BAMA and REA: rebuild Mac apps with Claude

At a glance

What the video doesn't say

• ArtCraft has nothing to do with REA. They are two separate projects. ArtCraft didn't "copy" its apps, it wrote them from scratch as a clean-room rebuild: its own code, built from public specifications and observation. That is a big difference, legally too.
• "Free" is only half true. REA and BAMA cost nothing. The agent that runs them does: Claude Code only works with a paid Claude plan or via the API. And BAMA's clone step needs Computer Use for native Mac apps, which means Claude Pro or Max.
• BAMA is brand new. The repo went online on 24 October 2026, so it is one week old (as of 31 October 2026). Expect bugs and frequent updates.
• BAMA needs macOS 26. Plus Xcode 26 for the Swift 6.2 compiler. You never have to open Xcode, but it has to be installed.
• The build plans are not cloned third-party apps. Dave Ebbelaar took the 12 specs apart from his own menu bar app "Onyx". They describe what an app should do, not what someone else's app looks like.
• REA's star count is unusual. 414,956 stars in a little over six months, but only about 1,600 watchers. Nobody outside GitHub can check whether every star is real. The number is the one GitHub shows.

The links

Install REA

You need Node.js 22 (or newer) and npm. Then in the terminal:

npx rea-agents setup

Pick your agents (Claude Code, Codex, Cursor, Gemini CLI …), review the proposed changes and approve them. Then restart your agent. To analyze native programs, REA also needs an analysis tool such as Ghidra (free), Hopper or IDA. JavaScript and Electron apps work without one.

Install BAMA in Claude Code

/plugin marketplace add daveebbelaar/bama
/plugin install bama@bama

Then type /bama: the router looks at your project and picks the next skill. For the clone step, turn on Computer Use: in Claude Code via /mcp → computer-use → Enable, in the Claude desktop app in Settings.

Build a plan

1. Copy a spec from the specs/ folder of the BAMA repo into an empty folder, for example window-snapper.md.
2. Start Claude Code in that folder.
3. Send this sentence:

Build the app in window-snapper.md with BAMA.

BAMA and REA compared

BAMA's 12 build plans

What it really costs

A tip against surprises: start with the smallest plan (Window Snapper). BAMA calls each spec "an afternoon of agent time". That takes a noticeable bite out of your usage limit.

Prompts to copy

Rebuild your own app as a native Mac app (BAMA):

Clone my own web app [URL] as a native Mac app with BAMA. Screenshot every screen, write the user stories and build milestone 1.

Understand first, then build (REA):

Use REA to find out how [feature] works in [an app I own or am allowed to analyze]. Show me the evidence and explain it in plain words.

A feature for your own project:

I like how [app] handles [feature]. Describe the behaviour only from using it, without taking over the app's code, texts, icons or design, and turn it into user stories for my own app [name].

An app from an idea instead of a template:

/bama I want a small menu bar app that [task]. Write an app brief first, then the stories in milestones.

Adapt a build plan:

Read window-snapper.md. Change the name to [name], the shortcuts to [shortcuts] and cut everything that isn't needed for version 1. Then build it with BAMA.

Who gains what

What you can make of it

• A service: build small native Mac tools for teams with one specific problem (menu bar helpers, internal tools).
• Content: a series "I build a Mac app in one afternoon", one build plan per episode.
• Your own spec: write your app idea in BAMA's format (brief, how it works, stories, gotchas). That makes any idea buildable.
• Learning: let REA explain how your own or an open app solves a problem before you build it yourself.

Limits and risks

• Law: by its own note, REA is only for lawful research, education, interoperability, preservation and software you own or are authorized to examine. Many licence agreements (EULAs) forbid reverse engineering. Read them first.
• Brands and design: names, logos, icons, texts and the exact look of other apps are protected. Rebuilding a function with your own design is not the same as a copy. You alone are responsible for the rights.
• Privacy: while cloning, the agent sees everything in the app. BAMA recommends a demo account with sample data.
• Security: you install other people's code and give Computer Use access to your screen. Only install from the official sources; REA itself warns about copies with similar names.
• Maturity: BAMA is one week old. Not every build works the first time, and updates come often.

Your first hour

• Check: is your Mac on macOS 26? Install Xcode 26 from the App Store.
• Install BAMA in Claude Code (the two commands above).
• Copy the Window Snapper spec into an empty folder.
• Send the sentence "Build the app in window-snapper.md with BAMA." and let it build milestone 1.
• Start the finished app from the Dock and test it.
• Optional: set up REA (command above) and try it on your own or an open app.

My tip

Don't start with "clone app X", start with your own idea as a spec. That is legally clean, and you learn how BAMA thinks: brief, stories, one commit per story. Once that clicks, you build tools in one afternoon that you would otherwise pay for every month.

All links, commands and numbers checked on 31 October 2026 on the official pages.

Up next: ArtCraft

Mentioned briefly in the video, in full in the next reel: the ArtCraft team builds open-source apps with AI agents as clean-room rebuilds, for example PhotoCraft as a rebuild of Photoshop, plus apps for photos, video editing, vector graphics and PDF. If you can't wait: getartcraft.com.