WebUI

WebUI is a high-performance, language-agnostic server-side rendering framework built in Rust. It compiles HTML templates into compact Protocol Buffer binaries at build time so runtime rendering applies state without reparsing templates. Interactive Web Components hydrate as islands on the client.

Documentation: microsoft.github.io/webui

Highlights

• Compiled templates: HTML is parsed once at build time into a compact binary protocol.
• Language agnostic: Rust, Node/Bun/Deno, C#, Python, Go, and any language that can call C FFI.
• Web Components: Native custom elements with Shadow DOM support.
• Server-side logic: Conditions, loops, and expressions are evaluated on the server.
• Plugin-ready: Parser and handler plugins support framework-specific hydration and directives.

Install

npm install @microsoft/webui

Or install the Rust CLI:

cargo install microsoft-webui-cli

For .NET server-side bindings:

dotnet add package Microsoft.WebUI

The NuGet package restores platform-specific Microsoft.WebUI.Runtime.* native assets transitively. Release builds stage .nupkg and .snupkg artifacts with repository metadata and Source Link; nuget.org publishing is manual until ESRP automation supports this project. NuGet metadata uses Authors=Microsoft, the Microsoft package owner, a stable project URL, a package license URL with license acceptance required, release notes links, discoverability tags, and the required © Microsoft Corporation. All rights reserved. copyright notice. Before nuget.org publishing, staged packages and Authenticode-signable contents must be signed with a Microsoft certificate through the approved signing process.

Learn

Resource	Link
Full documentation	https://microsoft.github.io/webui
Getting started	https://microsoft.github.io/webui/guide/
CLI reference	https://microsoft.github.io/webui/guide/cli/
Language integrations	https://microsoft.github.io/webui/guide/integrations
Benchmarks	BENCHMARKS.md

Development

Prerequisites:

• Rust 1.93+ with clippy and rustfmt
• Node.js 22+ with pnpm

Common commands:

Command	Description
cargo xtask check	Run the full repository quality gate before commits
cargo xtask fmt	Check formatting
cargo xtask clippy	Run clippy lints
cargo xtask test	Run all tests
cargo xtask build	Build the workspace and examples
cargo xtask dev <app>	Run an example app in development mode
cargo xtask bench <target>	Run benchmarks
cargo xtask build-windows-local	Manually build and stage Windows MSVC artifacts on macOS

Manual Windows builds on macOS

cargo xtask build-windows-local is a local-only helper for producing Windows x64 and ARM64 release bits from macOS. It does not run in CI and does not install tools automatically.

Install the build prerequisites once:

brew install llvm lld
cargo install cargo-xwin --version 0.23.0
rustup target add x86_64-pc-windows-msvc aarch64-pc-windows-msvc

If Homebrew's clang-cl and LLD are not on PATH, add them before running the helper:

export PATH="$(brew --prefix llvm)/bin:$(brew --prefix lld)/bin:$PATH"

Build both Windows targets, or choose one target:

cargo xtask build-windows-local
cargo xtask build-windows-local --target x64
cargo xtask build-windows-local --target arm64

The command stages artifacts into publish/native/, packages/webui-win32-*, and dotnet/runtimes/win-*/native/. cargo-xwin downloads Microsoft Windows SDK and CRT assets; using it requires accepting the Microsoft SDK license terms referenced by cargo-xwin.

For a quick local sanity check of the x64 CLI artifact, install Wine Stable:

brew install --cask wine-stable

Wine Stable may require explicit approval in macOS System Settings > Privacy & Security because it is not notarized. After approving it, run:

WINEDEBUG=-all WINEPREFIX="$PWD/.wine-webui-x64" \
  "/Applications/Wine Stable.app/Contents/Resources/wine/bin/wine" \
  "$PWD/packages/webui-win32-x64/bin/webui.exe" --help

Use Wine only for the x64 artifact. Test the ARM64 Windows artifact on Windows ARM hardware or a Windows ARM environment.

For contribution policy, issue guidelines, and the current pull request policy, see CONTRIBUTING.md.

Project layout

crates/      Rust crates for the CLI, parser, handler, protocol, FFI, and integrations
packages/    npm packages for the CLI, WebUI Framework, router, and platform binaries
dotnet/      .NET bindings, runtime packages, and global tool packaging
docs/        VitePress documentation site
examples/    Example applications and integration samples

Feedback and support

WebUI is still in active development. We are not accepting unsolicited pull requests right now, but we do welcome well-documented issues:

Need	Where to go
Report a bug	Choose an issue template
Request a feature	Choose an issue template
Report a documentation need	Choose an issue template
Get support guidance	SUPPORT.md
Report a security issue	SECURITY.md

This project has adopted the Microsoft Open Source Code of Conduct.

Trademarks

This project may contain trademarks or logos for projects, products, or services. Authorized use of Microsoft trademarks or logos is subject to Microsoft's Trademark & Brand Guidelines. Use of Microsoft trademarks or logos in modified versions of this project must not cause confusion or imply Microsoft sponsorship. Any use of third-party trademarks or logos is subject to those third party policies.

License

MIT