Installation

All supported frontends are enabled by default. The editor is a standalone executable; editing, HLS, Git and conversations do not require the THC compiler or runtime.

Build the editor

You need GHC 9.6 or newer, Cabal, pkg-config and the development files for utf8proc 2.10 or newer, SDL3 3.2 or newer, and libghostty-vt. Set up Ghostty using the embedded terminal instructions below before building, or omit it with -f-terminal. On macOS:

brew install utf8proc sdl3

On Debian/Ubuntu, the package is libutf8proc-dev; check that your distribution supplies the required version. Then clone the main branch and build:

git clone --branch main https://github.com/ekmett/hide.git
cd hide
cabal build all
cabal run hide -- .

The default build includes terminal, native-window and browser displays. Without a display option, the editor runs in a UTF-8 terminal. An 80-column, 25-row terminal is a useful starting size. Mouse support, modified keys and exact colors follow the terminal's capabilities.

To install on your path, including the th and thc edit launchers:

make install

make install puts hide, th and thc-edit in ~/.local/bin (override BINDIR to choose another location). The small launchers find hide beside themselves and forward every argument. With THC installed, its external-command dispatch makes thc edit work. hide itself does not require THC. For a binary-only install, use cabal install exe:hide; copy the launchers from bin/ beside it if wanted. Windows uses th.cmd and thc-edit.cmd beside hide.exe.

Add that directory to PATH if it is not already there. All examples using hide also work from a checkout as cabal run hide -- ..., with the appropriate build flags before hide.

Native window

Native windows are enabled by default. Install SDL3 3.2 or newer. On macOS:

brew install sdl3
cabal run hide -- --window .

--window chooses Metal on macOS and Vulkan elsewhere. --metal and --vulkan select them explicitly. Linux window builds also need Pango/Cairo development headers (libpango1.0-dev on Debian/Ubuntu). fonts-noto-color-emoji supplies color emoji where a fallback font is needed. macOS uses CoreText.

An installed build includes this frontend too:

cabal install exe:hide --installdir="$HOME/.local/bin"

Browser

The browser frontend is enabled by default:

cabal run hide -- --web .

It opens a WebGL page served by the editor on an ephemeral loopback port. Keep the frontend process running while using the page. The editor session runs separately, so you can detach and resume it later. Set THC_EDIT_WEB_OPEN=0 to print the URL without opening a browser automatically.

Optional tools

Build flags are opt-out: -f-window omits SDL/native windows, -f-web omits the browser server, and -f-terminal omits Ghostty/embedded terminals. For a minimal terminal-display or remote-server build:

cabal build all -f-window -f-web -f-terminal

This still includes sessions, SSH editing, HLS, Git and conversations. A browser-only build can use -f-window -f-terminal, avoiding both native libraries.

Matching Haskell debugger

When a selected GHC has no available hdb adapter, the editor can offer a matching official hdb binary. Accept the concrete download offer to fetch it in the background. The Downloads window shows progress, failures and cancellation; declining downloads nothing. There is no automatic build from source.

The current catalog contains hdb 0.14.0.0 for GHC 9.14.1, on macOS Intel/Apple Silicon and the published Linux distributions. Other exact GHC versions, unlisted platforms and Windows currently require a separately installed adapter. The editor verifies the pinned SHA256 and retains the upstream wrapper, which checks the selected GHC's version and boot-library ABI before reporting ready. A matching version number alone does not guarantee ABI compatibility.

Tools share THC's CBD storage root: an absolute THC_CACHE_HOME override, ~/Library/Caches/thc on macOS, or the platform XDG cache directory's thc subdirectory elsewhere. Versioned launchers live in bin/hdb-9.14.1; complete bundles live under tools/hdb/<release>/<platform>/. Existing unmanaged launchers are never overwritten. These tools can be downloaded again if the cache is cleared. Acquisition needs curl, tar, and shasum on macOS or sha256sum on Linux; it does not change shell startup files or PATH.

