DEMONSTRATION: developer Udi Wertheimer has shown Half-Life: Alyx running directly on Apple Vision Pro, with no gaming PC and no streaming. The experiment combines Valve's ARM port of the game, made for the Steam Frame headset, with the open-source Klepton project and AI-assisted patching. It is not an official release from Apple or Valve, nor a product for sale: it is a technical demonstration, with code and a guide still promised by its author.
How the Half-Life: Alyx experiment works
The foundation is Valve's ARM port of Half-Life: Alyx prepared for Steam Frame, its standalone headset. Because Vision Pro also uses an ARM-family processor, that port gave the experiment a native starting point. On top of it, Wertheimer used Klepton, Max Thomas's project that rewrites Android libraries into Apple's format and translates graphics through ANGLE and MoltenVK. Since Valve's port runs on Linux rather than Android, the developer says the Claude AI filled in the remaining gaps and helped with optimization — his description, not a publicly documented architecture.
Reported performance — and what has not been proven
The disclosed figures differ between reports and should be read with caution. Spatial Insider records roughly 3K per eye at 60 frames per second, smoothed to 120 Hz, on a Vision Pro with the M5 chip. The Snazzy Labs video, meanwhile, mentions 45 frames per second reprojected to 90 Hz on an M2 model with PS VR2 controllers. No frame-time data, scene list or settings have been independently published so far, and Windows Forum notes that Klepton's public list includes Half-Life, Half-Life 2 and Portal — but not Half-Life: Alyx. In short: the video shows the game opening and running on the headset, but it does not prove stable performance or broad compatibility.
Why the experiment matters
The case shows two ongoing shifts. First, Valve already did the heavy lifting by adapting Alyx to standalone ARM hardware, which narrows the gap between platforms. Second, compatibility tools like Klepton are turning Vision Pro — criticized for its limited game library — into a device able to run titles from other ecosystems; the parallel AVP Play project, built on a Klepton fork, already lists the Quest catalog for rebuilding on visionOS. For readers, the right interpretation is that of an ingenious shortcut, not official support: nothing indicates that Apple or Valve endorse or distribute this adaptation.
Limits and next steps
The demonstration ran on the Vision Pro with the M5 chip, launched in 2025, and there is no evidence it runs comparably on the original 2024 M2 model. It also requires a paid Apple developer account for sideloading via Xcode, and it is not a one-click process. Wertheimer plans to publish a guide and the tools on GitHub so other headset owners can try to reproduce the feat with help from their own AI agents. Until then, the experiment is valuable for what it demonstrates — that the barrier between VR ecosystems is getting thinner — not for what it promises.
Also on Geekiki: Steam Frame CD-ROM: Valve adds kernel support in under 10 minutes after a player request.
Fontes: Spatial Insider — Half-Life Alyx Runs on Vision Pro Without a Gaming PC; Virtual Reality News — How to Play Meta Quest Games on Apple Vision Pro; Windows Forum — Half-Life: Alyx Reportedly Runs Natively on Apple Vision Pro; Klepton no GitHub; Snazzy Labs — Apple Should Be Embarrassed (vídeo).
Image credit: Half-Life: Alyx capture from Udi Wertheimer's Apple Vision Pro demonstration, image by Udi Wertheimer / Valve reproduced by Spatial Insider.
Transparency: this article was prepared with the help of artificial intelligence, based on cross-checking public sources on the internet and public posts on X. The performance figures cited are reports from the developer and from outlets that covered the demonstration, with no independently published data. Readers are advised to consult the original sources to confirm the details before any technical decision.
Muse
