English | 简体中文

in0

A macOS terminal that knows what your agent is doing.

in0 is a native macOS terminal multiplexer with workspaces, tabs, and split panes — built around a single deliberate idea: at any moment, you should know whether each of your AI coding agents is running, idle, waiting on you, or done. Powered by libghostty, rendered with Metal, written in Swift / SwiftUI / AppKit.

Features

• Workspaces → Tabs → Splits — Group terminals by project. Each workspace owns its tabs; each tab is a binary split tree you can cut horizontally or vertically. Switching tabs never kills your shell.
• Live agent status in the sidebar — A colored dot per workspace shows whether your Claude Code, Codex, or OpenCode session is running, idle, waiting on input, or finished. Driven by a simple Unix-socket hook protocol.
• Theme-aware chrome and settings — Semantic tokens drive the chrome, Settings writes a ghostty-style override config, and the sidebar/tab bar can follow the terminal background live.
• Layout persistence — Workspaces, tabs, split tree, and per-terminal pwd survive restart. Surfaces rebind by UUID; nothing depends on screen coordinates.
• No leaked frames between paradigms — SwiftUI owns the outer shell; AppKit owns NSSplitView and the terminal surface. The boundary is one NSViewRepresentable per surface. See docs/ARCHITECTURE.md for why.
• Source-available — read the source, build it locally, run it for personal or commercial work. See LICENSE for the precise terms.

System Requirements

• macOS 14.0 or later
• Apple Silicon strongly recommended
• Xcode 26+ with Metal toolchain (auto-fetched on first build)

Install

Download the latest signed, notarized DMG from Releases, open it, and drag in0 to Applications. The build is notarized, so a normal double-click launches it — no Gatekeeper right-click needed. in0 keeps itself up to date automatically via Sparkle.

Build from source

1. Toolchain

zig 0.15.2 is required (Homebrew's zig is 0.16, which doesn't compile ghostty):

mkdir -p ~/.local/zig
curl -fsSL https://ziglang.org/download/0.15.2/zig-aarch64-macos-0.15.2.tar.xz \
  | tar xJ -C ~/.local/zig --strip-components=1
brew install xcodegen gettext
xcodebuild -downloadComponent MetalToolchain   # ~700MB, one-time

2. Build libghostty

./scripts/build-vendor.sh

First run takes 30–60 minutes (clones ghostty source to /tmp/ghostty-src and builds a static library). Subsequent runs reuse the checkout.

3. Build & launch the app

./scripts/regen-project.sh
xcodebuild -project in0.xcodeproj -scheme in0 -configuration Debug build
open $(xcodebuild -project in0.xcodeproj -scheme in0 -configuration Debug \
       -showBuildSettings | awk -F' = ' '/CONFIGURATION_BUILD_DIR/ {print $2; exit}')/in0.app

4. Wire up an agent (optional)

Agent status is wired through bundled wrappers in Resources/agent-hooks/. zsh sessions launched from in0 auto-bootstrap through the app's ZDOTDIR shim; bash/fish users can copy the rc snippet from Agents → Copy … rc Snippet. Codex still requires enabling its experimental hook flag in ~/.codex/config.toml.

Background

in0 is a source-available terminal app built around the parts that matter most for this project: libghostty integration, SwiftUI ↔ AppKit boundaries, persistent tab/split state, and live coding-agent visibility.

This is a personal portfolio project, not a product. I'm not actively soliciting contributions; if you find something useful here, fork it (see LICENSE for fork terms).

License

IN0 Source-Available License — read, build, and run for personal or commercial work; don't redistribute, repackage, or train models on the source. ghostty itself remains MIT.