I need to do a bit more investigation into this, but I'm fairly certain this function should be deprecated. It accepts an encoder and decoder as parameters but the Callable type itself is initialized with an encoder/decoder so the properties should be used instead. Right now if you use the There's no equivalent completion based call.

I'm not sure we can actually deprecate this though as we need to replace it with something like this:

public func call(_ data: Request) async throws -> Response { ... }

but that would be in conflict with the default arguments.