Harō is a modern immutable DataStore built with ES6 features, which can be wired to an API for a complete feedback loop. It is un-opinionated, and offers a plug'n'play solution to modeling, searching, & managing data on the client, or server (in RAM). It is a partially persistent data structure, by maintaining version sets of records in versions (MVCC). Synchronous commands return an Array instantly, while asynchronous commands return Promises which will resolve or reject in the future. This allows you to build complex applications without worrying about managing async code.