I forgot to disclose in my original post that I am a staff engineer with the C++ Alliance, so I am doing so now. Back to the review... If TLS, the most important protocol in networking, can be made sans I/O, so can all the others. The thing with Redis and MQTT is that there's no shortage of quality production-ready libraries in the wild. In my mind, there's no strong onus to actually get a lib like Redis or async-mqtt5 into Boost because, well, you can just use any number of competitor libs and ship your product. I think for Boost, we should strive for something actually cutting-edge, something that lives up to the reputation. For IoT devices, you're not going to be able to use Asio. I was chatting with another engineer who was talking about how his MQTT code is used in thousands of devices in people's homes. Except he does all this on top of libuv, meaning Boost is a non-starter in this regard. I think in many ways, having a clean sans-I/O layer will probably actually make the I/O parts cleaner. It works really well for TLS and HTTP. I don't see why MQTT is different. - Christian