diff --git a/nextjs-app/lib/api.ts b/nextjs-app/lib/api.ts
index 591a1da..3b28132 100644
--- a/nextjs-app/lib/api.ts
+++ b/nextjs-app/lib/api.ts
@@ -20,7 +20,11 @@ import type {
 // Configuration
 // ============================================================================
 
-const API_BASE_URL = process.env.NEXT_PUBLIC_API_URL || '/api';
+// Use FASTAPI_URL for server-side requests (internal Docker network)
+// Use NEXT_PUBLIC_API_URL for client-side requests (browser)
+const API_BASE_URL = typeof window === 'undefined'
+  ? (process.env.FASTAPI_URL || process.env.NEXT_PUBLIC_API_URL || '/api')
+  : (process.env.NEXT_PUBLIC_API_URL || '/api');
 
 // Cache configuration for server-side fetching (Next.js revalidate)
 export const CACHE_DURATION = {