Features

What pal does on its own, built into the app: the clipboard recorder, text expansion, the window switcher, the sidebar, keeping windows below a bar, mouse and trackpad tweaks, keycast. A feature runs whether or not the panel is open, cannot be uninstalled, and is not an extension: extensions are the palettes, bar items and routes you install (Extensions). Why the line is drawn there: docs/design/model.md.

Settings › Features has a card for each: what it is doing (on, off, the permission it waits on), its switch, and its settings unfolding under it. The file keeps each in [features.<id>]:

[features.expansion]
enabled = true
prefix = ";"

[features.mouse]
middle_click = true
reverse_mouse = true

[features.keycast.hotkeys]
toggle = "ctrl+alt+k"

Commands

Every yes/no setting of a feature is a command, and some features have commands of their own (keycast's Start and Stop). A command is a row at the root (type reverse and Enter on Reverse scrolling on the mouse flips it; the tag says on or off, the HUD what it became), a pal command and a link, and it takes a hotkey:

pal command mouse.reverse_mouse           # flip it
open pal://commands/keycast.toggle        # start or stop keycast

[features.mouse.hotkeys]
reverse_mouse = "ctrl+alt+r"

Settings › Features lists each card's commands with a hotkey field under the card's settings. A feature's headline switch (Text expansion, Keep below the bar) is named after the feature: Text expansion, on or off.

Clipboard history

Records what you copy (text, images, files, links, colours) so the Clipboard History palette can list, search and paste it again (Palettes). On from launch; app/src-tauri/src/clipboard.rs over pal_core::clipboard, the history a SQLite database under the data directory, nothing leaving the machine. What is never recorded, and how retention runs, is on the palette's page.

All three are read when pal starts. On Linux the source app of a copy is not known (neither X11 nor Wayland's data-control protocol says who owns the selection), so exclude_apps has no effect there.

Text expansion

On macOS, a snippet's keyword typed in any other app is replaced by its text in place: type ;sig in a mail and the signature lands where the keyword was, placeholders filled, the clipboard left as it was. Off by default. The snippets are the ones the Snippets palette edits (Palettes); they belong to this feature (storage/expansion.json), and the palette reads and writes them through core/snippets.{list, set}.

How it works (pal_core::expansion, app/src-tauri/src/expansion.rs): pal watches the keys typed in other apps (an NSEvent global monitor, which needs Input Monitoring for pal) and keeps the last 64 characters typed in the app in front; when they end in the prefix and a keyword, it deletes what was typed with that many backspaces, puts the filled text on the pasteboard marked concealed (clipboard managers and pal's own history skip it), pastes it, moves the caret back for a {cursor}, and 300 ms later puts the previous clipboard back (the backspaces and the paste need Accessibility, like Paste). Then the HUD says "Expanded Signature".

• The buffer empties on an arrow, Enter, Tab, Escape, a ⌘ or ⌃ combination, a change of app, and after an expansion; Backspace takes one character back, so a typo corrected still expands.
• A secure text field (a password field, sudo in a terminal) never expands, and neither do pal's own windows.
• {cursor} in the text: the caret lands there after the paste. A paste from the panel drops it. {selection} is left as written: the selection while a keyword is being typed is the keyword.
• A snippet saved or edited in the panel expands on the next keystroke.
• Linux: not available (Wayland hands key events to the focused client only, and X11 has no portable tap either).

Window switcher

Cmd+Tab's shape over the Windows palette: hold the chord to step through the windows, let go to switch; a quick tap goes back to the window you were in before, without painting anything. The chord is the Windows palette's hold ([palettes.windows] hold, alt+tab suggested by the palette; any palette can have one, Keyboard); the design is docs/design/switcher.md. cmd+tab as the chord goes through an event tap and needs Input Monitoring.

Sidebar

A live palette docked to a screen edge: it peeks the moment the pointer touches the edge, and cmd+N runs row N. Off until a palette is picked; the card's switch puts the Windows palette there. Its keys, [features.sidebar], are listed in Config.

Keep below the bar

macOS: a window that opens, zooms or is dragged under a bar drawn over a hidden menu bar (sketchybar), where macOS reserves nothing, is moved down clear of it, its bottom edge kept; pal's own window layouts leave the strip free too. One accessibility observer per running app sees windows created, moved and resized; a window being dragged is moved when it is let go; full-screen and minimised windows, panels and popovers are left alone (app/src-tauri/src/reserve.rs). Needs Accessibility.

