fIx: smaller nits

backend/src/index.ts

@@ -0,0 +1,102 @@
+/**
+ * Backend API: Layered architecture for scalability and maintainability.
+ * 
+ * ## Architecture Layers
+ * 
+ * ### Controllers (routes/)
+ * - Handle HTTP requests and responses
+ * - Validate input and format output
+ * - Call services for business logic
+ * 
+ * ### Services (services/)
+ * - Implement business logic
+ * - Coordinate between controllers and repositories
+ * - Handle validation and transformation
+ * 
+ * ### Repositories (repositories/)
+ * - Data access layer
+ * - Interact with databases or external APIs
+ * - Return domain models
+ * 
+ * ### Models (models/)
+ * - Data structures and types
+ * - Validation schemas
+ * 
+ * ### Middleware (middleware/)
+ * - Request validation
+ * - Authentication/authorization
+ * - Rate limiting
+ * - Error handling
+ * 
+ * ## Adding New Endpoints
+ * 
+ * 1. Define the model in `models/`
+ * 2. Implement repository logic in `repositories/`
+ * 3. Implement service logic in `services/`
+ * 4. Create controller in `routes/`
+ * 5. Register route in `index.ts`
+ */
+
+import express from 'express'
+import cors from 'cors'
+
+// ---------------------------------------------------------------------------
+// Configuration
+// ---------------------------------------------------------------------------
+
+const PORT = Number(process.env.PORT) || 8080
+const CORS_ORIGIN = process.env.CORS_ORIGIN || 'http://localhost:3000'
+
+// ---------------------------------------------------------------------------
+// Express App Setup
+// ---------------------------------------------------------------------------
+
+const app = express()
+
+app.use(cors({ origin: CORS_ORIGIN }))
+app.use(express.json())
+
+// ---------------------------------------------------------------------------
+// Agent Routes
+// ---------------------------------------------------------------------------
+
+import { handleAgentRequest, handleAgentStreamRequest } from './routes/agentRoutes.js'
+
+/** POST /api/agent - Run AI agent */
+app.post('/api/agent', handleAgentRequest)
+
+/** POST /api/agent/stream - Stream AI agent response */
+app.post('/api/agent/stream', handleAgentStreamRequest)
+
+// ---------------------------------------------------------------------------
+// Health Check Endpoint
+// ---------------------------------------------------------------------------
+
+/** GET /health - Health check for Docker / orchestration */
+app.get('/health', (req, res) => {
+  res.status(200).json({ ok: true, timestamp: Date.now() })
+})
+
+// ---------------------------------------------------------------------------
+// Error Handling Middleware
+// ---------------------------------------------------------------------------
+
+/** Global error handler for consistent error responses */
+app.use((err: Error, req: express.Request, res: express.Response, next: express.NextFunction) => {
+  console.error('Error:', err)
+  res.status(500).json({ error: err.message ?? 'Internal server error' })
+})
+
+// ---------------------------------------------------------------------------
+// Start Server
+// ---------------------------------------------------------------------------
+
+app.listen(PORT, '0.0.0.0', () => {
+  console.log(`Backend listening on port ${PORT} (CORS: ${CORS_ORIGIN})`)
+})
+
+// ---------------------------------------------------------------------------
+// Export for testing
+// ---------------------------------------------------------------------------
+
+export default app