Introduction
Note
This book was written entirely by Claude Opus 4.6 and will likely also be maintained in the future with the help of AI to ensure a consistent tone of voice, style, and quality.
All contents have been reviewed by humans but there might still be some mistakes left. That would put it in good company since the artisanal, hand-crafted spec.yaml, that contains the TOML config specification, contains plenty of mistakes as well.
The writing is of high quality in my estimation, certainly better than what I would have produced in any reasonable amount of time. There are few obvious slop indicators. The AI sometimes uses superlatives (“ideal”, “best”) that I would not use myself, but I’ve seen this style in other pieces of documentation, so maybe it is just a style that aims to be approachable or to guide users towards good solutions.
If you find something objectionable in this book, do not hesitate to open an issue.
Jay is a Wayland compositor for Linux with an i3-inspired tiling layout. It supports Vulkan and OpenGL rendering, multi-GPU setups, fractional scaling, variable refresh rate (VRR), tearing presentation, HDR, and screen sharing via xdg-desktop-portal. X11 applications are supported through Xwayland.
Jay is configured through a declarative TOML file, with an optional advanced
mode that uses a shared library for programmatic control. A built-in
control center (opened with alt-c) provides a full GUI
for inspecting and changing compositor settings at runtime – including output
arrangement, input devices, color management, GPU selection, and more. A
comprehensive command-line interface makes scripting and automation
straightforward.
See the Features chapter for a comprehensive overview of what Jay can do, or jump straight to Installation to get started.
License
Jay is free software licensed under the GNU General Public License v3.0.