Create a new ActionScript project in Visual Studio Code that targets the classic Apache Flex SDK - BowlerHatLLC/vscode-as3mxml Wiki

Learn to set up a project in Visual Studio Code to create an Apache Flex application that can run on Adobe AIR or Flash Player.

Development Setup

  1. Install the ActionScript & MXML extension for Visual Studio Code.

  2. Install the Apache Flex SDK (or you may use the legacy Adobe Flex SDK instead).

  3. Create a new directory for your project, and open it in Visual Studio Code.

    To open a directory, select the File menu → Open... or click Open Folder button in the Explorer pane.

  4. Set your workspace's SDK to the Flex SDK that you installed.

  5. Create a file named asconfig.json in the root directory of your project, and add the following content:

    	"compilerOptions": {
    		"source-path": [
    		"output": "bin/Main.swf"
    	"mainClass": "Main"

    An Adobe AIR project that targets desktop should set config to "air" instead, and a mobile project should set config to "airmobile". Additionally, you should specify the path to your AIR application descriptor (which we'll create in a moment). Here's an example for an AIR desktop project:

    	"config": "air",
    	"compilerOptions": {
    		"source-path": [
    		"output": "bin/Main.swf"
    	"mainClass": "Main",
    	"application": "src/Main-app.xml"
  6. Create directory named src.

  7. Inside src, create a file named Main.mxml, and add the following code:

    <?xml version="1.0" encoding="utf-8"?>
    <s:Application xmlns:fx=""
    	<s:Label text="Hello World" horizontalCenter="0" verticalCenter="0"/>

    Note: An Adobe AIR project that targets desktop should used WindowedApplication instead of Application.

  8. If you are building an AIR application, then create an AIR application descriptor file named Main-app.xml inside src. AIR application descriptors may be configured with many more elements, but you can use the following simple content as a starting point:

    <?xml version="1.0" encoding="utf-8" ?> 
    <application xmlns=""> 
    		<content>[Path to content will be replaced by Visual Studio Code]</content> 

    Be sure to update the version number in the namespace to match the version of Adobe AIR that you are targeting.

Next Steps