API Development and Integration

Chapter 14: Production API Best Practices

14.1 Production Considerations

Production APIs require monitoring, logging, and proper error handling.

// Request logging
const morgan = require('morgan');
app.use(morgan('combined'));

// Error tracking
const Sentry = require('@sentry/node');
Sentry.init({ dsn: process.env.SENTRY_DSN });

app.use(Sentry.Handlers.requestHandler());
app.use(Sentry.Handlers.errorHandler());

// Health check endpoint
app.get('/health', async (req, res) => {
    const health = {
        status: 'ok',
        timestamp: Date.now(),
        uptime: process.uptime(),
        database: await checkDatabase(),
        redis: await checkRedis()
    };
    
    const statusCode = health.database && health.redis ? 200 : 503;
    res.status(statusCode).json(health);
});

14.2 API Monitoring

// Track API metrics
const prometheus = require('prom-client');

const httpRequestDuration = new prometheus.Histogram({
    name: 'http_request_duration_seconds',
    help: 'Duration of HTTP requests',
    labelNames: ['method', 'route', 'status']
});

app.use((req, res, next) => {
    const start = Date.now();
    res.on('finish', () => {
        const duration = (Date.now() - start) / 1000;
        httpRequestDuration.observe({
            method: req.method,
            route: req.route?.path || req.path,
            status: res.statusCode
        }, duration);
    });
    next();
});

14.3 Rate Limiting

// Per-user rate limiting
const rateLimit = require('express-rate-limit');
const RedisStore = require('rate-limit-redis');
const redis = require('redis');

const limiter = rateLimit({
    store: new RedisStore({
        client: redis.createClient()
    }),
    windowMs: 15 * 60 * 1000,
    max: async (req) => {
        // Different limits for different users
        const user = await getUserFromToken(req);
        return user?.isPremium ? 1000 : 100;
    },
    keyGenerator: (req) => req.user?.id || req.ip
});

14.4 API Documentation in Production

// Keep documentation updated
// Use automated tools to generate docs from code
// Include examples and error responses
// Version your documentation with your API

Conclusion

Master API development to create robust, secure, and scalable APIs.