The Newgrounds API can be used with Macromedia Flash 8, Adobe Flash CS3, and higher.
Download the Newgrounds API package from the Projects page.
You should download either the AS2 or AS3 package from the API Tools section of your project. To determine which package you need, open your Flash file and go to File, Publish Settings, and look under the Flash tab for the ActionScript version setting. Macromedia Flash 8 users should always use the AS2 package.
Open NewgroundsAPI.fla in the API package.
You should see the API components on the Stage.
Copy the API Connector component from NewgroundsAPI.fla into your project file.
You can copy and paste the components, or drag them into your Flash document. You should place the API Connector onto the first frame of your Flash file.
Enter your API Entry information into the API Connector parameters.
Click the API Connector in your Flash file. In Flash CS4 or lower, go to the Window menu, and select Component Inspector. In Flash CS5 or higher, look in the Properties tab. Enter your API ID and Encryption Key in the available fields. You can find your API entry information in the API Tools section of your project.
You are done!
Your project is now integrated with the Newgrounds API! You can can test your project by pressing Ctrl+Enter. If you integrated the API correctly, you should see successful connection messages in the Output panel. You can now copy other components from the NewgroundsAPI.fla as you need them.