---
title: "Request API Security Best Practices"
description: "Get secure API implementations with proper authentication and validation"
category: "tips-tricks"
tags: ["api", "security", "authentication", "validation", "jwt"]
tech_stack: ["any"]
---

Building secure APIs requires a solid approach with multiple layers of protection. This guide walks you through some key security practices, such as authentication, input validation, rate limiting, and CORS configuration, all aimed at shielding your API from common vulnerabilities and attacks.

### 1. Implement JWT Authentication
Start by using the `jsonwebtoken` library to create and verify tokens. This helps you ensure that only authorized users access your API.

```javascript
const jwt = require('jsonwebtoken');
const token = jwt.sign({ userId: '123' }, 'your_secret_key', { expiresIn: '1h' });
```

### 2. Validate Input
Next, validate incoming data with a library like `express-validator`. This step is crucial for sanitizing inputs and preventing unwanted injections.

```javascript
const { body, validationResult } = require('express-validator');
app.post('/api/data', [
    body('email').isEmail(),
    body('password').isLength({ min: 5 })
], (req, res) => {
    const errors = validationResult(req);
    if (!errors.isEmpty()) {
        return res.status(400).json({ errors: errors.array() });
    }
    // Process data
});
```

### 3. Implement Rate Limiting
To protect against abuse, apply rate limiting using the `express-rate-limit` package. This helps you control the number of requests a user can make in a given timeframe.

```javascript
const rateLimit = require('express-rate-limit');
const limiter = rateLimit({ windowMs: 15 * 60 * 1000, max: 100 });
app.use(limiter);
```

### 4. Configure CORS
Use the `cors` middleware to restrict access to your API. This step is essential for allowing only trusted domains to communicate with your API.

```javascript
const cors = require('cors');
app.use(cors({ origin: 'https://yourdomain.com' }));
```

### 5. Sanitize Outputs
When sending data back to clients, sanitize it with a library like `DOMPurify`. This process ensures that the content is safe and free from harmful scripts.

```javascript
const cleanHTML = DOMPurify.sanitize(dirtyHTML);
```

### Why It Works
These practices boost your API's security. They make sure that only authenticated users can access resources, validate inputs to prevent injection attacks, and use rate limiting to safeguard against abuse. Make a habit of applying these strategies when developing or updating APIs.

### Quick Examples
- **Before**: No authentication, open to all requests.
- **After**: 
   ```javascript
   app.use(authMiddleware); // Protects routes with JWT
   ```
- **Before**: No input validation.
- **After**:
   ```javascript
   app.post('/api/register', [body('username').notEmpty()], (req, res) => { /* handle registration */ });
   ```

### Common Mistakes
Watch out for these common pitfalls:
- **Not using HTTPS**: Always serve your API over HTTPS to secure data during transmission.
- **Ignoring error handling**: Handle errors gracefully and avoid exposing stack traces.
- **Overly permissive CORS settings**: Restrict origins to trusted domains only.
- **Neglecting to update dependencies**: Regularly check and update your libraries to close security gaps. 

By following these guidelines, you can significantly enhance your API security and create a safer environment for your users.