If you guys have not taken a look at emqx rule engine, it is a decent example of many of the features being requested. Connections / sources / rules is the hierarchy…. ex you create an mqtt connection sources link to a connection which are effectively your input data, topics, etc… rule contains an SQL like processing function that you link to a the source , and an output action like republishing on another topic… You can have multiple sources and multiple rules that use same or different connection It has enable toggles, and a testing feature that allows you to feed in your own payload or from the source. This is related to @Brian Pribe requests for broker drop down