Actions
A mapping runs an action. Actions are either built in or yours. The Actions page lists both; built-ins cannot be edited, but any of them can be mapped.
Built-in actions
| Action | ID |
|---|---|
| Left, Right, Up, Down | builtin.move_left, builtin.move_right, builtin.move_up, builtin.move_down |
| Word Forward, Word Back | builtin.word_forward, builtin.word_back |
| Home, End | builtin.line_start, builtin.line_end |
| Up 10 Lines, Down 10 Lines | builtin.jump_up_10, builtin.jump_down_10 |
| Backspace | builtin.backspace |
| Next Line | builtin.new_line |
| Insert Quotes | builtin.insert_quotes |
| Escape | builtin.escape |
| Toggle Caps Lock | builtin.toggle_caps_lock |
| Do Nothing | builtin.noop |
| Normal Key | builtin.passthrough |
The IDs are permanent: a mapping that refers to one keeps working across versions.
Custom actions
Click New Action… on the Actions page, or define an action inline in the mapping editor. The types are:
| Type | What it does |
|---|---|
| Key combo | Sends one key with any of ⌃ ⌥ ⇧ ⌘. |
| Jump | Moves the cursor several lines in one direction. |
| Open app | Opens or brings forward an app, chosen from Applications. |
| Shell command | Runs a command with /bin/sh. Needs your approval; see below. |
| Hold modifier | Keeps one modifier pressed for as long as you hold the trigger, like push-to-talk. Use it with a Caps + key trigger. |
| Switch Input Source | Selects one specific installed input source. Available in the mapping editor. |
The mouse, scrolling, sleep, clipboard-slot, and media actions used by the Classic layout appear under Mouse & system. You can map them to other keys, but not create new ones.
An action that a mapping uses cannot be deleted; the Actions page names the mappings to remove first.
Shell commands and trust
Saving a Shell command asks Trust this action? A trusted command runs with your user privileges. It can change files and use the network, and neither Pause nor Undo can reverse what it has done. Click Trust & Save to keep it. The same question appears for the Sleep Mac and Sleep Display actions.
A command is never trusted by accident:
- Editing the command text removes its trust until you approve it again.
- Every command and sleep action in an imported configuration arrives switched off, shown as "Off · needs review". Open it in the editor and save it to approve it.
- A command that is not trusted does not run, whatever the configuration file says.
Commands run in the background with their output discarded; Capslock does not log what they print.
Switching input sources
The default layout's ⇪ Space sends ⌃Space, so macOS uses whatever shortcut
you set for "Select the previous input source". To jump straight to one input
source instead, map a key to Switch Input Source and pick it.
Some Chinese, Japanese and Korean input sources do not take effect reliably when switched directly. Settings › Input sources offers two workarounds for Caps + key mappings that switch input source:
- Simulate shortcut presses "Select the previous input source". Reliable before macOS 26; it needs that shortcut turned on in System Settings.
- Switch focus briefly moves focus so the new input source takes hold. Better on macOS 26; it does not work in floating windows.