feat: allow es8 server version

#50

Author: nathanhuglo

index.ts

@@ -40,6 +40,12 @@ const ConfigSchema = z
       .string()
       .optional()
       .describe("Path to custom CA certificate for Elasticsearch"),
+
+    version: z
+      .string()
+      .optional()
+      .transform((val) => (["8", "9"].includes(val || "") ? val : "9"))
+      .describe("Elasticsearch version (8, or 9)"),
   })
   .refine(
     (data) => {
@@ -74,7 +80,7 @@ export async function createElasticsearchMcpServer(
   config: ElasticsearchConfig
 ) {
   const validatedConfig = ConfigSchema.parse(config);
-  const { url, apiKey, username, password, caCert } = validatedConfig;
+  const { url, apiKey, username, password, caCert, version } = validatedConfig;
 
   const clientOptions: ClientOptions = {
     node: url,
@@ -101,6 +107,16 @@ export async function createElasticsearchMcpServer(
     }
   }
 
+  // Add version-specific configuration
+  if (version === "8") {
+    clientOptions.maxRetries = 5;
+    clientOptions.requestTimeout = 30000;
+    clientOptions.headers = {
+      accept: "application/vnd.elasticsearch+json;compatible-with=8",
+      "content-type": "application/vnd.elasticsearch+json;compatible-with=8",
+    };
+  }
+
   const esClient = new Client(clientOptions);
 
   const server = new McpServer({
@@ -119,11 +135,11 @@ export async function createElasticsearchMcpServer(
         .min(1, "Index pattern is required")
         .describe("Index pattern of Elasticsearch indices to list"),
     },
-    async ( {indexPattern} ) => {
+    async ({ indexPattern }) => {
       try {
-        const response = await esClient.cat.indices({ 
-          index: indexPattern, 
-          format: "json" 
+        const response = await esClient.cat.indices({
+          index: indexPattern,
+          format: "json",
         });
 
         const indicesInfo = response.map((index) => ({
@@ -417,6 +433,7 @@ const config: ElasticsearchConfig = {
   username: process.env.ES_USERNAME || "",
   password: process.env.ES_PASSWORD || "",
   caCert: process.env.ES_CA_CERT || "",
+  version: process.env.ES_VERSION || "",
 };
 
 async function main() {