explains the full permission model and exactly what leaves your machine.

Also in KeyMic: clipboard history and the secret vault, or see everything on one page.