Mouse & Trackpad

A three-finger tap or click on the trackpad as a middle click, and scrolling reversed for the trackpad, the mouse or both, each axis apart (what MiddleClick and Scroll Reverser do), and the pointer hidden while it is idle, macOS only.

An active event tap on a thread of its own (app/src-tauri/src/mouse.rs) turns a left click made with three fingers on the trackpad into a middle click (its drag and release follow) and negates the scroll deltas on the reversed axes; MultitouchSupport counts the fingers and tells a tap (three fingers down and up within 0.3 s, not moved, no fourth, no press) from a swipe. A scroll is the mouse's when it comes in a wheel's notches or under fewer than two fingers (a Magic Mouse); momentum keeps the source of the scroll it follows. Devices are listed again every 3 s, so a trackpad paired later and a wake are picked up. Turning a switch on asks for Accessibility when it is missing and starts on the grant. The card says "No trackpad is being read" when the middle click is on and no trackpad is found.

The pointer is hidden in every app once it has not moved or clicked for hide_pointer_after seconds, never while a button is held, and comes back on the first move or button down; a scroll does not bring it back. macOS hides the pointer only for the app in front, so pal marks its window-server connection SetsCursorInBackground (private, as Cursorcerer does). The idle time is read when it could have run out, not polled, and the tap that sees the pointer move is enabled only while it is hidden. Keycast's cursor ring hides with it. A pal that exits leaves nothing hidden.

Keycast

Keystrokes and clicks drawn over the screen for a recording or a screen share (KeyCastr, Keyviz), macOS only. Commands: Start keycast (Stop keycast while it runs, then with an on tag), Keycast: keys only, Keycast: cursor only, Keycast: keys and cursor (start in, or switch to, that mode), and the toggles of its yes/no settings. Starting and stopping from the panel hide it first and the HUD says Keycast on: keys and cursor, so the panel is never in the recording.

What it draws (app/src-tauri/src/keycast.rs, the overlay window; the caps and the feed are pal_core::keycast): the recent entries as one row along the chosen edge, oldest on the left and newest on the right, each a frosted capsule. Plain typing runs together as text in the capsule as typed (hello world, a caret while the run still takes characters: the next character within a second joins it, up to 24, and a pause, a shortcut or a named key starts the next); a shortcut is caps with a lip, ⌃ ⌥ ⇧ ⌘ as glyphs drawn a shade lighter than the key they chord with (⌘⇧S); a named key its symbol (↵ ⇥ ⌫ ⌦ esc ← ⇞ F5); a repeat within the hold folded into one entry with a ×3 badge on its corner; a click with modifiers ⌥ click. An entry fades and settles with age and is gone hold seconds after its last press, max kept. With gestures on the strip also names what the trackpad and the wheel do: scroll ↓ (sized by how far in three steps), pinch out +35%, rotate ↻ 12°, swipe ←, smart zoom; only what AppKit hands a global monitor, so the system's three- and four-finger swipes never show. A ring around the cursor in the ring_color (smaller while a button is down) and a ripple on every click, a filled disc for the left button, a hollow amber ring for the right, grey for the middle. The overlay is a full-screen pass-through window on the display under the cursor, following it across displays; the strip keeps clear of the menu bar and the Dock. Nothing typed shows while a secure text field has the keyboard (a password, sudo), nor what is typed into pal itself; with shortcuts_only plain typing stays off the screen and only a key with cmd, ctrl or alt or a function or navigation key shows.

States keycast/active and keycast/mode. The bar item keycast/active, the feature's own: a red record dot with the mode (keys + cursor) while it runs, hidden otherwise (a rule on colours it; show = "always" keeps a muted dot). The popover: the three modes as tiles (k, c, b), the shortcuts-only (s) and gestures (g) switches, backspace stops, o opens these settings.

Input Monitoring: starting asks once when it is missing (as text expansion does; the two share one NSEvent global monitor), and the Overview lists the permission while keycast is on. Linux: not available (no portable input tap).

Rendered from docs/features.md in the pal repo, 2026-09-30.