ElasticSearch plugin which gets invoked after indexing a document

I am working on developing a plugin which can emit some metrics to one of our metrics storage service. I want this plugin to have access to the document after it gets indexed and use some fields from it to emit metrics (basically calling a web service with the data). The plugin should get invoked immediately (preferably asynchronously) after a document gets indexed. Does ElasticSearch plugin development framework support these requirements? Are there any open source plugins which I can inspire from?

Nothing I've seen, because there is nothing internal to ES to call a plugin after a document after it's been indexed.