diff --git a/.gitignore b/.gitignore
index d59519f..6cad36e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -10,4 +10,5 @@
 .vscode
 .yarn
 node_modules
-config.json
\ No newline at end of file
+config.json
+data/
\ No newline at end of file
diff --git a/ews_client.ts b/ews_client.ts
index 5440120..dca9434 100644
--- a/ews_client.ts
+++ b/ews_client.ts
@@ -3,13 +3,18 @@ import fs from "node:fs";
 import https from "node:https";
 import { createRequire } from "node:module";
 import path from "node:path";
-import { fileURLToPath } from "node:url";
 import { promisify } from "node:util";
 import type { Email } from "./types/email.ts";
 import type { Folder } from "./types/folder.ts";
 import type { LoginConfig } from "./types/login_config.ts";
 
 let inMemoryPassword: string | null = null;
+let dataDir: string = "./data";
+
+export function initDataDir(dir: string): void {
+  dataDir = path.resolve(dir);
+  fs.mkdirSync(dataDir, { recursive: true });
+}
 
 export function setPassword(password: string): void {
   inMemoryPassword = password;
@@ -74,8 +79,7 @@ ${body}
 }
 
 function configFilePath(): string {
-  const dir = path.dirname(fileURLToPath(import.meta.url));
-  return path.join(dir, "config.json");
+  return path.join(dataDir, "config.json");
 }
 
 export function loadConfig(): LoginConfig {
diff --git a/main.ts b/main.ts
index bf53607..de1f50d 100644
--- a/main.ts
+++ b/main.ts
@@ -4,6 +4,7 @@ import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js"
 import { Command } from "commander";
 import crypto from "node:crypto";
 import http from "node:http";
+import { initDataDir } from "./ews_client.ts";
 import { registerAuthTools } from "./tools/auth.ts";
 import { registerEmailTools } from "./tools/email.ts";
 import { registerFolderTools } from "./tools/folders.ts";
@@ -17,11 +18,14 @@ const program = new Command()
     "SHA-256 hash of bearer token for HTTP transport auth",
   )
   .option("--host <host>", "HTTP host", "127.0.0.1")
-  .option("--port <port>", "HTTP port", "8000");
+  .option("--port <port>", "HTTP port", "8000")
+  .option("--data-dir <path>", "Data directory for config.json", "./data");
 
 program.parse(process.argv);
 const options = program.opts();
 
+initDataDir(options.dataDir);
+
 function buildServer(): McpServer {
   const server = new McpServer({
     name: "exchange-mcp",