Simple Terminal

Keep many terminals open at once, without losing track of them. Tabbed workspaces, a resizable grid of live shells, one-click layout presets, and a layout that survives a restart.

Built with Electron, node-pty and xterm.js. MIT licensed.

What it does

• Tabbed workspaces — each tab holds its own pane layout; double-click a tab to rename it
• A title bar on every pane — its name and directory, plus split-right, split-down, zoom and close buttons that act on that pane, whether or not it is the focused one
• Split any pane left/right or top/bottom; close one and the layout collapses cleanly
• Layout presets for 1, 2, 4, 6, 8, 9, 12 and 16 panes, plus Tidy to re-square the grid
• Drag the dividers to resize — the shell reflows as you drag
• Zoom a pane to fill the window and back, leaving the others running underneath
• Quick switcher (⌘P) — jump to any pane in any workspace by name or directory
• Find in terminal (⌘F), a jump-to-bottom button when you have scrolled up, clickable links
• Persistence — layouts, tab names and per-pane directories come back on launch
• Settings — font, size, theme (dark or light), shell, scrollback

A pane whose shell exits stays where it is and offers a Restart, so a stray exit never rearranges your grid. Only one instance runs at a time: a second launch focuses the window you already have rather than opening a rival that would overwrite your saved layout.

Installing it

macOS — download the .dmg for your Mac from the latest release: Simple Terminal-<version>.dmg for an Intel Mac, Simple Terminal-<version>-arm64.dmg for Apple Silicon. Open it and drag the app into /Applications.

The build is not code-signed, so the first launch needs its quarantine flag cleared — otherwise macOS reports it as damaged:

xattr -dr com.apple.quarantine "/Applications/Simple Terminal.app"

Then open it as normal. To keep it around, right-click its Dock icon and choose Options → Keep in Dock.

Or build it yourself

npm install
npm run dist

That produces release/Simple Terminal-<version>.dmg and release/mac/Simple Terminal.app. An app you built yourself opens without the quarantine step.

Shortcuts

Every shortcut is a native menu accelerator, so it fires even while a terminal has keyboard focus — no key has to be wrestled away from the shell.

Action	macOS	Windows / Linux
Split right	⌘D	Ctrl+D
Split down	⇧⌘D	Ctrl+Shift+D
Close pane	⌘W	Ctrl+W
Restart pane	⌘R	Ctrl+R
Zoom pane	⇧⌘↩	Ctrl+Shift+Enter
Move focus	⌥⌘ + arrows	Ctrl+Alt + arrows
Tidy layout	⇧⌘T	Ctrl+Shift+T
Layout preset	⌥⌘1–⌥⌘8	Ctrl+Alt+1–8
New tab	⌘T	Ctrl+T
Close tab	⇧⌘W	Ctrl+Shift+W
Select tab	⌘1–⌘9	Ctrl+1–9
Next / previous tab	⌃⇥ / ⌃⇧⇥	Ctrl+Tab / Ctrl+Shift+Tab
Quick switcher	⌘P	Ctrl+P
Find in terminal	⌘F	Ctrl+F
Clear terminal	⌘K	Ctrl+K
Bigger / smaller text	⌘+ / ⌘-	Ctrl++ / Ctrl+-
Settings	⌘,	Ctrl+,

Development

npm install
npm run dev        # hot-reloading development run
npm run build      # typecheck all three projects, then bundle
npm start          # run the built output
npm test           # unit tests plus a real-pty integration test
npm run typecheck  # types only
npm run dist       # package the macOS app

Needs Node 20+ and a toolchain that can build native modules (xcode-select --install on macOS). node-pty is rebuilt against Electron's ABI automatically after npm install.

Two things that are easy to trip over:

• node-pty must be unpacked from the asar archive when packaging. It loads a native binding and execs a spawn-helper, and neither works from inside an archive. asarUnpack in the electron-builder config handles it — and naming a files list at all replaces the default patterns, so node_modules has to be listed explicitly or the packaged app ships without it.
• A development run and an installed build share the same saved workspaces, because both resolve the same userData directory.
• npm run dist leaves node-pty built for the last architecture it packaged (arm64), which breaks the real-pty test on an Intel Mac. Run npx electron-builder install-app-deps to rebuild it for your own machine before npm test.

Regenerating the icon

build/icon.svg is the source artwork; it was drawn small-first, so that at 16px the prompt and the split still read while the output lines fall away into texture.

mkdir -p build/icon.iconset
for s in 16 32 128 256 512; do
  rsvg-convert -w $s       -h $s       build/icon.svg -o build/icon.iconset/icon_${s}x${s}.png
  rsvg-convert -w $((s*2)) -h $((s*2)) build/icon.svg -o build/icon.iconset/icon_${s}x${s}@2x.png
done
rsvg-convert -w 1024 -h 1024 build/icon.svg -o build/icon.png
iconutil -c icns build/icon.iconset -o build/icon.icns

How it is put together

src/main/         Electron main process — owns every pty, the store and the menu
  sessions.ts       SessionRegistry: create / write / resize / kill, keyed by session id
  store.ts          workspaces.json, written atomically, corrupt files quarantined
  menu.ts           the native menu and its accelerators
src/preload/      the only bridge to the renderer (contextIsolation on, no Node in the page)
src/renderer/     React UI
  layout/tree.ts    pure binary split tree: split, close, ratios, tidy, geometry, neighbours
  layout/presets    the 1–16 pane grids
  state/reducer     workspaces, panes and settings as one pure reducer
  components/       PaneGrid, TerminalPane, TabBar, Toolbar, QuickSwitcher, SettingsDialog
src/shared/       types, the preload API contract, preset sizes

Three decisions worth knowing:

• Panes are absolutely positioned from computed geometry, not nested in the shape of the layout tree. Re-parenting a live xterm would wipe its scrollback, so every terminal stays mounted under a stable key while the layout changes around it.
• The layout maths and the reducer are pure functions, with no Electron or React imports. That is why they can be tested directly, and it is where the tests are.
• Keystrokes typed before a pane's shell has started are buffered in the renderer and flushed once the pty exists. The main process ignores writes to an unknown session, so without the buffer those keystrokes would vanish.

Status

Version 0.1.0 — download it here. Built, run and tested on macOS (Intel). The arm64 build is cross-compiled from an Intel Mac and has not been run on Apple Silicon. The electron-builder config carries Windows and Linux targets, but neither has been built or tested yet.

Not in this version: command blocks (Warp-style collapsible per-command output) need OSC 133 shell integration and are their own piece of work; likewise a file-browser sidebar and remote/SSH sessions. Restored panes get fresh shells — ptys do not survive quitting the app.

Licence

MIT — see LICENSE.