[oblib]

"Multi-tenancy"

That term is new to me but after reading a few descriptions I think that CouchDB 2.0 is designed in a way that may provide those capabilities.

It has built-in authentication and uses "Users" and "Roles" and "Design Documents" that provide controls and methods to create and access data on a specific database.

http://docs.couchdb.org/en/2.1.0/

You might want to look into PouchDB.js as well as the CouchDB Docs.

https://pouchdb.com