Elasticsearch MCP Server

Instructions

Implementation Reference

• index.ts:187-227 (handler)

  The handler function for the get_mappings tool. It fetches the mappings for the specified Elasticsearch index using esClient.indices.getMapping and returns a formatted text response with the mappings or an error message.

  async ({ index }) => {
    console.error("[DEBUG] get_mappings tool called", index);
    try {
      const mappingResponse = await esClient.indices.getMapping({
        index,
      });
  
      return {
        content: [
          {
            type: "text" as const,
            text: `Mappings for index: ${index}`,
          },
          {
            type: "text" as const,
            text: `Mappings for index ${index}: ${JSON.stringify(
              mappingResponse[index]?.mappings || {},
              null,
              2
            )}`,
          },
        ],
      };
    } catch (error) {
      console.error(
        `Failed to get mappings: ${
          error instanceof Error ? error.message : String(error)
        }`
      );
      return {
        content: [
          {
            type: "text" as const,
            text: `Error: ${
              error instanceof Error ? error.message : String(error)
            }`,
          },
        ],
      };
    }
  }

• index.ts:180-186 (schema)

  Input schema for the get_mappings tool, which validates that the 'index' parameter is a non-empty trimmed string.

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

• index.ts:178-228 (registration)

  Registration of the get_mappings tool using server.tool(), including name, description, input schema, and handler function.

    "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 }) => {
      console.error("[DEBUG] get_mappings tool called", index);
      try {
        const mappingResponse = await esClient.indices.getMapping({
          index,
        });
  
        return {
          content: [
            {
              type: "text" as const,
              text: `Mappings for index: ${index}`,
            },
            {
              type: "text" as const,
              text: `Mappings for index ${index}: ${JSON.stringify(
                mappingResponse[index]?.mappings || {},
                null,
                2
              )}`,
            },
          ],
        };
      } catch (error) {
        console.error(
          `Failed to get mappings: ${
            error instanceof Error ? error.message : String(error)
          }`
        );
        return {
          content: [
            {
              type: "text" as const,
              text: `Error: ${
                error instanceof Error ? error.message : String(error)
              }`,
            },
          ],
        };
      }
    }
  );