diff --git a/src/generator/env-file.ts b/src/generator/env-file.ts
index d1cc591..1b26c64 100644
--- a/src/generator/env-file.ts
+++ b/src/generator/env-file.ts
@@ -19,6 +19,9 @@ export function generateEnvExample(
 # Server configuration
 PORT=3000
 LOG_LEVEL=info
+# If you have a server outside the servers list from OpenAPI, define it here.
+# Otherwise, omit this.
+API_BASE_URL=your_api_base_url_here
 
 `;
 
diff --git a/src/generator/server-code.ts b/src/generator/server-code.ts
index 6b6a447..a4d8e7a 100644
--- a/src/generator/server-code.ts
+++ b/src/generator/server-code.ts
@@ -130,7 +130,8 @@ interface McpToolDefinition {
  */
 export const SERVER_NAME = "${serverName}";
 export const SERVER_VERSION = "${serverVersion}";
-export const API_BASE_URL = "${determinedBaseUrl || ''}";
+// Base URL for the API, can be set via environment variable or determined from OpenAPI spec
+export const API_BASE_URL = process.env.API_BASE_URL || "${determinedBaseUrl || ''}";
 
 /**
  * MCP Server instance