AutoCouch: A JSON CRDT Framework

Abstract

Most web-based applications require an undisrupted connection to some kind of server for updating the current application state and propagating changes made locally at the clients. By their very nature, CRDTs provide the right semantics for these applications as they resolve conflicts after concurrent state changes from different users or when a user reconnects after some period of unavailability. Although the JSON format is often used to summarize and represent the complete state of web applications, there is currently – to our knowledge – no generic integrated implementation of a JSON CRDT framework that supports the standard client-server setup for web apps. In this paper, we present the AutoCouch framework which combines the benefits of the Automerge CRDT library with the widely used CouchDB framework. It provides an out-of-the-box use of a conflict-free JSON document that is replicated on server side and in browsers on client side, while requiring few adaptations to provide smooth online/offline transitions for web apps.