PTerm

A GPU-accelerated terminal emulator with built-in multiplexing and agent awareness.

About

PTerm is a terminal emulator written in Zig, built for developers who work with AI coding agents. It provides native tabs and splits, named layout presets, and an agent monitor that detects when tools like Claude Code are waiting for input.

Features

• GPU-accelerated rendering -- OpenGL 3.3 with instanced drawing, dual glyph atlases (grayscale text + color emoji), and procedural box-drawing shaders.
• Tabs and splits -- Create, close, resize, swap, zoom, and navigate panes with keyboard shortcuts. No external multiplexer needed.
• Layout presets -- Define named multi-tab, multi-pane layouts in your config and load them with a picker or --layout <name>.
• Agent monitoring -- Process-based detection: when the foreground process inside a pane matches the configured list (claude, codex, opencode by default), the pane is tracked as an agent. Recent PTY output = working; quiet + agent process = waiting (desktop notification fires).
• Agent focus mode -- Ctrl+Alt+A (or the A square at the leading edge of the tab bar) takes over the window with the first waiting agent pane at full size. Ctrl+Alt+N advances to the next waiting pane. Esc restores the tiled layout.
• HarfBuzz text shaping -- Ligatures, kerning, and font fallback chains. FreeType on Linux/Windows, CoreText on macOS.
• 8 built-in color themes -- default, dracula, solarized-dark, solarized-light, gruvbox-dark, nord, catppuccin-mocha, one-dark. Switch with a single config line.
• Scrollback search -- Ctrl+Shift+F to search buffer text with match counter and navigation.
• URL detection -- Hover-highlight clickable URLs, open with your OS handler.
• Config hot-reload -- Edit your config file and changes apply immediately.
• Update notifier -- The status bar shows a clickable Update vX.Y.Z in the bottom-right when a newer GitHub release is available; clicking opens the release page in your browser.
• Customizable keybindings -- Remap any action in TOML or use the built-in interactive keybinding editor (--set-keybindings).
• Cross-platform -- Windows (ConPTY), macOS (CoreText), Linux (fontconfig, X11/Wayland).

Installation

Pre-built binaries

Download from the latest release:

Platform	Package
Windows 10+ (1903)	.msi installer
macOS 12+	.dmg
Debian/Ubuntu	.deb
Fedora/RHEL	.rpm
Linux (portable)	.tar.gz

Note: PTerm is not code-signed. On macOS, right-click the app and select "Open" on first launch, or run xattr -cr /Applications/PTerm.app. On Windows, click "More info" then "Run anyway" if SmartScreen appears.

Build from source

Requires Zig 0.15.2:

zig build --release=safe

Binary output: zig-out/bin/pterm

On Windows, pass -Dconsole=true during development to keep a console window attached so stdout/stderr and panic traces are visible:

zig build -Dconsole=true

Release builds omit this flag so PTerm launches as a standalone GUI app.

Configuration

PTerm uses TOML for configuration. Generate a default config:

pterm --init-config

Config location on all platforms: ~/.config/pterm/config.toml (%USERPROFILE%\.config\pterm\config.toml on Windows).

Configuration is loaded in layers -- each layer overrides the previous:

1. Built-in defaults
2. Config file
3. PTERM_* environment variables
4. CLI flags

Example config

theme = "dracula"

[font]
family = "JetBrains Mono"
size = 14.0

[window]
cols = 120
rows = 40
opacity = 0.95

[cursor]
style = "bar"       # block, bar, underline
blink = true

[scrollback]
lines = 50000

[shell]
program = "/bin/zsh"
args = ["--login"]

[bell]
mode = "none"       # visual, sound, both, none

[agent]
enabled = true
preset = "broad"    # conservative, broad
notifications = true
suppress_when_focused = true
custom_patterns = ["my-custom-tool>"]

[url]
enabled = true

[status_bar]
visible = true

You can also import shared base configs:

import = ["base.toml"]
theme = "nord"

Themes

Set the theme key at the top level. Available built-in themes:

default dracula solarized-dark solarized-light gruvbox-dark nord catppuccin-mocha one-dark

Individual colors can be overridden under [colors], [colors.normal], [colors.bright], and [colors.ui] -- overrides take precedence over the active theme.

