Disclaimer: This project is not affiliated with or supported by Tailwind Labs.

Makes it possible to use "Just In Time" builds for Tailwind (Tailwind 3+) with ASP.NET Core.

Works for Blazor WASM applications that are hosted via ASP.NET Core, and Blazor Server applications.

Note this doesn't work with Blazor WASM apps that aren't hosted via ASP.NET Core.

The simplest way to integrate Tailwind during Development is to use the Tailwind CLI directly via this library's hosted service.

Simple path (recommended):

• Download the official Tailwind CSS standalone CLI for your OS and add it to your system PATH so the command tailwind is available, OR
• Download it and set the full path in configuration via Tailwind:TailwindCliPath.

There is no auto-download of the Tailwind CLI. The CLI must be present on PATH or referenced by a full path.

1. Install the NuGet package in your ASP.NET Core app:

 dotnet add package Tailwind.Extensions.AspNetCore

2. Configure Program.cs before Build():

using Tailwind;

var builder = WebApplication.CreateBuilder(args);

// other services...

// Enable Tailwind CLI watcher (Development only)
builder.UseTailwindCli();

var app = builder.Build();

3. Add configuration (appsettings.Development.json):

{
  "Tailwind": {
    "InputFile": "./Styles/input.css",
    "OutputFile": "./wwwroot/css/output.css",
    "TailwindCliPath": "" // optional: set full path if not on PATH
  }
}

Notes:

• If TailwindCliPath is empty, the service runs a command named tailwind from PATH.
• Secondary option (if you use npm-installed CLI): on Windows you can point to the npm shim, e.g. .\\node_modules\\.bin\\tailwind.cmd.
• The hosted service is a no-op outside Development and stops the CLI when the app stops.

4. Ensure Tailwind CLI is available:

• Preferred: use the standalone Tailwind CLI (downloaded binary) and add it to PATH or set TailwindCliPath.
• Alternative: install via npm in your project (npm install -D tailwindcss) and ensure the CLI is resolvable (PATH or TailwindCliPath).

5. Run your app: Run dotnet watch run. In Development, the service will run tailwind -i <input> -o <output> --watch and log the exact command.

See demos/net8 for a working setup (Program.cs calls builder.UseTailwindCli();, appsettings.Development.json contains the Tailwind section).

If you prefer to keep Tailwind as an npm script, you can use this extension to run your npm script during Development.

Create a new Hosted Blazor WASM, or Blazor Server project.

CD to the Client App's folder (if Blazor WASM) or Blazor Server App's folder.

Run these commands:

npm install -D tailwindcss cross-env
npx tailwindcss init

Create a new Hosted Blazor WASM, or Blazor Server project.

CD to the Client App's folder (if Blazor WASM) or Blazor Server App's folder.

Run these commands:

npm install -D tailwindcss cross-env
npx tailwindcss init

This will install Tailwind and the handy cross-env utility via NPM, then create a tailwind.config.js file.

Now update the tailwind.config.js file to include all your .razor and .cshtml files.

module.exports = {
  content: ["**/*.razor", "**/*.cshtml", "**/*.html"],
  theme: {
    extend: {},
  },
  plugins: [],
}

Now you'll want to create the Tailwind input stylesheet. This is the stylesheet that Tailwind will then pick up and build.

Here's the minimum you'll need...

Styles\input.css

@import "tailwindcss";

Finally, update your package.json file to add this script.

  "scripts": {
    "tailwind": "cross-env NODE_ENV=development ./node_modules/tailwindcss/lib/cli.js -i ./Styles/input.css -o ./wwwroot/css/output.css --watch"
  },

Make sure .Styles/input.css is pointing to the css file you created in the last step. You can control where the resulting css file is created by specifying your own value for the -o parameter.

That takes care of the Tailwind setup, now we just need to make this run when you run your ASP.NET Core project during Development.

Make sure you switch to the Server App's folder if you're using Blazor WASM (hosted).

Run this command to install the Tailwind AspNetCore NuGet package.

dotnet add package Tailwind.Extensions.AspNetCore

Now head over to Program.cs and add this code before app.Run();

if (app.Environment.IsDevelopment())
{
    _ = app.RunTailwind("tailwind", "./");
}

The second argument is the path to the folder containing your package.json file. If you're using Blazor WASM you'll probably need something like this...

if (app.Environment.IsDevelopment())
{
    _ = app.RunTailwind("tailwind", "../Client/");
}

You'll also need to add this using statement:

using Tailwind;

Note we're using the discard parameter _ when we call app.RunTailwind. This is because the method is async, but we don't want to wait for it to complete (as this would cause your app to wait for it to finish, and we want it continue running in the background alongside your app). Using the _ parameter here stops your IDE nagging at you to await the call 😀

Now, run dotnet watch run and try modifying your Razor components (using Tailwind's utility classes).

You should see logs indicating that tailwind has rebuilt the CSS stylesheet successfully.

You can use either approach depending on your preference:

• Tailwind CLI hosted service (recommended): configure via appsettings and call builder.UseTailwindCli();. No npm script required. Prefer this with the standalone Tailwind CLI on PATH or set via TailwindCliPath.
• npm script middleware (alternative): keep your Tailwind build as an npm script and call _ = app.RunTailwind("tailwind", "./"); in Development. This remains fully supported.