feat: add environment variable validation and update documentation

backend/.env.example

@@ -1,21 +1,15 @@
-# Backend Environment Variables
-# Copy this to .env and fill in your actual values
-
-# Supabase Configuration (get from https://app.supabase.com → Project Settings → API)
+# Supabase Configuration
 SUPABASE_URL=https://your-project-id.supabase.co
-SUPABASE_ANON_KEY=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9...
-SUPABASE_SERVICE_ROLE_KEY=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9...
+SUPABASE_ANON_KEY=your-anon-key
+SUPABASE_SERVICE_ROLE_KEY=your-service-role-key
 
-# HuggingFace API Token (optional - get from https://huggingface.co/settings/tokens)
-# If not provided, crisis detection will use keyword-based fallback
+# HuggingFace API Token (Optional)
 HUGGINGFACE_API_TOKEN=hf_YourTokenHere
 
-# Frontend URL (for CORS whitelist)
-FRONTEND_URL=http://localhost:3000
-
 # Server Configuration
 PORT=3001
+FRONTEND_URL=http://localhost:3000
 
-# Rate Limiting (optional - defaults shown)
+# Rate Limiting
 RATE_LIMIT_WINDOW_MS=900000
 RATE_LIMIT_MAX_REQUESTS=100

backend/package.json

@@ -9,7 +9,12 @@
     "start": "node dist/index.js",
     "setup-db": "ts-node src/scripts/setupDatabase.ts"
   },
-  "keywords": ["mental-health", "websocket", "express", "crisis-detection"],
+  "keywords": [
+    "mental-health",
+    "websocket",
+    "express",
+    "crisis-detection"
+  ],
   "author": "OpenMindWell Contributors",
   "license": "MIT",
   "dependencies": {
@@ -19,7 +24,8 @@
     "express": "^4.18.2",
     "express-rate-limit": "^7.1.5",
     "helmet": "^7.1.0",
-    "ws": "^8.16.0"
+    "ws": "^8.16.0",
+    "zod": "^4.3.6"
   },
   "devDependencies": {
     "@types/cors": "^2.8.17",

backend/src/config/env.ts

@@ -0,0 +1,32 @@
+import { z } from 'zod';
+import dotenv from 'dotenv';
+
+dotenv.config();
+
+const envSchema = z.object({
+  // Supabase Configuration
+  SUPABASE_URL: z.string().url(),
+  SUPABASE_ANON_KEY: z.string().min(1),
+  SUPABASE_SERVICE_ROLE_KEY: z.string().min(1),
+
+  // HuggingFace API Token (Optional)
+  HUGGINGFACE_API_TOKEN: z.string().optional(),
+
+  // Server Configuration
+  FRONTEND_URL: z.string().url().default('http://localhost:3000'),
+  PORT: z.coerce.number().default(3001),
+
+  // Rate Limiting
+  RATE_LIMIT_WINDOW_MS: z.coerce.number().default(900000),
+  RATE_LIMIT_MAX_REQUESTS: z.coerce.number().default(100),
+});
+
+const _env = envSchema.safeParse(process.env);
+
+if (!_env.success) {
+  console.error('Invalid environment variables:');
+  console.error(JSON.stringify(_env.error.format(), null, 4));
+  process.exit(1);
+}
+
+export const env = _env.data;

backend/src/config/index.ts

@@ -1,60 +1,22 @@
-import dotenv from 'dotenv';
+import { env } from './env';
 
-dotenv.config();
-
-interface Config {
+const config = {
   supabase: {
-    url: string;
-    anonKey: string;
-    serviceRoleKey: string;
-  };
-  huggingface: {
-    apiToken?: string;
-  };
-  server: {
-    port: number;
-    frontendUrl: string;
-  };
-  rateLimit: {
-    windowMs: number;
-    maxRequests: number;
-  };
-}
-
-const config: Config = {
-  supabase: {
-    url: process.env.SUPABASE_URL || '',
-    anonKey: process.env.SUPABASE_ANON_KEY || '',
-    serviceRoleKey: process.env.SUPABASE_SERVICE_ROLE_KEY || '',
+    url: env.SUPABASE_URL,
+    anonKey: env.SUPABASE_ANON_KEY,
+    serviceRoleKey: env.SUPABASE_SERVICE_ROLE_KEY,
   },
   huggingface: {
-    apiToken: process.env.HUGGINGFACE_API_TOKEN,
+    apiToken: env.HUGGINGFACE_API_TOKEN,
   },
   server: {
-    port: parseInt(process.env.PORT || '3001', 10),
-    frontendUrl: process.env.FRONTEND_URL || 'http://localhost:3000',
+    port: env.PORT,
+    frontendUrl: env.FRONTEND_URL,
   },
   rateLimit: {
-    windowMs: parseInt(process.env.RATE_LIMIT_WINDOW_MS || '900000', 10),
-    maxRequests: parseInt(process.env.RATE_LIMIT_MAX_REQUESTS || '100', 10),
+    windowMs: env.RATE_LIMIT_WINDOW_MS,
+    maxRequests: env.RATE_LIMIT_MAX_REQUESTS,
   },
 };
 
-// Validation
-const requiredEnvVars = [
-  'SUPABASE_URL',
-  'SUPABASE_ANON_KEY',
-  'SUPABASE_SERVICE_ROLE_KEY',
-  'FRONTEND_URL',
-];
-
-const missingVars = requiredEnvVars.filter((varName) => !process.env[varName]);
-
-if (missingVars.length > 0) {
-  throw new Error(
-    `Missing required environment variables: ${missingVars.join(', ')}\n` +
-      'Please check your .env file and ensure all required variables are set.'
-  );
-}
-
 export default config;