We are actively working on browser developer tools for Starbeam.
Under the hood, these tools are built on top of the introspection APIs in @starbeam/timeline.
At the moment, there are two reflection APIs that are fleshed out and ready to use:
ReactiveProtocol.description, which returns the description of a reactive value, based on the stack frame in which it was created and any user-specified information.
ReactiveProtocol.debug, which returns a pretty-printed list of the reactive value's dependencies.