What is Prefab?

Every project starts the same way: the same folders, the same starter files, the same few commands you run before you can begin. Prefab records that setup once and rebuilds it whenever you need it.

A template is a folder and everything inside it - subfolders, starter files and their contents, Finder tags, folder icons, and any setup that should run once the folder exists. Templates live in Prefab's library. Deploying one builds a real folder on disk, wherever you point it, named for the project you are starting.

The Prefab template editor: a folder tree on the canvas, with a settings panel on the right — Whatever the canvas shows is what lands on disk.

What it replaces

Prefab is for the setup you do by hand every time:

Duplicating last month's project folder and deleting the parts that don't apply
Copying a _TEMPLATE folder and renaming it
Retyping the client's name into six folders and two documents
A setup script that works, but that nobody else on the team will run

Nothing is copied from an old project, so nothing arrives that has to be cleaned out.

Placeholders, actions and watched folders

Three ideas do most of the work.

Placeholders are the parts you fill in later. Anywhere you would type the project's name, write {{project_name}} instead - in a folder name, a file name, or inside a file. Define it once in the template's Placeholders tab and Prefab asks you for the value as it deploys, then writes your answer everywhere the placeholder appears.

Actions are things a template does rather than contains: initialise a git repository, reveal the new folder in FinderFile Explorer, run a command. They run once, as the folder is created.

Watched folders carry on working after the folder exists. Drop a reference image in, and it can be renamed to your convention, converted, tagged and filed into a subfolder. This happens only while Prefab is running.

You don't have to start from nothing

If you already have a project laid out the way you like, drag it onto Prefab and it becomes a template. See Importing a folder.

Where to go next

Your first template

Build one, deploy it, and see the whole loop in about five minutes.

How Prefab thinks

Templates, placeholders, actions and watched folders, and how they fit together.

Import what you have

Turn an existing project folder into a reusable template.

Ways to deploy

Drag and drop, the menu barnotification area, FinderFile Explorer's right-click menu, or a link.

What you need to run it

Prefab needs macOS 14.6 or later.Prefab needs Windows 10 version 2004 or later. Three things depend on a newer system or on your permission:

Writing into a folder. Prefab is sandboxed, so macOS keeps it out of your folders until youPrefab writes where you point it, and asks rather than guessing. You point at one yourself. Choosing where to deploy counts as pointing at it, which is why most deploys never ask for anything. See Settings and permissions.
Folder icons are set through the system's own folder-icon mechanism on macOS 26 and later. On earlier versions Prefab composites the symbol onto the standard folder image instead, which looks close but is a picture rather than a live icon.
Terminal commands need a one-time permission before any of them will run. See Terminal commands.