This project hasn't reached 0.1.0 release yet and doesn't provide all planned functionality. use at your own desire to try new stuff.
This project maintains a declarative schema of various ElasticSearch options - types, type parameters, tokenizers, filters, etc. Such a schema allows to produce other projects (libraries, tools, etc.) that would be able to validate configurations, generate annotations, and do other meta-things automatically.
The goal of this project is to provide an API for various languages to get such schema for specific ElasticSearch version and ES plugins.
Available at https://ama-team.github.io/elasticsearch-schema/