diff --git a/frontend/src/config/api.ts b/frontend/src/config/api.ts
new file mode 100644
index 00000000..70fbcd08
--- /dev/null
+++ b/frontend/src/config/api.ts
@@ -0,0 +1,24 @@
+// API Configuration
+// Single source of truth for backend URL
+
+const getBackendUrl = (): string => {
+  const url = process.env.EXPO_PUBLIC_BACKEND_URL;
+  
+  if (!url) {
+    console.error('⚠️ EXPO_PUBLIC_BACKEND_URL not set! Using fallback.');
+    return 'http://localhost:8001';
+  }
+  
+  console.log('✅ Backend URL:', url);
+  return url;
+};
+
+export const API_BASE_URL = getBackendUrl();
+
+export const API_ENDPOINTS = {
+  AUTH_SIGNUP: `${API_BASE_URL}/api/auth/signup`,
+  AUTH_SIGNIN: `${API_BASE_URL}/api/auth/signin`,
+  AUTH_USER: (userId: string) => `${API_BASE_URL}/api/auth/user/${userId}`,
+  VERIFY_TURNSTILE: `${API_BASE_URL}/api/verify-turnstile`,
+  BALANCE: `${API_BASE_URL}/api/blockchain/balance`,
+};