Installation

cornercase ships as a single binary for Linux and macOS, on x86_64 and arm64. Install it with the install script or with Homebrew; building from source is there for contributors and for platforms without a prebuilt binary.

Requirements

To install	You need
A prebuilt binary	Linux with glibc 2.35 or newer (Ubuntu 22.04 or later, and similar), or macOS. curl or wget for the install script.
From source	Linux or macOS, rustup, Zig 0.15.2 on your PATH, git, and network access for the first build. See From source.

Optional, for some features:

• git, for worktrees.
• gh, logged in with gh auth login, to browse GitHub issues.
• A coding agent such as Claude Code, Codex or Gemini CLI, to start agents on issues. See Agents for the full list.

Install

1. Run the install script:

   curl -fsSL https://usecornercase.dev/install.sh | sh

   It downloads the binary for your system from the latest GitHub release, puts it in ~/.local/bin and adds that folder to the PATH in your shell profile. Open a new terminal so your shell picks it up.

   Or, with Homebrew:

   brew install usecornercase/tap/cornercase

2. Check that it runs:

   cornercase --version

3. Open a terminal in a project folder and start it:

   cd ~/code/my-project
   cornercase

   The folder you start from becomes your first project. Continue with First steps.

From source

cornercase is built with Cargo. The build also compiles Ghostty’s terminal core, which is written in Zig, so you need a Zig compiler of exactly the right version next to Rust.

You need	Why
Linux or macOS	The only supported platforms. On macOS, install the Xcode Command Line Tools: xcode-select --install.
rustup	The Rust version is pinned in rust-toolchain.toml; rustup installs it by itself on the first build.
Zig 0.15.2 on your PATH	It builds Ghostty’s terminal core, which refuses any other Zig version.
git	To clone the repository.
Network access	Only for the first build, which downloads Ghostty’s sources.

Exactly Zig 0.15.2

Package managers such as Homebrew may ship a newer Zig. If zig version doesn’t print 0.15.2, download that release from ziglang.org/download, unpack it and put its folder first on your PATH.

1. Check that Zig is the right version:

   zig version
   # 0.15.2

2. Clone the repository:

   git clone https://github.com/usecornercase/cornercase-terminal.git
   cd cornercase-terminal

3. Build and install the cornercase binary:

   cargo install --path . --locked

   The first build takes a couple of minutes: it fetches Ghostty’s sources and compiles them. Cargo puts the binary in ~/.cargo/bin, which rustup already added to your PATH.

Building offline

If you already have a checkout of Ghostty, point GHOSTTY_SOURCE_DIR at it before building and the download is skipped.

Update

cornercase updates itself. When the server starts, and then every hour, it asks GitHub for the latest release. That is a single request to GitHub’s API (plus the changelog once a new version is out); nothing about you or your projects is sent.

When a newer version is out, a toast says a new cornercase is out and a button with the new version, such as ↑ 0.2.0, appears at the right end of the Settings row in the sidebar (in a small terminal, in the same row of the menu’s footer). Click it:

1. The Update dialog tells you which version is out and which one you have, and what is new since yours: the notes of every version in between, newest first, so nothing is missed when you skipped a few. Scroll long release notes with the wheel or ↑ ↓.

2. Click update. cornercase downloads the binary for your system, checks it against its checksum, makes sure the new binary runs on this machine, and only then replaces the old one. If something fails, the error shows in red, the old binary stays, and the button becomes try again.

3. Click restart now. Before you do, the dialog says what is running and will stop: how many agents are working or waiting for you, and which other programs run in which project, or that nothing is running. cornercase saves your session, restarts the server on the new binary, and every attached terminal reopens on it. Your projects, workspaces, tabs and splits come back, but running programs don’t survive: each pane gets a new shell in its folder, so an agent at work is stopped. Claude Code and Codex then resume their conversations in their tabs.

Not ready to restart? Click later: the old version keeps running, and the sidebar button becomes ↻ restart for later. The next natural restart of the server, after cornercase kill-server or a reboot, also starts the new version, and running cornercase from another terminal against the old server asks whether to restart it (see Command line).

From the command line

Right after a release, you don’t have to wait for the next check. Run this from any shell, even inside cornercase:

cornercase update

It installs the latest release the same way, then asks whether to restart the server. Add --yes to skip the question, --when-idle to restart only once no agent is working, or --check to only see whether a newer version is out. See Command line.

When cornercase can’t update itself

When cornercase can’t replace its own binary, because Homebrew installed it, because you can’t write to its folder, or because it doesn’t know your platform, the dialog shows the command to run instead, with a copy command button, and cornercase update prints it:

brew update && brew upgrade cornercase                # Homebrew
curl -fsSL https://usecornercase.dev/install.sh | sh  # everything else

To turn the check off, set settings → UI → check for updates to never, or check_updates to false in config.json.

Builds from source

Pull the latest changes and install again; the next cornercase offers to restart the old server:

cd cornercase-terminal
git pull
cargo install --path . --locked

A build from source checks for updates too, and updating from the app or with cornercase update replaces it with the prebuilt binary. To stay on your own builds, turn the check off. Builds made with cargo run never check, and refuse cornercase update.

Uninstall

Stop the server, then remove the binary the way you installed it:

cornercase kill-server
rm ~/.local/bin/cornercase    # install script
brew uninstall cornercase     # Homebrew
cargo uninstall cornercase    # from source

The install script also added ~/.local/bin to the PATH in your shell profile; you can leave that line, other programs install there too.

Then remove what cornercase saved, if you don’t want to keep it:

rm -rf ~/.config/cornercase ~/.local/state/cornercase

If you set XDG_CONFIG_HOME or XDG_STATE_HOME, the folders are there instead. Files and environment lists everything cornercase writes. Git worktrees it created stay in ~/.cornercase/worktrees until you remove them with git worktree remove.