F# bindings for WebUI — use any web browser as a GUI.

WebUI lets applications use a real web browser as the user interface while keeping the host program lightweight. This repository contains F# bindings and helpers that integrate WebUI with .NET applications.

WebUI repo: https://github.com/webui-dev/webui

• Portable (needs only a web browser at runtime)
• Lightweight (small library, low memory footprint)
• Fast binary communication protocol between host and frontend
• Multi-platform & multi-browser support
• Uses a private browser profile for safety
• Native runtime provided by WebUI (downloaded on first use or supplied manually)

dotnet add package FSharp.WebUI --version 2.5.3

• Linux x64 → webui-linux-gcc-x64.zip
• Linux ARM64 → webui-linux-gcc-arm64.zip
• Linux ARM → webui-linux-gcc-arm.zip
• macOS ARM64 → webui-macos-clang-arm64.zip
• macOS x64 → webui-macos-clang-x64.zip
• Windows x64 → webui-windows-msvc-x64.zip

dotnet build fsharp-webui.fsproj

dotnet run --project examples/simple-example
# or
dotnet build examples/simple-example/simple-example.fsproj
./examples/simple-example/bin/Debug/net10.0/simple-example 

dotnet run --project examples/prettier
# or
dotnet build examples/prettier/prettier.fsproj
./examples/prettier/bin/Debug/net10.0/prettier

dotnet run --project examples/reflection
# or
dotnet build examples/reflection/reflection.fsproj
./examples/reflection/bin/Debug/net10.0/reflection

Note: the examples use WebUI.Browser.Chromium by default in their sample code; change to another browser by passing a different Browser enum to WebUI.showBrowser if desired.

dotnet run --project tests/WebUITests
# or
dotnet build tests/WebUITests/WebUITests.fsproj
./tests/WebUITests/bin/Debug/net10.0/WebUITests

open WebUI

let html = """<!DOCTYPE html>
<html>
  <head>
    <script src="webui.js"></script>
  </head>
  <body>
    <button id="myBtn">Click Me</button>
  </body>
</html>"""

[<EntryPoint>]
let main argv =
    let myWindow = WebUI.newWindow()
    WebUI.bind myWindow "myBtn" (WebUIEventHandler(fun _ -> printfn "Clicked!"))
    WebUI.showBrowser myWindow html WebUI.Browser.Chromium |> ignore
    WebUI.wait()
    0

Native binaries are not redistributed in this package. They are downloaded from WebUI nightly releases on first use/build, verified with SHA-256, and cached per user machine.

Default release tag: nightly

• Windows: %LocalAppData%/fsharp-webui/nightly/<asset>
• Linux: ${XDG_CACHE_HOME:-~/.cache}/fsharp-webui/nightly/<asset>
• macOS: ~/Library/Caches/fsharp-webui/nightly/<asset>

• MSBuild refresh: WebUIBootstrapRefresh=true
• Environment refresh: WEBUI_BOOTSTRAP_REFRESH=true
• MSBuild native override: WebUINativePath=/path/to/native
• Environment native override: WEBUI_NATIVE_PATH=/path/to/native
• Optional tag override: WebUIReleaseTag / WEBUI_RELEASE_TAG (default remains nightly)

./scripts/smoke-bootstrap.sh

• SKIP_NETWORK_TEST=1 ./scripts/smoke-bootstrap.sh to skip the nightly download/verify test.

• Chrome
• Chromium
• Firefox
• Edge
• Safari
• AnyBrowser (automatic selection — let the native runtime pick the best available browser)

• .NET 10.0+
• A web browser (Chrome, Firefox, Edge, Safari, or Chromium)
• Network access to GitHub releases on first bootstrap (unless using native path override)

• WebUI repo: https://github.com/webui-dev/webui
• WebUI core documentation: https://webui.me/docs

Licensed under the MIT License.