I'm interested in developing plugins for fuzzy hashes, including ssdeep, sdhash, and LZJD. I did find something similar, an existing ssdeep plugin for Elasticsearch in Python, but I'd prefer to write the code in Java, since it's likely faster, and some of the fuzzy hash code is in Java anyway.
I did find a plugin for Murmur3, which is similar. But I don't see how the API works for storing, querying with a hash to get similarity, and how to return similar documents and adding a new field which is the similarity value (integer between zero and 100).
I'm working on a project where I'd like to be able to find similar documents based on the fuzzy hash, and the documents are metadata for raw binary files. These fuzzy hashes would work for text documents too (ssdeep was developed to detect spam emails).
Is there an API document to handle custom fields, mappings, and adding to the search result JSON?