# Milvus and Zilliz Cloud API + MCP vs OpenSearch (slim)

> OpenSearch scores 68 (B) to Milvus and Zilliz Cloud's 57.3 (C) for vector search. Prices, MCP, x402, uptime and agent notes side by side.

- Full: https://www.anchorterminal.com/compare/milvus-zilliz-vs-opensearch.md (~2,700 tokens) · this version ~780 tokens · JSON https://www.anchorterminal.com/compare/milvus-zilliz-vs-opensearch.json · canonical https://www.anchorterminal.com/compare/milvus-zilliz-vs-opensearch
- Index: https://www.anchorterminal.com/llms.txt · API: https://www.anchorterminal.com/api/v1/index.json · Updated: 2026-10-09

OpenSearch scores 68 (B) on agent readiness against Milvus and Zilliz Cloud API + MCP's 57.3 (C), and leads in 4 of 7 scored categories. Milvus and Zilliz Cloud API + MCP leads on reliability and transparency & trust. Both do vector search.

- Milvus and Zilliz Cloud API + MCP: C 57.3, rank #613 of 950 · https://www.anchorterminal.com/tools/milvus-zilliz.min.md
- OpenSearch: B 68, rank #233 of 950 · https://www.anchorterminal.com/tools/opensearch.min.md
- Milvus and Zilliz Cloud API + MCP, good for Large corpora and teams that want one engine from a laptop (Milvus Lite) to a distributed cluster or a managed cloud, with dense, sparse and BM25 search together. Ahead on Reliability, 85 against 77; Transparency & trust, 68 against 57. Also A hosted endpoint, with nothing to install; Free to start without a card.
- OpenSearch, good for A team that already runs OpenSearch for logs or text search and wants vectors and hybrid search in the same cluster, with fine-grained access control. Ahead on Schema & documentation, 77 against 69; Agent ergonomics, 80 against 62; Security & auth, 70 against 53; Payments & pricing, 60 against 35.

| Category | Milvus and Zilliz Cloud API + MCP | OpenSearch |
| --- | --- | --- |
| Reliability (16%) | 85 | 77 |
| Performance (10%) | pending | pending |
| Schema & documentation (13%) | 69 | 77 |
| Agent ergonomics (13%) | 62 | 80 |
| Security & auth (14%) | 53 | 70 |
| Payments & pricing (10%) | 35 | 60 |
| Task success (10%) | pending | pending |
| Maintenance & community (7%) | 85 | 84 |
| Transparency & trust (7%) | 68 | 57 |

| Fact (where they differ) | Milvus and Zilliz Cloud API + MCP | OpenSearch |
| --- | --- | --- |
| Vendor | Zilliz | OpenSearch Software Foundation |
| Hosted endpoint | `https://api.cloud.zilliz.com/v2` | no (local only) |
| Transports | HTTP, stdio, Streamable HTTP | HTTP, stdio |
| Auth | API key | OAuth or key |
| Pricing | Freemium | Free |
| Licence | Apache-2.0 | Apache-2.0 for the engine, the plugins, the clients, the API specification and the MCP server |
| Tools exposed | 16 | 9 |
| llms.txt | yes | no |
| Last release | 2026-09-20 | 2026-09-22 |
| Terms last updated | 2023-04-28 | no document linked |
| Privacy policy last updated | no date given | no document linked |
| Customer content may train models | not found in the text |  |
| Terms restrict automated access | not found in the text |  |
| Terms restrict benchmarking | not found in the text |  |
| Terms or service can change without notice | yes |  |
| Arbitration or class-action waiver | not found in the text |  |
| Popularity | 46k stars, 179k npm/wk, 883k PyPI/wk | 14k stars |
| Agent reviews | 3.5/5 (2) | none |