Build Custom Activities Easier Using the Latest UiPath Extension for Visual Studio

Try creating a few activities in the wizard and clicking the export button. It will give a good example of how the JSON is made.
Keep in mind that this extension creates the structure of an activity—the content and logic is left up to the developer.
We’re working on moving several of our projects to an open source repo for examples. Not sure when that will happen though.


Dear team,

Thank you for this extension and for the clear, step-by-step tutorial. It’s amazing how easy it is to create a custom activity now! Thanks also for the detailed documentation along with the tutorial.

I am trying to create a custom activity that converts Excel Workbooks into PDFs. To do this, I need to include the dll reference: Microsoft.Office.InterOp.Excel

When I run Visual Studio normally, I am able to find this library:


However, when I try to include the same reference in the UiPath Activity Builder, I am not successful. The library has a warning sign next to it…


“Could not resolve this reference. Could not locate the assembly “Microsoft.Office.Interop.Excel, Version=, Culture=neutral, PublicKeyToken=71e9bce111e9429c”. Check to make sure the assembly exists on disk.”

Team, @DeanMauro Could you please help me resolve this?

Thank you!

While dragging/selecting existing JSON file during import activity for UiPath project, getting error message “*.JSON is invalid” . Can someone suggest what can be the reason and possible solution.
Though existing project via UiPath studio is working fine.

I have tried to import existing activity (JSON file) in Uipath project of Visual studio 2019, but I am getting error message “project.JSON is invalid”. Any possible reason and solution for this issue?

Hello @mitesh,

Have you by any chance upgraded the UiPath Extention ? It’s possibe that you used a lower version of the Extention when you developed the activity and then the UiPath Extention got auto updated (Default behaviour). Let us know…


I just used the extension for Visual Studio to create a custom activity in order to use an external library. In particular, I added a NuGet package to the project but I noticed that instead of adding a dependency it included the .dll so that is fixed in the current version. How can I just add the dependency to that NuGet package so that every time it will use the latest version?
Also how can I use the types of data included in Uipath such Uipath.Core.Image?

is this extension is licensed or open source.
can i make a activity and publish on UIPATH Marketplace as our compny name


Hi Shashi,

Feel free to use the extension to create activities for your company and please do upload to the Marketplace :slight_smile: Anything you build with the Activity Creator is your property.

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Thank you very much @DeanMauro

You gave me a big relief
Again thanx

Hey Team, It is good to create simple activity.
But, No example given for creating application scope activity.
Can you please help me out on How to create scope activity with small example

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Hello @srihari.posanapalli,

Check this webinar starting at 45 min 50sec to learn how to use the actiity creator to build scope based activities. Special Thanks to @DeanMauro for the amazing demo !

Thanks & Regards,

Thanks for share
Can use it for create StudioX activity?