es-mongodb-sync

Node.js package that synchronizes MongoDB collections with Elasticsearch indices by tailing the MongoDB oplog. Supports one-to-one and one-to-many mappings, attachment sync, and filtering. Compatible with Elasticsearch 6.x and MongoDB 3.6+. Currently at version 2.1.35, with no recent updates. Requires a MongoDB replica set. Key differentiator: real-time sync via oplog tailing without additional middleware.