Keybindings

All actions are rebindable. Set them under [keybindings] in your config:

[keybindings]
split_horizontal = "ctrl+d"
split_vertical = "ctrl+shift+d"
new_tab = "ctrl+t"

Set an action to "none" to unbind it. Clipboard keys (Ctrl+C/Ctrl+V) are reserved and cannot be overridden.

Default keybindings

Action	Shortcut
New tab	Ctrl+Shift+T
Close tab	Ctrl+Shift+W
Next tab	Ctrl+Tab
Previous tab	Ctrl+Shift+Tab
Go to tab 1-9	Alt+1 ... Alt+9
Go to last tab	Alt+0
Move tab left/right	Ctrl+Shift+PageUp/PageDown
Split horizontal	Ctrl+Shift+H
Split vertical	Ctrl+Shift+V
Close pane	Ctrl+Shift+X
Focus pane (direction)	Ctrl+Shift+Arrow
Resize pane (direction)	Ctrl+Alt+Arrow
Swap pane (direction)	Ctrl+Alt+Shift+Arrow
Zoom pane	Ctrl+Shift+Z
Equalize panes	Ctrl+Shift+E
Rotate split	Ctrl+Shift+R
Break out pane	Ctrl+Shift+B
Search	Ctrl+Shift+F
Scroll page up/down	Shift+PageUp/PageDown
Scroll to top/bottom	Ctrl+Shift+Home/End
Layout picker	Ctrl+Shift+L
Toggle agent tab marker	Ctrl+Shift+A
Agent focus mode toggle	Ctrl+Alt+A
Agent focus next waiting	Ctrl+Alt+N
Change shell	Ctrl+Shift+S
Font size +/−/reset	Ctrl+= / Ctrl+- / Ctrl+0
Copy / Paste	Ctrl+C / Ctrl+V

Layout Presets

Define named layouts under [layout.<name>] in your config. Each layout can have multiple tabs, each with multiple panes arranged via splits:

[layout.dev]

[[layout.dev.tab]]

[[layout.dev.tab.pane]]
dir = "~/project"
cmd = "nvim"

[[layout.dev.tab.pane]]
dir = "~/project"
split = "right"
ratio = 0.4

[[layout.dev.tab]]

[[layout.dev.tab.pane]]
dir = "~/project"
cmd = "npm run dev"

[[layout.dev.tab.pane]]
dir = "~/project"
cmd = "npm test -- --watch"
split = "down"
ratio = 0.5

Load a layout at startup:

pterm --layout dev

Or press Ctrl+Shift+L at any time to open the layout picker. Press Enter to merge the preset's tabs into the current session, or Shift+Enter to replace existing tabs with the preset.

Each pane supports:

Field	Description
dir	Working directory (~ expanded)
cmd	Startup command
split	"right" or "down" (omit for the first pane)
ratio	Split ratio, 0.0--1.0 (default 0.5)
shell	Per-pane shell override
shell_args	Shell arguments

CLI Reference

pterm [options]

  --config <path>       Config file path
  --layout <name>       Load a named layout preset
  --font-size <float>   Override font size
  --title <string>      Window title
  --cols <int>          Initial columns
  --rows <int>          Initial rows
  --working-dir <path>  Working directory

  --init-config         Generate default config file
  --dump-config         Print full default config
  --check-config        Validate config file
  --set-keybindings     Interactive keybinding editor

  --version             Print version
  --help                Show help

Requirements

Platform	Minimum	Notes
Windows	10 v1903+	ConPTY pseudo-terminal support
macOS	12 (Monterey)	CoreText font rendering
Linux	glibc 2.35+	fontconfig, OpenGL 3.3, X11 or Wayland

License

PTerm is released under the MIT License.