A simple client-server example of automerge in action.

One of the issues for newcomers to Automerge is the lack of familiarity with the flexibility in network topology that a state synchronization algorithm like it brings. For example, most web developers are used to a server that listens for client connections--a star topology where the server is always on, and the clients are ephemeral.

While automerge offers many other possible configurations (e.g. peer-to-peer, federated, server-to-server, multi-master-write etc.) I felt it needed a simple example of a familiar topology to get people started. simplemerge is that example.

$ yarn install

The server runs a websocket, listening for connections on port 8080:

$ yarn run server

The server holds a single connections document that tracks new peers as they connect to the server. Each peer is given access to this connections document so that peers can become aware of each other and start to communicate.

The server also syncs any documents that any of its clients offers up--so if a client creates a new example JSON document, that document will be synced with the server, but with access restricted to just that server-client relationship.

The client is a static HTML page with javascript. It uses parcel as a web packager, and can be started in the same way as the server:

$ yarn run client

Once started, open it up at http://localhost:1234.