Autodesk Developer Network

AutoCAD Plant 3D

The Plant SDK provides development tools for both AutoCAD® P&ID and AutoCAD® Plant 3D software.

AutoCAD P&ID software allows you to create, modify, and manage schematic piping and instrumentation diagrams.  AutoCAD Plant 3D adds 3D models, including piping, equipment, support structures, generation of isometric, and orthographic drawings.  AutoCAD Plant 3D includes the features of AutoCAD P&ID.  The Plant SDK supports both products.

Built on the familiar AutoCAD® software platform, AutoCAD P&ID and AutoCAD Plant 3D bring modern design to plant designers and engineers.  The Plant SDK extends the features of the ObjectARX SDK for AutoCAD.

Learn more about AutoCAD P&ID and AutoCAD Plant 3D in the product center.



Discussion Groups

You can also follow Plant 3D/P&ID API blogs at

Public discussion groups provide an open forum for sharing knowledge and receiving support. Join the following discussion groups:

You might also find useful software development information in the following AutoCAD Development Discussion Groups:


Samples and Documentation:
Several source code samples showing how to use the plant SDK are included with the SDK (download links below). These samples are located in the samples folder under PnID, Piping, and Common.

The Docs subfolder in the Plant SDK contains a developer guide (plantsdk_dev.chm), and a reference guide (plantsdk_ref.chm).


The Plant SDK includes an Application Program Interface (API) to extend the AutoCAD® API and provide software developers with a means to query and control P&ID schematic and project information, and the AutoCAD Plant 3D model.

In the Plant SDK, the AutoCAD® P&ID API is a subset of the Plant SDK. To create programs that will run on AutoCAD P&ID, do not reference Plant 3D-only interfaces. Plant 3D-only interfaces are identified in the Plant SDK reference guide included in the SDK.

To successfully utilize the APIs documented in this guide, developers should be familiar with ObjectARX and the .NET managed wrappers for ObjectARX.

When developing applications, you will be working with both the ObjectARX SDK for AutoCAD and the Plant SDK.

The Plant 3D SDK is formatted in the same way as the ObjectARX SDK, therefore, it is possible to simply overlay the Plant 3D SDK onto a pre-installed ObjectARX SDK.

Training and Support

If you need more professional customization support, consider joining the Autodesk Developer Network.

For more information on API Training please visit