AutoCAD.NET.Interop for AutoCAD 2026

[kw_friday]

I'm in the process of updating our customization for ACAD. The update for the nuget package for AutoCAD.net.interop (2026.0.0.9999) seem to be missing the two .dll needed. Has anyone else found this to be the case, or am I missing something? My progress is at a standstill until I can get the full nuget package. I have emailed the author of the package but have not gotten any reply. 

[norman.yuan]

There is certainly no reason to hold your development progress at standstill just because of the need to have references to AutoCAD COM interop.

The Nuget package for AutoCAD custom .NET app development is not a "MUST-HAVE", especially for AutoCAD's COM interop DLLs. They comes with AutoCAD installation, you you can set references in your project directly to the interop DLLs in the AutoCAD installation (make sure Copy Local is set to false). Not sure how you you are going to use COM API, but I'd try to use late binding (using dynamic type in C#) whenever possible, thus, not need to have reference to the interop DLLs and make my code version-independent. 

[kw_friday]

I'm not sure if this matters, but all my code is vb.net previously using framework. Now, upgrading from 2024 to 2026, I need to use .net8 and unless I use the nuget AutoCAD.NET.Interop 2025.25.0.58 the code will not compile. Because those dll's are meant for 2025 they create compatibility errors when run. When I download the 2026 version, it is missing the dlls. and will not compile.

[norman.yuan · Accepted solution]

It looks like you need to first do some study on moving your CAD development from Acad2024 or older to Acad2025/2026 (that is, from using .NET Framework 4.x to .NET 8), also be aware, once the project is omved/converted to support .NET 8, the app would not run in Acad 2024 or older. 

Again, I repeat, regardless of using VB.NET or C#, the Nuget package for AutoCAD .NET development is not a MUST -HAVE, especially for AutoCAD .NET COM API interop DLLs. If you do not use COM API interop DLL, then, there will be no different from using Nuget package for .NET API dlls for Acad2025, or 2026, against AutoCAD 2026. However, if you do using COM Interop DLLs as references (early binding), then you need set reference to the AutoCAD version you are targeting. In this case, I'll say it one more time: you can set references to the COM Interop DLLs (Autodesk.AutoCAD.Interop.dll/Autodesk.AutoCAD.Interop.common.dll) directly in the AutoCAD installation, or the ones come with ObjectARX SDK, if you downloaded it. Absolutely no need to hold your work to find Nuget package, if you could not find it.

I actually guess that you would have more issues on moving your development project from .NET Framework to .NET 8 in general.

On side note, you may want to drop VB.NET and adopt C# as as soon as possible: MS has stoppedVB.NET advancement since .NET 6 and you would feel more language gaps between VB.NET and C# with later AutoCAD versions (it is possible that next version of AutoCAD might target .NET 10).

[kw_friday]

Thanks for your help!