B

Elasticsearch MCP Server

DEPRECATED — Official Elastic MCP server for Elasticsearch data access: index listing, field mapping inspection, Query DSL search, ES|QL queries, and shard information. Superseded by Elastic Agent Builder endpoint in Elastic 9.2+.

Overall Score77/100

Score Breakdown

Server Info

Package
elasticsearch-core-mcp-server
Registry
cargo
Maintainer
ElasticVendor
Category
Developer Tools
Tags
searchanalyticslogs
Last Scanned
28 May 2026

Findings

5 issues

Authentication & Identity

HIGHNo MCP OAuth spec implementation

Server does not implement the MCP OAuth authorization server spec. The platform must handle the full OAuth flow, token management, and credential injection externally.

Remediation

Implement the MCP OAuth spec (.well-known/oauth-authorization-server) for native per-user authentication.

HIGHEnv var credentials with no rotation mechanism

Credentials (ES_URL, ES_API_KEY, ES_USERNAME) are read from environment variables at startup. Rotation requires restarting the server process. All requests share the same service account credential.

Remediation

Support dynamic credential refresh or secrets manager integration.

Tool Schema Quality

MEDIUMOnly 0 of 5 schemas have parameter constraints

Most schemas lack maxLength, enum, or pattern constraints on string parameters.

Remediation

Add constraints to string parameters, especially on write operations.

Permission Granularity

LOWTool descriptions lack resource scope

Descriptions don't specify what data types or resources they access.

Remediation

Add resource type statements to descriptions.

LLM Safety

MEDIUM2 tool descriptions are too vague

Short or generic descriptions make tool selection unreliable.

Remediation

Expand descriptions with specific actions, data types, and side effects.

Tools

5 total
NameDescriptionRisk
list_indicesList all available Elasticsearch indicesread
get_mappingsGet field mappings for a specific Elasticsearch indexread
searchPerform an Elasticsearch search with the provided query DSL.read
esqlPerform an Elasticsearch ES|QL query.read
get_shardsGet shard information for all or specific indices.read

Deploy Elasticsearch MCP Server securely

CompleteFlow adds per-user authentication, permission scoping, and audit logging to any MCP server out of the box.

Deploy on CompleteFlow