Json.NET - preserve type information when type is unknown

Question

I would like to send Json to the server, and we do that with Newtonsoft's Json.NET¹. The json may contain type information ("$type" = ...). This type info may point to an unknown type. Said object would typically be contained in a property of type object.

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What I would like to do:

• Convert the part of the unknown type to a JObject
• Preserve somehow the type information, so I can send the same json back to the client at a later point as it was passed to the server.

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What I've tried so far

• By replacing the SerializationBinder on the JsonSerializer, I can force Json.NET to deserialize the json contained into a JObject. This is almost what I would like to have, alas the $type property is lost.

• In the binder returning a type that points to an object that would work in harmony with a custom JsonConverter which would gobble up the offending object such that upon write it would faithfully recreate the json as it was encountered. However, when you hit the $type info, no converters will be called anymore, apparently we are then in a different branch of the json.NET code

• One can handle a serialization error, try to read from the reader the offending part, then one could create a JOBject manually and annotate the type information.

^{1) More specific - the built of it that is contained in the RavenDB.Abstractions, but hopefully they have not diverged too much.}