DeeJanuz--frametop/AGENTS.md

Working on Frametop

Rules for people and coding agents changing this repo. The README covers what Frametop is and how to install it; docs/reference.md covers each component, and docs/design.md records how SteamVR on the Frame behaves and why things are built the way they are. Read its notes on SteamVR before changing how the screens, the pointer, or the input relay talk to SteamVR.

Two ways to run the scripts

Every script works in both modes, and must keep working in both:

• On the Frame (SteamOS, VR variant), commands run locally, in this checkout.
• From a PC over SSH, the repo is synced to ~/dev/frametop on the Frame (scripts/sync.sh), and commands run there. scripts/_env.sh works out which mode applies (FRAME_LOCAL, FRAME_HOST, FRAME_REPO).

scripts/sync.sh                          # PC -> ~/dev/frametop on the Frame
scripts/frame.sh -C <dir> '<build cmd>'  # runs in the "dev" Fedora distrobox
scripts/frame.sh --host '<cmd>'          # runs on the SteamOS host

• From a PC, edit only on the PC. The Frame's copy is a mirror that sync.sh overwrites.
• Build inside the dev container. The SteamOS host has a read-only root and no compilers. Container builds link against the container's libraries, so they run in the container (distrobox enter dev -- ...); the SteamVR driver is built to run on the host.
• Container packages the build needs go in the list in setup/dev-container.sh, so the container can be rebuilt.
• Build output goes in build/ next to the sources. It's gitignored and never synced.

The headset may be in use

A Steam Frame is someone's personal headset, and they may be wearing it while you work.

• Don't kill or restart gamescope, steam, vrserver, vrcompositor, the gamescope session, or the Frametop desktop without asking. Each one ends or disrupts whatever is happening in VR.
• Don't run host sudo, steamos-readonly disable, steamos-devmode changes, pacman installs, or reboots without explicit approval. Three installers need host sudo, and they ask for it: the Bluetooth fixes (setup/bluetooth/install.sh), hand tracking (hands/run.sh install and caps, which set ft-camd's file capabilities with setcap), and our own eye tracker's frame grabber (gaze/tracker/install.sh).
• Write only inside the repo, /tmp, and the container unless told otherwise. The installers are the exception: they write the user services, launchers, and the SteamVR driver into the home folder. The Bluetooth fixes and the eye tracker's frame grabber also install root-owned files and system services under /etc (/etc/steamframe, /etc/frametop, /etc/systemd/system).
• Never copy .netrc, SSH keys, or Steam config off the Frame or into this repo.

SteamOS updates

A SteamOS update replaces SteamVR, KWin, and gamescope with the rest of the OS image. When a change starts depending on something from the image (a host file, an OpenVR interface outside the bundled header, an undocumented layout or output format, a SteamVR or KWin quirk), add a check for it to scripts/update-check.py, or a retest hint for its package there. docs/design.md has the background.

Names

User-facing names are "Frametop", "Frametop Display Settings", and "Frametop Input Settings". Programs and files use the ft- / ft_ prefix (ft-screens, ft-pointer, ft-layout, the ft_pointer driver); config, units, and overlay keys use frametop. Program names must stay within 15 characters: Linux truncates process names there, and the scripts find programs with pgrep -x / pkill -x.