How to Build a Custom Add-in for Autodesk Products: Beginner’s Tutorial

Creating a custom add-in for Autodesk products is an excellent way to enhance workflow efficiency, add automation, and customize features for your specific design needs. This beginner-friendly tutorial will guide you through the essential steps for building your first Autodesk add-in using common tools such as Visual Studio and the Autodesk API.

What Is an Autodesk Add-in?

An Autodesk add-in is an extension that allows users to add new commands, automate repetitive tasks, and create custom tools inside software like AutoCAD, Fusion 360, and Revit. With the support of the Autodesk API, developers can write scripts and commands that greatly improve productivity and design accuracy.

Required Tools

• Visual Studio (Community Edition recommended)
• .NET Framework / .NET 6 depending on Autodesk product
• Autodesk API SDK (AutoCAD .NET API, Revit API, or Fusion 360 API)

Step 1: Set Up Your Project

Start by creating a new Class Library project in Visual Studio. This project will serve as the foundation of your Autodesk add-in.

// Basic C# template for Autodesk add-in project
using Autodesk.AutoCAD.Runtime;

public class MyFirstAddin : IExtensionApplication
{
    public void Initialize()
    {
        // Initialization code for the Autodesk add-in
    }

    public void Terminate()
    {
        // Cleanup code for the Autodesk add-in
    }
}

This simple structure is required for AutoCAD add-ins and demonstrates how the API initializes your plugin. Keywords like Autodesk add-in tutorial and AutoCAD .NET API help search engines recognize the topic naturally.

Step 2: Create a Custom Command

With the base structure ready, you can now create a custom command that will run inside Autodesk software.

// Creating a custom command in AutoCAD
using Autodesk.AutoCAD.Runtime;
using Autodesk.AutoCAD.ApplicationServices;
using Autodesk.AutoCAD.EditorInput;

public class Commands
{
    [CommandMethod("HELLOADDIN")]
    public void HelloAddIn()
    {
        Editor editor = Application.DocumentManager.MdiActiveDocument.Editor;
        editor.WriteMessage("\nYour Autodesk add-in is working!");
    }
}

This command adds a simple message output in AutoCAD. It is a perfect first step for beginners learning how to build custom Autodesk commands.

Step 3: Add the .bundle Folder

Autodesk products require your add-in files to be placed inside a .bundle folder that contains a PackageContents.xml file.

<ApplicationPackage 
    SchemaVersion="1.0" 
    AutodeskProduct="AutoCAD" 
    Name="MyFirstAddin" 
    AppVersion="1.0">

    <Components>
        <ComponentEntry 
            AppName="MyFirstAddin.dll" 
            LoadOnAutoCADStartup="true" />
    </Components>

</ApplicationPackage>

This XML configuration file tells AutoCAD how to load your add-in. It is used widely in Autodesk customization and plugin development.

Step 4: Load the Add-in

After placing your .dll inside the .bundle folder, copy the folder to:

C:\ProgramData\Autodesk\ApplicationPlugins\

Restart AutoCAD and run your command using:

HELLOADDIN

If everything works, you have successfully completed your first Autodesk add-in development tutorial for beginners.

Final Tips

• Study the Autodesk API documentation for deeper customization.
• Use code refactoring tools to keep your add-in easy to maintain.
• Experiment with UI elements such as Ribbon Panels and Custom Buttons.

By following each step carefully, you will quickly understand how to build powerful and professional-level Autodesk add-ins that improve design workflow and automation.

Autodesk, Add-in Development, AutoCAD API, Revit API, Fusion 360 API, Plugin Tutorial, .NET Programming, CAD Customization