octodet-elasticsearch-mcp

Instructions

Implementation Reference

• src/index.ts:108-140 (handler)

  The handler function for the 'list_indices' tool. It takes an indexPattern, calls the Elasticsearch service to list matching indices, formats the response as MCP content with summary and JSON, or returns an error message.

    try {
      const indicesInfo = await esService.listIndices(indexPattern);
  
      return {
        content: [
          {
            type: "text",
            text: `Found ${indicesInfo.length} indices matching pattern '${indexPattern}'`,
          },
          {
            type: "text",
            text: JSON.stringify(indicesInfo, null, 2),
          },
        ],
      };
    } catch (error) {
      console.error(
        `Failed to list indices: ${
          error instanceof Error ? error.message : String(error)
        }`
      );
      return {
        content: [
          {
            type: "text",
            text: `Error: ${
              error instanceof Error ? error.message : String(error)
            }`,
          },
        ],
      };
    }
  }

• src/index.ts:101-107 (schema)

  Zod input schema for the 'list_indices' tool defining the indexPattern parameter.

    indexPattern: z
      .string()
      .trim()
      .min(1, "Index pattern is required")
      .describe('Pattern of Elasticsearch indices to list (e.g., "logs-*")'),
  },
  async ({ indexPattern }) => {

• src/index.ts:98-141 (registration)

  Registration of the 'list_indices' MCP tool on the server, including name, description, input schema, and handler reference.

    "list_indices",
    "List all available Elasticsearch indices with detailed information",
    {
      indexPattern: z
        .string()
        .trim()
        .min(1, "Index pattern is required")
        .describe('Pattern of Elasticsearch indices to list (e.g., "logs-*")'),
    },
    async ({ indexPattern }) => {
      try {
        const indicesInfo = await esService.listIndices(indexPattern);
  
        return {
          content: [
            {
              type: "text",
              text: `Found ${indicesInfo.length} indices matching pattern '${indexPattern}'`,
            },
            {
              type: "text",
              text: JSON.stringify(indicesInfo, null, 2),
            },
          ],
        };
      } catch (error) {
        console.error(
          `Failed to list indices: ${
            error instanceof Error ? error.message : String(error)
          }`
        );
        return {
          content: [
            {
              type: "text",
              text: `Error: ${
                error instanceof Error ? error.message : String(error)
              }`,
            },
          ],
        };
      }
    }
  );

• src/utils/elasticsearchService.ts:126-142 (helper)

  Core helper function in ElasticsearchService that queries ES cat.indices API to retrieve and parse index information matching the pattern.

  async listIndices(indexPattern: string): Promise<IndexInfo[]> {
    const response = await this.client.cat.indices({
      index: indexPattern,
      format: "json",
      h: "index,health,status,docs.count,store.size,pri,rep",
    });
  
    return response.map((index: any) => ({
      index: index.index,
      health: index.health,
      status: index.status,
      docsCount: parseInt(index["docs.count"] || "0", 10),
      storeSize: index["store.size"] || "0",
      primaryShards: parseInt(index.pri || "0", 10),
      replicaShards: parseInt(index.rep || "0", 10),
    }));
  }

• src/utils/models.ts:14-22 (schema)

  TypeScript interface defining the structure of IndexInfo returned by listIndices.

  export interface IndexInfo {
    index: string;
    health: string;
    status: string;
    docsCount: number;
    storeSize: string;
    primaryShards: number;
    replicaShards: number;
  }