Valve has open-sourced Lepton, its tool to bring Android games to Steam

Valve has open-sourced Lepton, a lightweight Android runtime Valve built to run VR Android games on its Steam Frame hardware. Lepton strips Android down to the bare minimum needed to launch into games, intentionally avoiding full Android functionality so it serves as a focused bridge for titles rather than a general-purpose OS layer. The code is available in Valve’s frame-public/lepton GitLab repository, and documentation describes the runtime’s intent and constraints.

Developers have already used Lepton to port Meta Quest games to the Steam Frame, demonstrating it can move existing VR Android titles onto Valve’s platform without a complete rewrite. Open-sourcing the tool lets other studios inspect, adapt, and contribute to that bridge, but its narrow design means ports will remain centered on launching and running VR games rather than enabling the broader Android app ecosystem. The practical takeaway is that Lepton makes Steam Frame a viable target for Android-origin VR games, while leaving more extensive Android integration or non-game use cases to separate projects.