AutoCAD .NET Plugins (C# / VB.NET)
AutoCAD .NET plugins are managed C# or VB.NET DLLs that reference AcDbMgd/AcMgd to extend AutoCAD with new commands, ribbon tabs, and reactors. They load with NETLOAD or auto-load via an AutoCAD .bundle. CAD Exchange's .NET plugin listings always specify the supported AutoCAD versions because .NET plugins are version-locked.
What makes a great autocad .net plugins (c# / vb.net)
A great .NET plugin ships as an AutoCAD .bundle so it auto-loads, declares its supported AutoCAD version range in PackageContents.xml, registers commands with a clear prefix (CADEX*, BB*, etc.), uses transactions correctly (no orphaned Database/Editor references), and provides an uninstall path.
Common .NET plugin categories
- Ribbon-integrated drafting tools — multi-button suites that add a tab
- Reactor-based syncers — keep annotations or layers in sync with geometry
- Custom entity packs — proxy graphics for specialist domains (rebar, ducts)
- External data integrations — pull data from Excel, SQL, or REST APIs
- Civil 3D-cross plugins — work in both AutoCAD and Civil 3D
Browse AutoCAD .NET Plugins (C# / VB.NET) listings →
Frequently asked questions
Why are .NET plugins version-locked?
Each AutoCAD release ships a different AcDbMgd/AcMgd. A plugin compiled against the 2024 assemblies looks for those exact types at load; the 2025 assemblies are subtly different.
Do I need to install .NET separately?
No — AutoCAD installs the .NET runtime it needs. Plugins built against the version of .NET your AutoCAD ships with will load without separate installs.
How do I uninstall a .NET plugin?
Run the vendor's uninstaller if there is one. Otherwise delete the .bundle folder from %APPDATA%\Autodesk\ApplicationPlugins\ and remove any registry auto-load entries under HKCU\Software\Autodesk\AutoCAD\<ver>\<lang>\Applications\.
Can a .NET plugin be malicious?
Yes, in principle — .NET code has the same machine access as AutoCAD itself. CAD Exchange scans every uploaded DLL with automated decompilation and pattern analysis before listing, and Trusted Locations protects you from accidentally loading untrusted DLLs.
Install & how-to guides
Load a C# / VB.NET plugin DLL into AutoCAD with NETLOAD, troubleshoot common load errors, and set up auto-load so you don't NETLOAD every session.
Package a .NET plugin (or LISP) so AutoCAD picks it up automatically every session — no NETLOAD required.
Related categories
Buy and download verified AutoCAD automation: AutoLISP routines, .NET plugins, and ObjectARX add-ins. Reviewed by CAD pros, scanned for malware, version-locked to your AutoCAD release.
Hundreds of verified AutoLISP and Visual LISP routines for AutoCAD: .lsp source, compiled .fas, and bundled .vlx applications. Loaded with APPLOAD, version-friendly, malware-scanned.
Glossary
A managed assembly (C#/VB.NET DLL) that uses Autodesk's .NET API to add commands and behaviour to AutoCAD or Civil 3D.
The AutoCAD command that loads a managed .NET plugin DLL into the running session.
Two related AutoCAD mechanisms for loading plugins on demand: the (autoload) LISP function and the auto-load registry/bundle keys used for .NET DLLs.
The .NET attribute you place on a method to expose it as a typeable AutoCAD command after NETLOAD.
Autodesk's C++ runtime extension SDK for AutoCAD. The lowest-level, highest-performance way to extend AutoCAD.