AutoCAD API
Create solutions and enhance core software functionality
Autodesk AutoCAD® software is a platform for developing specialized design and drafting applications. Its open architecture and APIs allow for customization that extends to Autodesk industry-specific design software and a wide range of add-on applications created by the Autodesk Developer Network (ADN). AutoCAD provides programming environments including ObjectARX® with object-oriented C++ interfaces, the managed AutoCAD .NET API, the complete Visual LISP® development environment, and the ActiveX® interface.
APIs
AutoCAD has several different environments to help you customize and extend software functionality. The ObjectARX documentation is installed with the ObjectARX SDK and is available as part of the product Help.
Past AutoLISP guides
Past AutoLISP guides
Developer guides
Reference guides
Past ObjectARX guides
Past ObjectARX guides
Developer guides
Reference guides
Past AutoCAD JavaScript guides
Past AutoCAD JavaScript guides
Developer guides
Reference guides
Past ActiveX guides
Past ActiveX guides
Developer guides
The ActiveX documentation is installed with the program.
Reference guides
The ActiveX API documentation can also be found locally in these folders:
- %ProgramFiles%\Common Files\Autodesk Shared\acad_aag.chm
- %ProgramFiles%\Common Files\Autodesk Shared\acadauto.chm
Past Sheet Set Object guides
Past Sheet Set Object guides
The documentation related to this API is part of the product help.
Visual Studio integration
Visual Studio integration
The Managed .NET Reference guide can also be integrated with Microsoft Visual Studio.
- AutoCAD 2025 (supports Microsoft Visual Studio 2022)
- AutoCAD 2024 (supports Microsoft Visual Studio 2022)
- AutoCAD 2023 (supports Microsoft Visual Studio 2019)
- AutoCAD 2022 (supports Microsoft Visual Studio 2019)
Member and parameter descriptions from the Managed .NET Reference Guide can be displayed within the Microsoft Visual Studio environment as part of the Intellisense feature set. This allows for some basic information about a member or parameter to be displayed in a tooltip while working in a code editor window, or to be accessed from the Object Browser without the need to open the Help Viewer. These files are included in the SDK files and can be found in the same folder as the Managed .NET DLLs.
Past Managed .NET guides
Past Managed .NET guides
Developer guides
The components of the Managed .NET documentation are installed as part of the ObjectARX SDK and available as part of the product Help.
Reference guides
Past Connectivity Automation Object guides
Past Connectivity Automation Object guides
Past Transmittal Object guides
Past Transmittal Object guides
The documentation related to this API is part of:
Past CAD Standards Plug-in Object guides
Past CAD Standards Plug-in Object guides
The documentation related to this API is part of the product help.
Resources
DXF Reference
DXF Reference
The DXF™ Reference provides information on the DXF file format, and the group codes that can be used by a custom application to create and modify objects.
Tutorials
Download past ObjectARX training labs
Download past ObjectARX training labs
Download past .NET training labs
Download past .NET training labs
Tools
Download these templates and tools to help you create custom applications using ObjectARX and .NET for AutoCAD.
Download past ObjectARX Wizards
Download past ObjectARX Wizards
Download past AutoCAD DotNet Wizards
Download past AutoCAD DotNet Wizards
Community and support
Whether you're an experienced AutoCAD user or just starting out, this is a good place to ask questions, share tips, connect, and learn from others.