Achievement unlocked! With the merge of Pull Request #213 (PR #213), Kenji Uno added support for Visual Studio Design Time also known as DDEX. A most wanted feature From the statistics of pageviews I get from a previous post about design time support, I can affirm that this is a most wanted feature of Npgsql. And I'm very glad to say that Npgsql is finally having it. I'd like to thank Kenji Uno for all his hard work to make this happen. Npgsql DDEX support is done through an extension file which can be easily installed in Visual Studio. This is a much better situation than we had before where it was needed to use an experimental instance of Visual Studio. History The code started with wwindcloud in PR #67 and Kenji started to play with it and said he was working to get it usable in VS2012 and 2013 . Some time later, Kenji said he had some success to get Npgsql DDEX initially working and started to fix the bugs he was fi...