OpenSearch is an open-source search and analytics engine built on Apache Lucene and licensed under Apache 2.0. It was created in 2021 as a fork of Elasticsearch 7.10, after Elastic changed its license away from Apache 2.0 to the SSPL. Originally initiated by AWS, the project has been governed by the OpenSearch Software Foundation, a vendor-neutral Linux Foundation project, since September 2024. It shares its Lucene foundation with Solr and Elasticsearch, and is available both as self-managed software and as a managed offering through Amazon OpenSearch Service, as well as through third-party providers such as Aiven and Instaclustr. Typical use cases range from log and security analytics to e-commerce search and GenAI/RAG, supported by native vector search.
It is worth being clear about what OpenSearch is: infrastructure, not a ready-made e-commerce search solution. Setup, operation, and features such as merchandising or personalization require dedicated DevOps and development resources. Since version 3.0 (April 2025), OpenSearch has been based on Lucene 10, and the 3.x line has pushed heavily into hybrid and agentic search.