This is a slightly revised version of the Cluster Example provided here.

A couple of things I added:

• Works off a URL instead of a data option, like a FeatureLayer.
• Option to add a Font for the Clusters TextSymbol. Default is 10pt and Arial.
• A zoomOnClick option that will zoom the map 1 zoom level on the clicked cluster graphic.
• Has an outFields option for the Features returned.

Although this behaves similar to a FeatureLayer, it does not have all the optimizations of a FeatureLayer. There is no Vector Tiling for the points. A possible optimization could be to break up the request by objectIds in to multiple queries. I added the ability to send requests by objectIds in chunks of 1000 by default. Can be set in options. I also added a cache for clustered graphics and a clearCache() method.

A demo can be seen here.