Remote Desktop: Wayland compatibility problems and macOS screen capture not implemented

Wayland — Known Issues

1. Screen capture requires session user UID (blocks root deployments)

KWin (KDE Plasma 6) and most other Wayland compositors restrict zwlr_screencopy_manager_v1 to processes whose UID matches the session user. When the agent runs as root, the compositor simply does not advertise the protocol, making screen capture impossible.

Affected compositors: KWin (KDE Plasma 6), likely others
Not affected: sway, hyprland, labwc, river (these advertise screencopy to all clients)
Current behaviour: the pseudo-RD service is not advertised when screencopy negotiation fails, so the failure is silent rather than broken — but remote desktop is unavailable.

Potential solutions (in order of preference):

• Run the agent as the session user and grant network capabilities via setcap cap_net_raw,cap_net_admin+eip — requires removing the hard is_root() exit check and adding the session user to the input group for uinput access
• Spawn a small privileged-drop helper binary that runs as the session user, connects to Wayland, and streams frames back over a Unix socket
• Implement xdg-desktop-portal + PipeWire screen capture — compositor-agnostic but shows a one-time user-approval dialog that cannot be displayed in the browser UI; requires the user to be physically present at the machine for first-run approval

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2. GNOME / Mutter: zwlr_screencopy_manager_v1 not implemented

GNOME's compositor (Mutter) does not implement the wlr-screencopy protocol at all. Remote desktop is therefore unavailable on any GNOME Wayland session regardless of which user the agent runs as.

Affected sessions: GNOME on Wayland (Ubuntu 22.04+, Fedora Workstation, etc.)
Potential solution: xdg-desktop-portal + PipeWire (org.freedesktop.portal.ScreenCast) — this is the only screencopy path Mutter supports, but it has the first-run dialog problem described above.

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3. Clipboard sync unavailable on pure Wayland

copypasta's ClipboardContext attempts an XCB/X11 handshake regardless of the active display protocol. On a pure Wayland session without XWayland, this always fails.

Current behaviour: clipboard initialisation failure is caught and clipboard sync is disabled for the session (graceful degradation). Remote desktop still opens; only clipboard paste/copy is non-functional.
Potential solution: add Wayland clipboard support via wl-clipboard or switch to the arboard crate which has native Wayland support.

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4. Input injection (/dev/uinput) requires group membership

/dev/uinput is owned by root and the input group. When the agent is moved to run as the session user (the fix for issue 1), the user must be a member of the input group for uinput-based input injection to work.

Current behaviour: works when running as root; breaks if moved to session user without group setup.
Required: add the session user to the input group, or document this as a post-install step.

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macOS — Not Implemented + Anticipated Issues

5. Screen capture not implemented

macOS falls through to the "Screen capture is not supported on this platform" error path. No capturer exists for Quartz/CoreGraphics.

Required implementation: CGDisplayCreateImage() (CoreGraphics, via the core-graphics crate) or ScreenCaptureKit (macOS 12.3+, stricter but modern).

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6. Screen capture will require session context + TCC permission (same root problem, different mechanism)

Even once implemented, a root launchd daemon will face two separate blocks:

• WindowServer session access — the WindowServer is owned by the GUI login session. A daemon launched outside that session cannot connect to it regardless of UID.
• TCC Screen Recording permission — since macOS 10.15, all screen capture requires explicit user approval in System Settings → Privacy & Security → Screen Recording. Enforced by the TCC daemon against the binary's code-signing identity; root UID does not bypass it.

Consequence: the same architectural problem as Wayland — the agent must either run as a login item in the user's GUI session, or use a session-context helper process. Running as root is insufficient.

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Summary

Platform	Screen capture	Input injection	Clipboard
Linux / X11 (agent as root)	✅ works	✅ works	✅ works
Linux / Wayland, KDE/KWin (agent as root)	❌ UID restriction	✅ uinput works	❌ X11 only
Linux / Wayland, GNOME (agent as root)	❌ protocol missing	✅ uinput works	❌ X11 only
Linux / Wayland (agent as session user)	✅ works (KDE/sway/hyprland)	⚠️ needs input group	❌ X11 only
macOS	❌ not implemented	❓ not tested	❓ not tested
Windows	✅ GDI works	✅ works	✅ works