How to write C# components in Visual Studio for Grasshopper? If you have the Visual Studio community 2017, you have to also download assembler for grasshopper v6. https://marketplace.visualstudio.com/items?itemName=McNeel.GrasshopperAssemblyforv6 After downloading the file, start it. The VS community 2017 should be chosen automatically. Now you can start VS 2017 one more time, in the new project, you should find new options: If you choose Visual C# > Rhinoceros > Grasshopper Add-on for v6, a new window will appear: The missing files have to be added to references. The RhinoCommon and Rhino.exe you will probably find somewhere on C disc (in my case it is C:\Program Files\Rhinoceros 5 (64-bit) ). The Grasshopper.dll file location you should check on your disc through searching enginge ( in my case it was : C:\Program Files\Common Files\McNeel\Rhinoceros\5.0\Plug-ins\Grasshopper (b45a29b1-4343-4035-989e-044e8580d9cf)\0.9.76.0 ). Click finish and new empty code sh