BEER (Bottled Executable Environment Runner)

An experimental native macOS app that turns your Steam library into installable, per-game Wine bottles — with bidirectional Steam Cloud save sync so you can move between a Windows PC and your Mac.

Inspired by GameNative on Android, adapted to macOS where Wine prefixes ("bottles") fit better than Docker-style containers.

Apple Silicon (M1+) and macOS 14+. Not for Intel Macs.

What it does

• QR sign-in — log in by scanning a code with the Steam Mobile App. No password is ever typed into the app, and no Steam Web API key is needed.
• Library — lists your owned games (installed ones float to the top; there's a dedicated "Installed" tab).
• Install per game — downloads each game with DepotDownloader into its own Wine bottle, drops in the Goldberg/GBE Steamworks shim where needed, and runs it on Apple's Game Porting Toolkit (GPTK) Wine.
• Display handling — choose Standard mode for performance and compatibility, or High Resolution mode to expose Retina resolutions to games. Note: GPTK runs games borderless and owns the window itself, so there's no macOS title bar or green fullscreen button.
• Per-game launch arguments — add engine or compatibility flags from the installed game's page; arguments are passed directly to its executable.
• Cloud saves — saves sync both ways with Steam Cloud automatically (pull before play, push after). Every sync backs up local saves first, so nothing is overwritten without a recoverable copy.

This does not run the real Steam client and does not bypass DRM, anti-cheat, or platform restrictions. Games are downloaded individually and run in isolated per-game bottles.

Run (development)

swift run BEER

Build a distributable app

scripts/build_app.sh 0.3.1      # → .build/BEER.app + .build/BEER.zip

The script compiles the app, bundles the native CloudSync helper, ad-hoc signs, and zips it. The build isn't notarized, so a downloader must run once:

xattr -dr com.apple.quarantine /Applications/BEER.app

First run

The app installs DepotDownloader, walks you through QR sign-in, and downloads Apple's Game Porting Toolkit runtime (large) the first time you install a game.

More

• HANDOFF.md — architecture, debugging entry points, and known sharp edges.
• CONTRIBUTING.md — how to build, test, and submit a pull request.
• CONVENTIONS.md — coding conventions and what "done" means for a PR.
• GOVERNANCE.md — how changes land and the senior-maintainer path.
• CODE_OF_CONDUCT.md — expectations for everyone in the project's spaces.
• AGENTS.md / CLAUDE.md — repo conventions and guardrails for contributors and tooling.
• Tools/CloudSync/README.md — the SteamKit2 cloud helper.

Project status

This started with one goal: play Kingdom Come: Deliverance on a MacBook, seamlessly. That goal is met — the game runs well and saves sync.

It's still maintained, but updates will be infrequent and support is limited. It's worked on in spare time, not on a schedule — expect slow responses on issues and pull requests, and don't depend on it for anything critical.

How it's built

BEER began as an AI-generated prototype, just to get the game running. It has since become an experiment in steering AI coding tools within a consistent architecture: a documented layout (PROJECT_STRUCTURE.md), written rules for agents and contributors (AGENTS.md, CONVENTIONS.md), and an offline test suite that checks changes without a live Steam account. AI writes much of the code; a human directs the design and reviews it.

Maturity: treat the current code as a working prototype, not a polished foundation. It runs, but it still needs real hardening — refactoring, test coverage, and architectural cleanup.

Pull requests are welcome, and if you're an experienced developer who'd like to help steer or co-maintain it, open an issue to start the conversation. See CONTRIBUTING.md to get started.

Contributing

Contributions are welcome. Please read CONTRIBUTING.md first — the short version: Apple Silicon + macOS 14+ only, test only against your own Steam account, and never let anything touch saves without a backup.

Disclaimers

Please read these before using or distributing BEER. This is not legal advice.

• For games you own. BEER uses your own Steam account to download games you have purchased, via DepotDownloader. It is not a piracy tool and does not unlock, crack, or grant access to content you don't own. Don't use it to obtain or run software you haven't bought.
• Steam Subscriber Agreement / account risk. Downloading outside the official client, running games outside it, and applying the Goldberg/GBE Steamworks shim may violate Steam's terms of service and could put your Steam account at risk, up to suspension or ban. Use entirely at your own risk. Only ever sign in with your own account.
• Goldberg/GBE. BEER applies the Goldberg/GBE Steamworks emulator so games that call the Steamworks API can run without the official client. It emulates that API for games you own; it is not a means of bypassing purchase.
• Not affiliated. BEER is an independent project. It is not affiliated with, endorsed by, or sponsored by Valve, Steam, Apple, or the GameNative project. "Steam" and all other trademarks belong to their respective owners; names are used only to describe interoperability.
• No warranty. Provided "as is" under the MIT license, with no warranty of any kind. BEER manipulates game files and save data; despite automatic save backups, the authors are not liable for lost saves, data, or any action taken against your account.

If you are a rights holder with a concern about this repository, please open an issue, or use Security → Report a vulnerability on this repo for a private channel to the maintainer.

License

MIT, © Widukind Technologies LLC. DepotDownloader, Goldberg/GBE, and Apple's Game Porting Toolkit are fetched at runtime by the app and keep their own licenses — they are not redistributed in this repository.