Fantastty

A macOS terminal app built on Ghostty (libghostty) with workspace-based session management and persistent tmux-backed sessions.

Download

Grab the latest signed and notarized DMG from Releases.

Requires macOS 15.0 (Sequoia) or later, Apple Silicon.

Features

• Workspaces — Each sidebar item is an independent workspace with its own tabs, notes, and metadata. Auto-generated names (e.g., "bold-falcon") keep things identifiable.
• Persistent sessions — Workspaces are backed by tmux sessions that survive app restarts. Quit and relaunch — everything is exactly where you left it.
• Tabs and splits — Multiple tabs per workspace, each with its own tmux session. Split panes within tabs.
• Notes panel — Attach timestamped notes to any workspace, manually or via terminal escape sequences. Editable with revision history.
• Workspace URLs — Track ticket and PR URLs per workspace, settable from the UI or via shell escape sequences.
• Workspace archiving — Archive workspaces you're not actively using. Unarchive them later to pick up where you left off.
• SSH sessions — Connect to remote hosts with tmux persistence on both ends.
• Attention indicators — Background workspaces light up when a bell rings or a command finishes.
• Shell integration — Automatic zsh integration for pwd tracking through tmux, plus the fantastty-note command for adding notes from the terminal.

Shell Integration

Fantastty includes a shell integration script that adds terminal commands:

source ~/.fantastty/shell-integration/fantastty.sh

# Add a note to the current workspace
fantastty-note "deploy finished"
fn "shorter alias works too"

Zsh integration (pwd tracking, escape sequence passthrough) is set up automatically when persistent sessions are enabled.

Building from Source

Prerequisites

• Xcode 16+
• Xcode Metal Toolchain (xcodebuild -downloadComponent MetalToolchain)
• Zig (see vendor/ghostty/build.zig.zon for the required version)
• XcodeGen (if regenerating the Xcode project)

Make sure Xcode is the active developer directory:

sudo xcode-select -s /Applications/Xcode.app/Contents/Developer

Build

# Clone with submodules
git clone --recursive https://github.com/blaine/fantastty.git
cd fantastty

# Build the GhosttyKit xcframework (takes a few minutes)
make xcframework

# Open in Xcode and build, or:
xcodebuild -scheme Fantastty -configuration Debug build

Release Build

The scripts/build-release.sh script builds a signed, notarized DMG:

# Full build with notarization (requires Developer ID certificate + notarytool credentials)
./scripts/build-release.sh

# Local testing without notarization
./scripts/build-release.sh --skip-notarize

Output lands in build/release/Fantastty.dmg.

Tagged GitHub Actions releases attach the notarized DMG and Sparkle appcast to GitHub Releases. Installed builds check https://github.com/blaine/fantastty/releases/latest/download/appcast.xml via the Check for Updates... app menu item.

Architecture

Fantastty is a SwiftUI app that uses Ghostty's libghostty as a static library for terminal rendering. Session persistence is handled through tmux:

• SessionManager orchestrates all workspaces, tabs, and tmux lifecycle
• Session represents a single workspace (sidebar item), keyed by a stable workspace ID
• TerminalTab represents a tab within a workspace, each backed by an independent tmux session
• TmuxManager handles tmux process creation, discovery, and cleanup

Workspace metadata (names, notes, URLs, tags) is persisted in ~/.fantastty/workspaces.json. Layout state (sidebar order, tab order, selections) is saved to ~/.fantastty/layout.json on quit and restored on launch.

License

MIT