kwin-portal-bridge

A Rust bridge that lets Anthropic's computer-use tooling actually work on KDE Plasma 6.6+ under Wayland. Paired with a fork of claude-desktop-bin, this gets you near feature parity with the Windows and macOS computer-use experience — clicks, keystrokes, screenshots, window management, the whole dance — without X11 fallbacks and without pretending Wayland doesn't exist.

Status: experimental

This is a from-scratch reimplementation of the platform glue that Claude's computer-use executor normally relies on. It talks to Plasma through KWin scripts and the XDG desktop portal (RemoteDesktop + ScreenCast via PipeWire).

Things to keep in mind before pointing it at anything important:

• Policy enforcement is looser than upstream. The stock Windows/macOS executors enforce a number of safety and allowlist policies at points this bridge can't always observe. Most of them are reimplemented here, but some are approximated and a few aren't enforced at all. If you depend on upstream's exact guarantees, don't assume they hold here.
• The standalone MCP mode (kwin-portal-bridge mcp) is a proof of concept. It exposes the bridge directly over stdio MCP without the desktop host wrapping it. It is missing a lot of features that the full executor integration has, and it performs no security checks at all — no allowlisting, no prompts, no hidden-window enforcement. Treat it as a toy for local experimentation. Do not point an untrusted model at it.

What it does (the bragging part)

• Real Wayland input via the RemoteDesktop portal. Pointer move, click (with modifiers), drag, scroll, keyboard press/release, sustained key holds, and executor-style key sequences like ctrl+shift+t.
• Real typing, not synthetic key chords — text is sent as keysyms with configurable per-character delay, so IMEs and autocomplete behave sensibly.
• Screenshots and region zoom through the ScreenCast portal and PipeWire.
• KWin-native window introspection: enumerate screens and windows, query the frontmost app, find the topmost app under a point, set geometry, toggle keep-above, activate windows.
• excludeFromCapture enforcement. Before a screenshot or action, disallowed apps are hidden from capture via a prepare-for-action transaction and restored immediately after, so partial failures don't leak other windows' contents.
• Long-lived portal session daemon. One portal consent prompt per tool-use lock instead of one per action. The session is held open by a background daemon and torn down cleanly on exit.
• Clipboard integration via wl-clipboard-rs, gated on the session lock.
• Desktop application integration: enumerate installed .desktop entries, resolve icons to data URLs, launch apps by bundle id / desktop id / name / path (via kioclient for proper KDE activation).
• Teach overlays. An iced + layer-shell overlay for manual teaching bubbles, plus a session-edge overlay that indicates an active computer-use session without obscuring content.
• Standalone MCP server mode for wiring the bridge directly into any MCP-capable client (see caveats above).

Requirements

• KDE Plasma 6.6 or newer, running on Wayland.
• xdg-desktop-portal-kde with RemoteDesktop and ScreenCast support.
• PipeWire.
• A Rust toolchain matching edition = "2024" (recent stable).

Build

cargo build --release

The binary lands at target/release/kwin-portal-bridge.

Usage

The full executor integration expects this binary to be invoked by a fork of claude-desktop-bin that routes computer-use calls to it. That's the supported path.

For quick local tinkering:

kwin-portal-bridge screens         # enumerate displays
kwin-portal-bridge windows         # enumerate windows
kwin-portal-bridge screenshot      # capture the current screen
kwin-portal-bridge mcp             # run as a standalone MCP server (PoC!)

kwin-portal-bridge --help lists every subcommand.

License

TBD.