Bundled Ghostty discovery

On macOS and Linux, the checked-in cabal.project selects a small pkg-config wrapper that searches .deps/ghostty/share/pkgconfig and .deps/ghostty/lib/pkgconfig before the inherited search path. Installing Ghostty under this checkout's .deps/ghostty therefore lets ordinary cabal build work from the editor or a fresh shell without exporting PKG_CONFIG_PATH. Run Cabal from the checkout root: the extra program path is relative to the invocation directory. Other dependencies still use the system pkg-config paths. This discovers an existing installation; it does not download or build Ghostty.

cabal.project.local is the ignored file for machine-specific Cabal overrides. Native Windows uses its normal pkg-config.exe; it skips the POSIX wrapper. A Ghostty installation elsewhere, including the Windows setup below, still needs its pkg-config directory on PKG_CONFIG_PATH.

Embedded terminal

Embedded terminals enable File > Terminal, Run > Run and ACP terminal requests through libghostty-vt. They are enabled by default and work independently of SDL. macOS and Linux use a PTY; native Windows uses ConPTY (Windows 10 version 1809 or newer). On Windows the default shell is COMSPEC, usually cmd.exe; terminal commands run in the editor session’s project directory.

The Ghostty C API is evolving. The verified source revision is 76895d97b74ff6b24c2b1543bcd69ccc18048a4d, built with Zig 0.16.0:

git clone https://github.com/ghostty-org/ghostty /tmp/thc-ghostty
cd /tmp/thc-ghostty
git checkout 76895d97b74ff6b24c2b1543bcd69ccc18048a4d
zig build -Demit-lib-vt=true -Demit-xcframework=false -Doptimize=ReleaseFast --prefix /tmp/thc-ghostty-install
cd /path/to/hide
export PKG_CONFIG_PATH=/tmp/thc-ghostty-install/share/pkgconfig:$PKG_CONFIG_PATH
cabal run --ghc-options=-optl-Wl,-rpath,/tmp/thc-ghostty-install/lib hide -- --window .

For a native Windows remote server, build the same pinned Ghostty checkout in PowerShell, then expose its package metadata and DLL:

$ghosttyPrefix = "$env:LOCALAPPDATA\hide\ghostty"
zig build -Demit-lib-vt=true -Demit-xcframework=false -Doptimize=ReleaseFast --prefix $ghosttyPrefix -j4
$env:PKG_CONFIG_PATH = "$ghosttyPrefix\share\pkgconfig;$env:PKG_CONFIG_PATH"
$env:PATH = "$ghosttyPrefix\bin;$env:PATH"
cd C:\path\to\hide
cabal build all -f-window -f-web

Keep utf8proc's package metadata and DLL on those paths too. This includes embedded terminals on the remote server; the native-window and browser clients can run on another machine. The pinned Ghostty library builds in ReleaseFast; its upstream test-lib-vt checks should use -Doptimize=Debug.

Keep the installed Ghostty library available at runtime, or use your system's normal library installation path. A build with -f-terminal can still edit, use HLS, review Git changes and hold conversations.

Bash completion

With current thc and the installed thc-edit launcher on your PATH, enable Bash completion with:

source <(thc --bash-completion-script)

This completes thc edit options and file paths, including names with spaces. Add the command to your Bash startup file to enable it in future shells.

Defaults

Environment variables override [editor.defaults] in the shared configuration file. Explicit frontend, scale and appearance options override both. For example, hide --terminal . overrides a configured graphical frontend. hide --help lists the command-line options. Display and frontends covers screen modes and interactive preferences.

Provider and Run target settings remain in the user's legacy thc-edit configuration directory, normally $XDG_CONFIG_HOME/thc-edit or ~/.config/thc-edit on Unix. Appearance and key preferences can be changed for the running editor under Options > Preferences. Shared startup defaults and Agent Permissions live separately in thc/config.toml; use that file for repeatable launches across projects.

The rename preserves existing settings and resumable sessions in their thc-edit storage directories. The THC_EDIT_* environment variables and shared thc/config.toml / project thc.toml settings also retain their names; none of these require a THC installation.