An efficient server library for quickly creating a WebServer and handling HTTP requests, WebSocket connections, and routing API requests using the Dart language.

Includes extra nice features, such as setting a parameter to require Basic Authentication for a Url, with all of the difficult auth checking and responding taken care of by the server, plus much more!

Who is using this package?


  • Used for preprocessing and serving webpages and resources, serving API responses, and multiple other features.
  • Major backer: Guarantees long-term support for this project's concept. Thank you, SocialFlare!

Ebates, Inc.

  • For a handful of internal tools for organizing data and serving stat pages.
  • Used to serve a realtime Purchases Stat information webpage to merchant representatives at the Ebates MAX Conference built around this package.

Use Example (for no coding needed)

You can use this WebServer to serve files without even having to code a single line. Using Dart's pub global activate feature, you can add the WebServer package as an executable to call from the command line in any directory and serve files from it.

# Activate the WebServer globally.
pub global activate web_server
# Navigate to the Directory that you want to serve files from.
cd /path/to/directory

# Activate the WebServer on that Directory. Defaults to port 8080.
# May require 'sudo' on Mac/Linux systems to bind to port 80.
# For:
web_server --port=9090

For details on all of the possible arguments and uses:

# Use the 'help' argument
web_server --help

Please don't forget to run the pub global activate web_server command every once and a while to get the latest version of the WebServer package; Pub/Dart does not automatically update the package to avoid the risk of breaking changes.

Feel free to view the CHANGELOG before updating for documentation about whenever there is a breaking change. Skim quickly by looking for the bold text "Breaking Change:" before a "Tools > web_server" category change. It is safe to assume there will NOT be a breaking change unless the version number increases by 2.x; the 2.0+x format changes, for example, are non-breaking when the number after "+" is the only difference.

Features & Use Example (for coders)

Please check out the "example/" folder in this package for full details.

For preprocessing HTML like PHP

Use Angular-like variables, which will be converted using a helper method from this package (see Dart code below).


  <h1>Welcome, {{username}}!</h1>

  <p>The date today is: {{todayDate}}.</p>

Then, process variables like PHP on the Dart server side:


import "dart:io";
import "package:html/parser.dart" as domParser; // https://pub.dartlang.org/packages/html
import "package:html/dom.dart" as dom;
import "package:web_server/web_server.dart" as webServer;

void main() {
  // Initialize the WebServer  
  final webServer.WebServer localWebServer = new webServer.WebServer(InternetAddress.ANY_IP_V4, 8080,
        hasHttpServer: true);
    .forRequestPath(new webServer.UrlPath('/index.html')).onRequested.listen((final HttpRequest httpRequest) async {
      String indexFileContents = await new File('path/to/index.html').readAsString();
      // Apply the Dart variables to the HTML file's variables like
      // AngularJS/AngularDart
      indexFileContents = webServer.applyVarModifiers(indexFileContents, {
        "username": "mrDude",
        "todayDate": '${new DateTime.now()}'
      // ===== AND/OR =====
      // Interact with the HTML like client side Dart.
      final dom.Document document = domParser.parse(indexFileContents);
      // The HTML library has its own Element Objects; separate from the 'dart:html' ones.
      final dom.Element pElm = document.querySelector('p');
      pElm.remove(); // Remove the <p> Element from the document's DOM.
      // Add data to and close out the Http request's response.
          ..headers.contentType = new ContentType('text', 'html', charset: 'utf-8')
          // OR

For Hosting APIs

Filter every request starting with a certain Url pattern into a request handler.

import "dart:io";
import "package:web_server/web_server.dart" as webServer;

void main() {
  // Initialize the WebServer
  final webServer.WebServer localWebServer = new webServer.WebServer(InternetAddress.ANY_IP_V4, 8080,
        hasHttpServer: true);
      // NOTE: ApiHandler would be a Class or namespace created by you in your code, for example.
      ..handleRequestsStartingWith(new webServer.UrlPath('/api/categories')).listen(ApiHandler.forCategories)
      ..handleRequestsStartingWith(new webServer.UrlPath('/api/products')).listen(ApiHandler.forProducts)
      ..handleRequestsStartingWith(new webServer.UrlPath('/api/users')).listen((final HttpRequest httpRequest) {
        // Create the Object for the response
        final webServer.ApiResponse apiResponse = new webServer.ApiResponse()
            ..addData("username", "mrDude") // Add data
            ..addData("email", "radical_surfer@example.com")
            ..addData("userId", 1425302);

        // Send the data back through to the request
            // Set to "application/json; charset=utf-8"
            ..headers.contentType = ContentType.JSON
            // Stringify the JSON output, then send to client

Static File Directory/Basic WebServer

import "dart:io";
import "dart:async";
import "package:web_server/web_server.dart" as webServer;

Future<Null> main() async {
  // Initialize the WebServer  
  final webServer.WebServer localWebServer = new webServer.WebServer(InternetAddress.ANY_IP_V4, 8080,
        hasHttpServer: true);
  // Attach HttpServer pages and event handlers
  await localWebServer.httpServerHandler
      // Automatically recursively parse and serve all items in this
      // directory matching the accepted file types (optional parameter).
          supportedFileExtensions: const <String>['html', 'css', 'dart', 'js'], // Optional restriction
          shouldPreCache: true);

WebSocket Server

Let the WebServer automatically handle upgrading and connecting to WebSockets from the client side. The WebServer will forward data related to important events and automatically call your event listeners if you send data through a WebSocket from the client with the "cmd" parameter in the payload's Map Object.

import "dart:io";
import "package:web_server/web_server.dart" as webServer;

void main() {
  // Initialize the WebServer with the hasWebSocketServer parameter
  final webServer.WebServer localWebServer = new webServer.WebServer(InternetAddress.ANY_IP_V4, 8080,
          hasHttpServer: true, hasWebSocketServer: true);
  // HTTP Server handlers code here...
  // Attach WebSocket command listeners and base events
      // For automatically routing handling of data sent through a WebSocket with this pattern of "cmd":
      // {"cmd": 0, "data": { "pokemonCount": 151 }}
      ..on[0].listen((final webServer.WebSocketRequestPayload requestPayload) { /*...*/ })
      ..onConnectionOpen.listen((final webServer.WebSocketConnectionData connectionData) { /*...*/ })
      ..onConnectionError.listen((final WebSocket webSocket) { /*...*/ })
      ..onConnectionClose.listen((final WebSocket webSocket) { /*...*/ });

Add a custom ContentType

Allows the server to automatically pick up on this file extension as the supplied ContentType parameter when it is handling serving files.

HttpServerRequestHandler.addContentType('.html', new ContentType('text', 'html', charset: 'utf-8'));

Features and bugs

Please file feature requests and bugs using the GitHub issue tracker for this repository.

Using this package? Let me know!

I am excited to see if other developers are able to make something neat with this package. If you have a project using it, please send me a quick email at the email address listed on my GitHub's main page. Thanks a bunch!


A powerful WebServer package to make getting reliable, strong servers running quickly with many features.
An additional library for managing WebSocket connections that works very well with the WebServer library.