There is a glaring, painful hole in the current mBed IoT platform as it currently stands which unfortunately is something recurrent throughout the IoT ecosystem. There are no server functions. If your device is going to pulling and pushing to the mothership, and only the mothership, then the API they gave is adequate. However, if you want your IoT temperature nodes to be able to talk to your IoT vent register nodes, you have to have both of them polling the main server to fetch and get data, and have both become expensive paperweights when your internet connection drops.

It seems to be a recurrent problem with the mbed universe. The mbed editor, which they're going to be revamping Real Soon Now, has very much the same problem, where losing internet connectivity means that you're without an editor until whatever problem is corrected. IoT is only really going to be useful if the Things can talk back, otherwise, you're just going to have half-assed toys.