Amazon OpenSearch Service now supports OpenSearch version 3.5

You can now run OpenSearch version 3.5 on Amazon OpenSearch Service. OpenSearch 3.5 introduces significant improvements in agentic AI capabilities, search relevance tooling, and observability features to help you build powerful agentic applications. With this launch, [agentic conversation memory](https://docs.opensearch.org/latest/ml-commons-plugin/api/agent-apis/execute-agent/) captures conversation context and tool reasoning in persistent storage, enabling your agents to provide coherent, accurate responses across multi-turn conversations. In addition to this, [context management](https://docs.opensearch.org/latest/ml-commons-plugin/context-management) optimizes what you send to large language models (LLMs) through automatic truncation and summarization, reducing your token costs while maintaining response quality. Finally a redesigned no-code agent interface supports Model Context Protocol (MCP) integration, search templates, conversational memory, and single model configurations, allowing you to build sophisticated agents without writing code. You can now tune search quality faster with expanded [search relevance workbench](https://docs.opensearch.org/latest/search-plugins/search-relevance/using-search-relevance-workbench/) capabilities. LLM-powered evaluation automatically assesses search results with customizable prompts, letting you scale relevance testing beyond manual judgments and accelerate quality improvements. Scheduled experiments run tests nightly, weekly, or monthly, helping you track search quality trends over time and catch regressions early. Enhanced single query comparison displays agentic search queries alongside agent summaries, making it easier to validate and optimize agent-driven search experiences. For information on upgrading to OpenSearch 3.5, please see the [documentation](https://docs.aws.amazon.com/opensearch-service/latest/developerguide/version-migration.html). OpenSearch 3.5 is now available in all AWS Regions where Amazon OpenSearch Service is available.