... by design. Because there's no "string" type. This is a bug report about high level implementations that don't encode and decode in reversible ways, contrary to the msgpack protocol. http://wiki.msgpack.org/display/MSGPACK/Format+specification

Really, for a protocol that values minimal space usage, not defining a string type is probably a good thing. Use the one that produces the fewest bytes in your application - it may not be UTF-8.

Also:

>For instance, the objective C wrapper is currently broken because it tries to decode all raw bytes into high-level strings (through UTF-8 decoding) because using a text string (NSString) is the only way to populate a NSDictionary (map).

Well there's your problem: https://github.com/msgpack/msgpack-objectivec/blob/master/Me... It's a buggy wrapper that's trying to be convenient. And NSString keys are by no means the only way to populate an NSDictionary, and it doesn't look like the Objective-C wrapper requires this: https://github.com/msgpack/msgpack-objectivec/blob/master/Me...