Building a web-based SES REPL

Does anyone know of a web front-end REPL library that could be connected to a SES container, to provide a REPL into a SES context?

I think this could be a fun way to demonstrate SES security, and also be a generally nice way to expose permission-limited REPLs into sites in general.

This is not quite what you’re asking for, but it could be a good starting point to building an actual REPL: