AWS Appsync Scalar types and Apollo Federation

Hi Guys,

I’m currently facing a problem that I have no idea on how this could be solved with the federation gateway.
The setup that we have is that we are connecting the gateway to appsync.
Which works fine when not using the AWS scalar types Scalar types in AWS AppSync - AWS AppSync

As soon as one field uses e.g AWSJSON it fails the composition.

throw Error("A valid schema couldn't be composed. The following composition errors were found:\n" +
                  ^

Error: A valid schema couldn't be composed. The following composition errors were found:
        Unknown type: "AWSJSON".
        Unknown type "AWSJSON".
        Unknown type "AWSJSON".

The Issue that I is that i searched all the documentation and cannot find anything on how to add custom scalar types to the IntrospectAndCompose function. Since I think this should also have to be added on the gateway side - otherwise it will not know on how to parse/serialize these values

Some help here would be appreciated

Best

Jakub