@Marcu5 great! MessageToByteEncoder is useful if you have a “message” for example your own data type (usually a struct) that you want to encode to the wire protocol. For example you might use JSONEncoder in there. But currently, if you already have many bytes as ByteBuffer it’s not super useful because you wouldn’t want to copy them (as you said). Possibly, we could in the future add API that supports this. But then, writing simple encoding ChannelOutboundHandlers is actually simple enough...