[Perceptes]

In terms of OSI layer 7 protocol, Matrix uses HTTP, though in the future it may specify other application protocols.

[rajanchandi]

The problem with HTTP is that it drains 11 times more battery on a mobile phone than something like MQTT.

[Arathorn]

As Perceptes says, Matrix is designed to have modular transports. So if you want to use MQTT or CoAP or WebSockets or whatever for the client/server API, then go for it :) PRs welcome!

[gmfawcett]

Can you give any evidence to support that statement?

[akerro]

[sources required]