diff --git a/frontend/.env.example b/frontend/.env.example
new file mode 100644
index 0000000..1406906
--- /dev/null
+++ b/frontend/.env.example
@@ -0,0 +1,4 @@
+# Backend API base URL
+# Override for deployed/staging environments (e.g., PythonAnywhere).
+# Defaults to http://127.0.0.1:5000/ for local development.
+NEXT_PUBLIC_API_BASE_URL=http://127.0.0.1:5000/
diff --git a/frontend/.gitignore b/frontend/.gitignore
index 5ef6a52..3957fb3 100644
--- a/frontend/.gitignore
+++ b/frontend/.gitignore
@@ -31,7 +31,11 @@ yarn-error.log*
 .pnpm-debug.log*
 
 # env files (can opt-in for committing if needed)
-.env*
+.env.example
+.env.local
+.env.development
+.env.production
+.env
 
 # vercel
 .vercel
diff --git a/frontend/services/api.ts b/frontend/services/api.ts
index 006d226..7244e38 100644
--- a/frontend/services/api.ts
+++ b/frontend/services/api.ts
@@ -5,7 +5,8 @@ import {
   SDGClassificationResponse,
 } from "@/types/main";
 
-const API_BASE_URL = "http://127.0.0.1:5000/";
+const API_BASE_URL =
+  process.env.NEXT_PUBLIC_API_BASE_URL ?? "http://127.0.0.1:5000/";
 
 const apiClient = axios.create({
   baseURL: API_BASE_URL,