Ghostty Terminal Config

Ghostty is a GPU-accelerated terminal written by Mitchell Hashimoto, released as open-source in late 2024 after two years of private beta. The pitch — and what it delivers — is "a native, fast, opinionated terminal that just works." On macOS, it feels indistinguishable from a native AppKit terminal app (because it is one — Ghostty uses the platform-native windowing layer where possible), but the cell renderer hits 120fps consistently and the latency-to-first-frame on launch is under 80ms.

This entry covers the config for a tmux-heavy, Vim-flavored, dark-mode workflow. Ghostty's config language is a flat key-value format — one option per line, comments with #, no nesting, no sections. That simplicity is intentional: there's no "where in the file does this go" question, and grep against the config tells you everything.

#// Where the Config Lives

Ghostty reads ~/.config/ghostty/config on macOS and Linux. There's no GUI, no preferences pane — every setting is in that one file, and the app picks up changes on the fly via ghostty --reload-config or by re-opening a window. For a multi-machine setup, the file checks into dotfiles cleanly because there's no embedded state.

font-family = "JetBrains Mono"
font-size = 14
font-thicken = true
adjust-cell-height = 10%

font-thicken = true applies a subtle thickness boost that compensates for the way macOS's font-smoothing works on retina displays — without it, Ghostty's font looks slightly thinner than the same font in iTerm or Terminal.app. adjust-cell-height = 10% gives lines a bit more breathing room, which makes long sessions easier on the eyes without significantly reducing the visible row count.

#// Theme

Ghostty ships with hundreds of built-in themes (every popular palette you've ever seen, plus the Base16 set). Pick one with a single setting:

theme = "catppuccin-mocha"
background-opacity = 1.0
window-padding-x = 12
window-padding-y = 10
window-padding-balance = true

background-opacity = 1.0 (fully opaque) is the right default — transparency in a terminal is aesthetically tempting but practically distracting. The padding settings give the cell area a small margin from the window chrome, which makes the cursor at column 1 feel less crowded against the window edge. window-padding-balance = true ensures the padding is symmetric even when the cell math doesn't divide evenly into the window size.

#// True-Color and tmux

For tmux to render 24-bit colors correctly under Ghostty, Ghostty's TERM value has to be recognized by tmux's terminal-overrides. Ghostty defaults to xterm-ghostty as TERM — set tmux to recognize it and you're done:

term = "xterm-256color"

The simplest fix is the line above — tell Ghostty to advertise xterm-256color as its TERM, which every tool on the planet already understands. The alternative is to teach tmux about xterm-ghostty in tmux.conf (set -ag terminal-overrides ",xterm-ghostty:RGB") — both work, the override-the-TERM approach is one line in one file and breaks nothing.

#// Keybindings That Play Nice with tmux

By default, Ghostty binds ⌘+T for new tabs, ⌘+W for close tab, and a handful of ⌘+arrow shortcuts. Most of these are fine. The ones that conflict with tmux are the split-pane and tab-switching keys — tmux already handles splits and windows, and the Ghostty equivalents create a confusing two-layer hierarchy. Disable them at the Ghostty level:

keybind = cmd+t=unbind
keybind = cmd+shift+t=unbind
keybind = cmd+d=unbind
keybind = cmd+shift+d=unbind
keybind = clear_default=ctrl+tab
keybind = clear_default=ctrl+shift+tab

The result is that Ghostty becomes a single-window, single-tab terminal — exactly what it should be when tmux is doing the multiplexing. The Ctrl+Tab unbind frees the keystroke for whatever shell-level binding wants it (I use it for fzf history search).

#// Shell Integration

Ghostty has optional shell integration that powers a few QoL features — semantic prompts, smart copy/paste of multi-line shell commands, and accurate "current working directory" reporting for the macOS proxy icon. Enable it in one line:

shell-integration = "detect"
shell-integration-features = "cursor,sudo,title"

detect auto-picks the right integration for your shell. The features list enables the bits I find useful and disables the ones I don't (shell-integration-features = no-sudo if you find the sudo-prompt highlighting distracting).

#// Performance Settings

Ghostty's performance defaults are sensible, but a couple of overrides matter for tmux + scrollback-heavy use:

scrollback-limit = 100000
copy-on-select = "clipboard"
mouse-hide-while-typing = true
mouse-shift-capture = false

A 100,000-line scrollback buffer costs ~12MB of RAM and saves you the next time you scroll back two hours looking for an error. copy-on-select = "clipboard" mirrors tmux's set -g set-clipboard on behavior — selecting text with the mouse immediately puts it in the system clipboard, no Cmd+C needed. mouse-shift-capture = false lets Shift+drag bypass tmux's mouse handling for cases where you want a native OS selection instead of a tmux-aware one.

#// The Install

brew install --cask ghostty puts the app at /Applications/Ghostty.app. The config file doesn't exist by default — create ~/.config/ghostty/config with the artifact below, launch the app, and you're in a fully-themed terminal at first paint. There's no first-launch wizard, no "pick a profile," no settings to migrate. That minimalism is the entire pitch.