Worldwide Sites

You have been detected as being from . Where applicable, you can see country-specific product information, offers, and pricing.

Change country/language X

Keyboard ALT + g to toggle grid overlay

AutoCAD ObjectARX SDK Developer Center

Frequently Asked Questions

  • What versions of ObjectARX are available?
    You can download ObjectARX® software for the latest five releases of AutoCAD® and AutoCAD® for Mac® software products. Starting with 2020, only a 64-bit version of ObjectARX is available for the Windows® platform.

  • How do I get the ObjectARX software development kit (SDK)?
    The complete ObjectARX SDK and license agreement are available for download at no charge.

  • What is the difference between RealDWG and ObjectARX for AutoCAD?
    The RealDWG™ application is a subset of ObjectARX and contains the APIs for reading and writing DWG™ and DXF™ files. RealDWG does not contain support for viewing and accessing the AutoCAD user interface.ObjectARX applications always require AutoCAD as their host application. RealDWG does not require the presence of AutoCAD software. RealDWG can be used to create independent host applications. ObjectARX cannot.

  • What documentation is available for developing applications in ObjectARX?
    The following publications are included with the ObjectARX SDK:
    • Managed Class Developer’s Guide
    • Managed Class Reference
    • ObjectARX Developer’s Guide
    • ObjectARX Reference
    • Application Interoperability Guidelines
    • ObjectARX Migration Guide
    • Links to other valuable developer reference materials are listed at

  • Is developer support or training available for ObjectARX?
    Yes. Support is available through the Autodesk public forums ( or through membership of the Autodesk Developer Network ( ObjectARX training material is available for download from

  • Do I have to rebuild my older AutoCAD applications to work on the latest version of AutoCAD?
    It depends on the version of AutoCAD and whether it was designated as a binary compatible release. Always check the developer's guide for details. For example, as AutoCAD 2022 is not a binary breaking release, applications built with ObjectARX for AutoCAD 2021 will work with AutoCAD 2022. However, applications developed using ObjectARX 2020 need to be recompiled for use with AutoCAD 2021-based products.