Client-side JS object operating proxy to Yext API is available and documented at https://github.com/sbm-it/yext.
Detailed documentation on Yext APIs can be found at http://developer.yext.com/docs. The location API is a good pace to start experimenting. Note also toy App at https://github.com/sbm-it/yextJonas.
There are many, most use indexedDB, some fall back to WebSQL. Here are 3 picks worthy of a closer look, for example, to process Yext AI call results in the App/browser.
http://hwcdn.libsyn.com/p/8/6/7/867bf897d5833fa6/MikeRoberts.m4a (podcast)
Hope the day is going well. I included below directions for accessing MongoDB University on-demand. Please feel free to forward the instructions to your colleagues.
Steps to Access On-Demand Training