The whole jsreport sdk for .NET is open sourced on github. We welcome every contribution.
The sources as well as release notes can be found in the sdk home repository: jsreport/jsreport-dotnet
All of the .NET packages and repositories are free and MIT licensed and you are welcome to contribute. See the home repository for further details. Note that the jsreport binary itself is also free but with limitation to 5 stored templates. You are also free to go if you don't store templates inside jsreport and generate html using razor for example.