# Open a KDE Kirigami window with bun:ffi

KDE applications are Qt applications, and Kirigami (part of KDE Frameworks 6) is a QML module. As with [Qt](https://bun.aphrody.com/docs/guides/runtime/qt-window), `bun:ffi` loads a small `extern "C"` shim: it creates a `QQmlApplicationEngine`, loads a `Kirigami.ApplicationWindow` and runs `QApplication::exec()`.

```cpp shim.cpp icon="file-code"
#include <QApplication>
#include <QQmlApplicationEngine>
#include <QVariantMap>

static const char qml[] = R"(
import QtQuick
import QtQuick.Controls as Controls
import org.kde.kirigami as Kirigami

Kirigami.ApplicationWindow {
    pageStack.initialPage: Kirigami.Page {
        title: "Kirigami through bun:ffi"
        Controls.Label { text: "Hello from Bun" }
    }
}
)";

extern "C" int bun_kirigami_window_run(const char* title, int width, int height) {
    static int argc = 1;
    static char arg0[] = "bun";
    static char* argv[] = {arg0, nullptr};
    QApplication app(argc, argv);
    QQmlApplicationEngine engine;
    engine.setInitialProperties({
        {"title", QString::fromUtf8(title)}, {"width", width}, {"height", height}, {"visible", true},
    });
    // A qrc: URL keeps loading synchronous, so rootObjects() is ready right away.
    engine.loadData(qml, QUrl(QStringLiteral("qrc:/window.qml")));
    if (engine.rootObjects().isEmpty())
        return -1;
    return app.exec();
}
```

```sh terminal icon="terminal"
c++ -std=c++20 -shared -fPIC -o libshim.so shim.cpp $(pkg-config --cflags --libs Qt6Widgets Qt6Quick Qt6Qml)
```

```ts window.ts icon="/icons/typescript.svg"
import { dlopen, FFIType } from "bun:ffi";

const { symbols } = dlopen("./libshim.so", {
  bun_kirigami_window_run: { args: [FFIType.ptr, FFIType.i32, FFIType.i32], returns: FFIType.i32 },
});
process.exit(symbols.bun_kirigami_window_run(Buffer.from("Hello from Bun\0"), 640, 400));
```

```sh terminal icon="terminal"
bun window.ts
```

Kirigami is a runtime dependency only: the shim links Qt Quick and Qt QML, and the engine imports `org.kde.kirigami` when it loads the QML. Install it with your distribution's `kirigami` package, or on Windows with [MSYS2](https://www.msys2.org) (`pacman -S mingw-w64-ucrt-x86_64-kirigami`, with `C:\msys64\ucrt64\bin` on `PATH`). Without a display, set `QT_QPA_PLATFORM=offscreen` and `QT_QUICK_BACKEND=software`.

## Tested platforms

The fixture prints `window created` and `window closed` with exit code 0 on:

- Windows 11: Kirigami 6.30.0 from MSYS2 UCRT64
- Ubuntu 26.04: Kirigami 6.24.0 under `xvfb-run`

The Linux images are `scripts/aphrody/gui/ubuntu.Dockerfile` and `scripts/aphrody/gui/alpine.Dockerfile`.

---

A fuller version with a `JSCallback` for window creation, an Escape shortcut, `--timeout`, and `--title`, `--width` and `--height` options lives in the Bun repository at [`test/js/bun/ffi/kde-window.fixture.ts`](https://github.com/aphrody-labs/bun/blob/main/test/js/bun/ffi/kde-window.fixture.ts).

See [Docs > Runtime > FFI](https://bun.aphrody.com/docs/runtime/ffi) for the full `bun:ffi` reference.