This README is for EmbedIO v2.x. Click here if you are using EmbedIO v1.x.

Overview

A tiny, cross-platform, module based, MIT-licensed web server for .NET Framework and .NET Core.

  • Written entirely in C#, using our helpful library SWAN
  • Network operations use the async/await pattern: Responses are handled asynchronously
  • Multiple implementations support: EmbedIO can use Microsoft HttpListener or internal Http Listener based on Mono/websocket-sharp projects
  • Cross-platform: tested on multiple OS and runtimes. From Windows .NET Framework to Linux MONO.
  • Extensible: Write your own modules -- For example, video streaming, UPnP, etc. Check out EmbedIO Extras for additional modules
  • Small memory footprint
  • Create REST APIs quickly with the out-of-the-box Web API module
  • Serve static or embedded files with 1 line of code (also out-of-the-box)
  • Handle sessions with the built-in LocalSessionWebModule
  • WebSockets support
  • CORS support. Origin, Header and Method validation with OPTIONS preflight
  • Supports HTTP 206 Partial Content
  • And many more options in the same package

Some notes regarding WebSocket and runtimes support:

Runtime HTTP implementation WebSocket support Notes
NET452 Unosquare and Microsoft Yes Support Win7+ OS, Linux and macOS.
NET47 Unosquare and Microsoft Yes
NETSTANDARD13 Unosquare Yes Support Windows, Linux and macOS using native System.Net library
NETSTANDARD20 Unosquare and Microsoft Yes Support Windows, Linux and macOS using native System.Net library
UAP Unosquare No Support Windows Universal Platform. More information here

EmbedIO 2.0 - What's new

Breaking changes

  • WebApiController is renewed. Reduce the methods overhead removing the WebServer and Context arguments. See example belows.
  • RoutingStrategy.Regex is the default routing scheme.

Additional changes

  • IHttpListener is runtime/platform independent, you can choose Unosquare HttpListener implementation with NET47 or NETSTANDARD20. This separation of implementations brings new access to interfaces from common Http objects like IHttpRequest, IHttpContext and mor.
  • IWebServer is a new interface to create custom web server implementation, like a Test Web Server where all the operations are in-memory to speed up unit testing. Similar to TestServer from OWIN
  • General improvements in how the Unosquare HttpListner is working and code clean-up.

Note - We encourage to upgrade to the newest EmbedIO version. Branch version 1.X will no longer be maintained, and issues will be tested against 2.X and resolved just there.

Some usage scenarios:

  • Write a cross-platform GUI entirely using React/AngularJS/Vue.js or any Javascript framework
  • Write a game using Babylon.js and make EmbedIO your serve your code and assets
  • Create GUIs for Windows services or Linux daemons
  • Works well with LiteLib - add SQLite support in minutes!
  • Write client applications with real-time communication between them using WebSockets
  • Write internal web server for Xamarin Forms applications

Installation:

You can start using EmbedIO by just downloading the nuget.

Package Manager

PM> Install-Package EmbedIO

.NET CLI

> dotnet add package EmbedIO

Examples

Basic Example:

Please note the comments are the important part here. More info is available in the samples.

namespace Unosquare
{
    using System;
    using Unosquare.Labs.EmbedIO;
    using Unosquare.Labs.EmbedIO.Modules;

    class Program
    {
        /// <summary>
        /// Defines the entry point of the application.
        /// </summary>
        /// <param name="args">The arguments.</param>
        static void Main(string[] args)
        {
            var url = "http://localhost:9696/";
            if (args.Length > 0)
                url = args[0];

            // Our web server is disposable.
            using (var server = new WebServer(url))
            {
                // First, we will configure our web server by adding Modules.
                // Please note that order DOES matter.
                // ================================================================================================
                // If we want to enable sessions, we simply register the LocalSessionModule
                // Beware that this is an in-memory session storage mechanism so, avoid storing very large objects.
                // You can use the server.GetSession() method to get the SessionInfo object and manupulate it.
                // You could potentially implement a distributed session module using something like Redis
                server.RegisterModule(new LocalSessionModule());

                // Here we setup serving of static files
                server.RegisterModule(new StaticFilesModule("c:/web"));
                // The static files module will cache small files in ram until it detects they have been modified.
                server.Module<StaticFilesModule>().UseRamCache = true;
                server.Module<StaticFilesModule>().DefaultExtension = ".html";
                // We don't need to add the line below. The default document is always index.html.
                //server.Module<Modules.StaticFilesWebModule>().DefaultDocument = "index.html";

                // Once we've registered our modules and configured them, we call the RunAsync() method.
                server.RunAsync();

                // Fire up the browser to show the content if we are debugging!
#if DEBUG
                var browser = new System.Diagnostics.Process()
                {
                    StartInfo = new System.Diagnostics.ProcessStartInfo(url) { UseShellExecute = true }
                };
                browser.Start();
#endif
                // Wait for any key to be pressed before disposing of our web server.
                // In a service, we'd manage the lifecycle of our web server using
                // something like a BackgroundWorker or a ManualResetEvent.
                Console.ReadKey(true);
            }
        }
    }
}

Fluent Example:

Many extension methods are available. This allows you to create a web server instance in a fluent style by dotting in configuration options.

namespace Unosquare
{
    using System;
    using Unosquare.Labs.EmbedIO;

    internal class Program
    {
        /// <summary>
        /// Defines the entry point of the application.
        /// </summary>
        /// <param name="args">The arguments.</param>
        private static void Main(string[] args)
        {
            var url = "http://localhost:9696/";
            if (args.Length > 0)
                url = args[0];

            // Create Webserver and attach LocalSession and Static
            // files module and CORS enabled
            var server = WebServer
                .Create(url)
                .EnableCors()
                .WithLocalSession()
                .WithStaticFolderAt("c:/web");

            var cts = new CancellationTokenSource();
            var task = server.RunAsync(cts.Token);

            Console.ReadKey(true);
            cts.Cancel();

			// Wait before dispose server
            task.Wait();
            server.Dispose();
        }
    }
}

REST API Example:

The WebApi module supports two routing strategies: Wildcard and Regex. By default, the WebApi module will use the Regex Routing Strategy trying to match and resolve the values from a route template, in a similar fashion to Microsoft's Web API.

