refactor: update VITE_API_URL configuration and enhance path handling in API service

.env.example

@@ -34,6 +34,6 @@ DEBOUNCE_MS=2000              # Debounce delay for frontend input
 # SEQ_API_KEY=your-seq-api-key
 
 # Development Overrides (used in docker-compose.dev.yml)
-# VITE_API_URL=http://localhost:5172/api
+# VITE_API_URL=http://localhost:5172
 # VITE_API_KEY=frontend-dev-key
 # VITE_DEBOUNCE_MS=1000

docs/CONFIGURATION.md

@@ -268,7 +268,7 @@ The frontend is configured via environment variables, typically stored in `src/f
 
 ```env
 VITE_API_KEY=frontend-dev-key
-VITE_API_URL=http://localhost:5172/geoip-ui/api
+VITE_API_URL=http://localhost:5172/geoip-ui
 VITE_DEBOUNCE_MS=2000
 ```
 
@@ -282,12 +282,12 @@ VITE_DEBOUNCE_MS=2000
 
 **`VITE_API_URL`**
 
-- **Purpose**: Full URL to the backend API (including base path and `/api` suffix)
+- **Purpose**: Base URL to the backend server
 - **Format**: HTTP/HTTPS URL
 - **Required**: Yes
-- **Development Example**: `http://localhost:5172/geoip-ui/api`
+- **Development Example**: `http://localhost:5172/geoip-ui`
-- **Production Example**: `https://your-domain.com/geoip-ui/api`
+- **Production Example**: `https://your-domain.com/geoip-ui`
-- **Note**: Must match backend's `PORT` and `BASE_PATH` configuration
+- **Note**: Must match backend's `PORT` and `BASE_PATH` configuration.
 
 **`VITE_DEBOUNCE_MS`**
 
@@ -332,7 +332,7 @@ VITE_DEBOUNCE_MS=2000
 
    ```env
    VITE_API_KEY=frontend-dev-key
-   VITE_API_URL=http://localhost:5172/geoip-ui/api
+   VITE_API_URL=http://localhost:5172/geoip-ui
    VITE_DEBOUNCE_MS=2000
    ```
 
@@ -380,7 +380,7 @@ DEBOUNCE_MS=2000
 
 ```env
 VITE_API_KEY=<same-as-backend-FRONTEND_API_KEY>
-VITE_API_URL=https://your-domain.com/api
+VITE_API_URL=https://your-domain.com
 VITE_DEBOUNCE_MS=2000
 ```
 

src/frontend/.env

@@ -1,5 +1,5 @@
 # Frontend Environment Variables for Local Development
 VITE_API_KEY=frontend-dev-key
-VITE_API_URL=http://localhost:5172/api
+VITE_API_URL=http://localhost:5172
 VITE_DEBOUNCE_MS=2000
 VITE_BASE_PATH=/

src/frontend/src/services/api.ts

@@ -8,8 +8,23 @@ import {
   OverviewResponse,
 } from '../types';
 
+/**
+ * Combines base URL and path, ensuring proper slash handling
+ * @param baseUrl - Base URL (e.g., 'http://localhost:5172' or 'http://localhost:5172/')
+ * @param path - Path to append (e.g., '/api' or 'api')
+ * @returns Combined URL path
+ */
+const pathCombine = (baseUrl: string, path: string): string => {
+  const trimmedBase = baseUrl.replace(/\/+$/, ''); // Remove trailing slashes
+  const trimmedPath = path.replace(/^\/+/, ''); // Remove leading slashes
+  return `${trimmedBase}/${trimmedPath}`;
+};
+
+const isDevelopment = import.meta.env.MODE === 'development';
 const API_KEY = import.meta.env.VITE_API_KEY || 'frontend-default-key';
-const BASE_URL = import.meta.env.VITE_API_URL || '/api';
+const BASE_URL = isDevelopment
+  ? pathCombine(import.meta.env.VITE_API_URL, '/api')
+  : '/api';
 
 const apiClient = axios.create({
   baseURL: BASE_URL,