avalonia
Avalonia UI
Overview
Avalonia is a cross-platform .NET UI framework using XAML (.axaml), with its own Skia-based rendering engine, supporting Windows, macOS, Linux, iOS, Android, and WASM.
Supported versions: 11.3 (legacy), 12.0, 12.1 (current stable, 12.1.4). Default for new projects: latest 12.1.x on net10.0.
Rule 1 — version first: Before writing or reviewing code, detect the project's Avalonia version (Avalonia PackageReference in *.csproj / Directory.Packages.props). Many APIs differ between 11.x and 12.x (clipboard, drag-drop, Android lifetime, Watermark, window decorations, compiled-binding default). Load avalonia-versions when unsure whether a feature exists in that version, or when migrating/upgrading.
Rule 2: Always load the matching subskill before writing or reviewing Avalonia code. Subskills mark version-specific content as (12.0+), (12.1+) or (11.x); unlabelled content works in all supported versions.
Rule 3 — documentation lookup: Prefer available MCP documentation tools before browsing: use an Avalonia-specific documentation provider first, then a general library-documentation provider such as Context7. Identify suitable tools by their descriptions and capabilities, not a fixed server alias. Follow the official documentation links when suitable MCP tools are unavailable or their results are incomplete, unrelated, or do not establish the target version. Verify version-specific behavior against matching documentation, tagged source, and the project's Avalonia packages. MCP providers are optional; keep the official links as sources and fallback.
Bundled references: Resolve each route relative to this skill's directory: avalonia-xaml means avalonia-xaml/SKILL.md, and avalonia-pro-max/motion means avalonia-pro-max/motion/SKILL.md. Read the matching file even when the host exposes only the avalonia entrypoint. Resolve that file's supporting links and scripts relative to its own directory.