Elasticsearch MCP Server

Instructions

Implementation Reference

• src/tools/getMappings.ts:3-42 (handler)

  The handler function that fetches Elasticsearch index mappings using the Elasticsearch client and returns formatted text content with the mappings or error message.

  export async function getMappings(esClient: Client, index: string) {
    try {
      const mappingResponse = await esClient.indices.getMapping({
        index,
      });
  
      return {
        content: [
          {
            type: "text" as const,
            text: `Index mapping: ${index}`,
          },
          {
            type: "text" as const,
            text: `Index ${index} mapping: ${JSON.stringify(
              mappingResponse[index]?.mappings || {},
              null,
              2
            )}`,
          },
        ],
      };
    } catch (error) {
      console.error(
        `Failed to get mapping: ${
          error instanceof Error ? error.message : String(error)
        }`
      );
      return {
        content: [
          {
            type: "text" as const,
            text: `Error: ${
              error instanceof Error ? error.message : String(error)
            }`,
          },
        ],
      };
    }
  } 

• src/server.ts:56-69 (registration)

  The registration of the 'get_mappings' tool on the MCP server, including description, input schema, and handler invocation.

  server.tool(
    "get_mappings",
    "Get field mappings for a specific Elasticsearch index",
    {
      index: z
        .string()
        .trim()
        .min(1, "Index name is required")
        .describe("Name of the Elasticsearch index to get mappings for"),
    },
    async ({ index }) => {
      return await getMappings(esClient, index);
    }
  );

• src/server.ts:60-65 (schema)

  Zod schema for the input parameter 'index' of the 'get_mappings' tool.

    index: z
      .string()
      .trim()
      .min(1, "Index name is required")
      .describe("Name of the Elasticsearch index to get mappings for"),
  },