A method with the following route /api/people/{id} is going to match any request URL with three segments: the first two api and people and the last one is going to be parsed or converted to the type in the id argument of the handling method signature. Please read on if this was confusing as it is much simpler than it sounds. Additionally, you can put multiple values to match, for example /api/people/{mainSkill}/{age}, and receive the parsed values from the URL straight into the arguments of your handler method.

During server setup:

var server =  new WebServer("http://localhost:9696/", RoutingStrategy.Regex);

server.RegisterModule(new WebApiModule());
server.Module<WebApiModule>().RegisterController<PeopleController>();

And our controller class (using default Regex Strategy) looks like:

public class PeopleController : WebApiController
{
    public PeopleController(IHttpContext context)
    : base(context)
    {
    }

    [WebApiHandler(HttpVerbs.Get, "/api/people/{id}")]
    public bool GetPeople(int id)
    {
        try
        {
            if (People.Any(p => p.Key == id))
            {
                return this.JsonResponse(People.FirstOrDefault(p => p.Key == id));
            }
        }
        catch (Exception ex)
        {
            return this.JsonExceptionResponse(ex);
        }
    }
    
    // You can override the default headers and add custom headers to each API Response.
    public override void SetDefaultHeaders() => this.NoCache();
}

The previous default strategy (Wildcard) matches routes using the asterisk * character in the route. For example:

  • The route /api/people/* will match any request with a URL starting with the two first URL segments api and people and ending with anything. The route /api/people/hello will be matched.
  • You can also use wildcards in the middle of the route. The route /api/people/*/details will match requests starting with the two first URL segments api and people, and end with a details segment. The route /api/people/hello/details will be matched.

During server setup:

var server =  new WebServer("http://localhost:9696/", RoutingStrategy.Regex);

server.RegisterModule(new WebApiModule());
server.Module<WebApiModule>().RegisterController<PeopleController>();
public class PeopleController : WebApiController
{
    public PeopleController(IHttpContext context)
    : base(context)
    {
    }

    [WebApiHandler(HttpVerbs.Get, "/api/people/*")]
    public bool GetPeople()
    {
        try
        {
            var lastSegment = this.Request.Url.Segments.Last();
            if (lastSegment.EndsWith("/"))
                return this.JsonResponse(People);

            int key = 0;
            if (int.TryParse(lastSegment, out key) && People.Any(p => p.Key == key))
            {
                return this.JsonResponse(People.FirstOrDefault(p => p.Key == key));
            }

            throw new KeyNotFoundException("Key Not Found: " + lastSegment);
        }
        catch (Exception ex)
        {
            return this.JsonExceptionResponse(ex);
        }
    }
}

The SetDefaultHeaders method will add a no-cache policy to all Web API responses. If you plan to handle a differente policy or even custom headers to each different Web API method we recommend you override this method as you need.

WebSockets Example:

During server setup:

server.RegisterModule(new WebSocketsModule());
server.Module<WebSocketsModule>().RegisterWebSocketsServer<WebSocketsChatServer>("/chat");

And our web sockets server class looks like:

/// <summary>
/// Defines a very simple chat server
/// </summary>
public class WebSocketsChatServer : WebSocketsServer
{
    public WebSocketsChatServer()
        : base(true, 0)
    {
        // placeholder
    }

    public override string ServerName => "Chat Server"

    protected override void OnMessageReceived(WebSocketContext context, byte[] rxBuffer, WebSocketReceiveResult rxResult)
    {
        var session = this.WebServer.GetSession(context);
        foreach (var ws in this.WebSockets)
        {
            if (ws != context)
                this.Send(ws, rxBuffer.ToText());
        }
    }

    protected override void OnClientConnected(WebSocketContext context)
    {
        this.Send(context, "Welcome to the chat room!");
        
        foreach (var ws in this.WebSockets)
        {
            if (ws != context)
                this.Send(ws, "Someone joined the chat room.");
        }
    }

    protected override void OnFrameReceived(WebSocketContext context, byte[] rxBuffer, WebSocketReceiveResult rxResult)
    {
        return;
    }

    protected override void OnClientDisconnected(WebSocketContext context)
    {
        this.Broadcast("Someone left the chat room.");
    }
}

Related Projects and Nugets

Name Author Description
Butterfly.EmbedIO Fireshark Studios, LLC Implementation of Butterfly.Core.Channel and Butterfly.Core.WebApi using the EmbedIO server
embedio-cli Unosquare A dotnet global tool that enables start any web folder or EmbedIO assembly (WebAPI or WebSocket) from command line.
EmbedIO.BearerToken Unosquare Allow to authenticate with a Bearer Token. It uses a Token endpoint (at /token path) and with a defined validation delegate create a JsonWebToken. The module can check all incoming requests or a paths
EmbedIO.LiteLibWebApi Unosquare Allow to expose a sqlite database as REST api using EmbedIO WebApi and LiteLib libraries
EmbedIO.OWIN Unosquare EmbedIO can use the OWIN platform in two different approach: You can use EmbedIO as OWIN server and use all OWIN framework with EmbedIO modules.
Microsoft.AspNetCore.Server.EmbedIO Dju EmbedIO web server support for ASP.NET Core, as a drop-in replacement for Kestrel