A2jax

A secure, lightweight JavaScript library for making HTTP requests with built-in security features and flexible configuration options.

Features

• 🔒 Multi-level Security: Three security levels (low, medium, high) with automatic input sanitization
• 🛡️ CSRF Protection: Built-in CSRF token handling for secure requests
• ⚡ Rate Limiting: Configurable request rate limiting to prevent abuse
• 🔑 API Key Support: Secure API key authentication for high-security applications
• ⏱️ Timeout Management: Configurable request timeouts with automatic handling
• 🌐 Base URL Support: Set a base URL for all requests
• 📝 Input Sanitization: Automatic sanitization of request data based on security level
• 🚫 Request Size Limits: Configurable limits to prevent oversized requests

Installation

npm install a2jax

Or include directly in your HTML:

<script src="https://cdn.jsdelivr.net/npm/a2jax@latest/dist/a2jax.min.js"></script>

Quick Start

// Basic usage with default medium security
const xhr = new A2jax();

// Make a GET request
xhr.get('/api/users')
    .then(response => {
        console.log('Users:', response.data);
    })
    .catch(error => {
        console.error('Error:', error);
    });

// Make a POST request
xhr.post('/api/users', {
    name: 'John Doe',
    email: '[email protected]'
})
    .then(response => {
        console.log('User created:', response.data);
    });

Configuration

Basic Configuration

const xhr = new A2jax({
    security: true,
    securityLevel: 'high',
    timeout: 15000,
    baseURL: 'https://api.example.com',
    apiKey: 'your-api-key-here'
});

Security Levels

| Level | Features | |-------|----------| | Low | Basic input sanitization, no CSRF protection, no rate limiting | | Medium (Default) | Input sanitization, CSRF protection, rate limiting (10 req/sec), SSL validation, 1MB request limit | | High | All medium features + enhanced rate limiting (5 req/sec), 512KB limit, API key requirement, session validation |

Configuration Methods

// Method 1: During initialization
const xhr = new A2jax({
    security: true,
    securityLevel: 'high',
    apiKey: 'your-api-key'
});

// Method 2: Using configuration methods
const xhr2 = new A2jax();
xhr2.setSecurity(true, 'medium')
    .setApiKey('your-api-key')
    .setBaseURL('https://api.example.com');

// Method 3: Static factory method
const xhr3 = A2jax.create({
    security: true,
    securityLevel: 'high',
    timeout: 20000
});

API Reference

GET Requests

// Basic GET request
xhr.get('/api/users')
    .then(response => console.log(response.data));

// GET with custom headers
xhr.get('/api/users/123', {
    headers: {
        'Authorization': 'Bearer your-token',
        'Accept': 'application/json'
    }
})
    .then(response => console.log(response.data));

// GET with query parameters
const params = new URLSearchParams({ include: 'profile,settings' });
xhr.get(`/api/users/123?${params}`)
    .then(response => console.log(response.data));

POST Requests

// Basic POST request
xhr.post('/api/users', {
    name: 'John Doe',
    email: '[email protected]',
    age: 30
})
    .then(response => console.log(response.data));

// POST with custom headers
xhr.post('/api/login', {
    username: 'johndoe',
    password: 'securepassword'
}, {
    headers: {
        'Content-Type': 'application/json',
        'X-Client-Version': '1.0.0'
    }
})
    .then(response => {
        localStorage.setItem('authToken', response.data.token);
    });

Advanced Usage

API Client Pattern

class APIClient {
    constructor(baseURL, apiKey) {
        this.client = new A2jax({
            security: true,
            securityLevel: 'high',
            baseURL: baseURL,
            apiKey: apiKey,
            timeout: 30000,
            defaultHeaders: {
                'Accept': 'application/json',
                'User-Agent': 'MyApp/1.0'
            }
        });
    }

    async getUsers() {
        try {
            const response = await this.client.get('/users');
            return response.data;
        } catch (error) {
            throw new Error(`Failed to fetch users: ${error.error}`);
        }
    }

    async createUser(userData) {
        try {
            const response = await this.client.post('/users', userData);
            return response.data;
        } catch (error) {
            if (error.status === 400) {
                throw new Error('Invalid user data provided');
            }
            throw new Error(`Failed to create user: ${error.error}`);
        }
    }
}

// Usage
const api = new APIClient('https://api.myapp.com', 'your-api-key');
const users = await api.getUsers();

Error Handling

async function handleAPICall() {
    try {
        const response = await xhr.post('/api/sensitive-data', {
            data: 'sensitive information'
        });
        
        console.log('Success:', response.data);
        
    } catch (error) {
        if (error.error === 'Rate limit exceeded. Please slow down your requests.') {
            console.warn('Too many requests, waiting before retry...');
            setTimeout(() => handleAPICall(), 2000);
            
        } else if (error.error === 'Request timeout') {
            console.error('Request timed out, check your connection');
            
        } else if (error.status === 413) {
            console.error('Request too large, reduce data size');
            
        } else if (error.status >= 500) {
            console.error('Server error, try again later');
            
        } else {
            console.error('Request failed:', error);
        }
    }
}

Retry with Exponential Backoff

async function retryRequest(url, data, maxRetries = 3) {
    const xhr = new A2jax({
        security: true,
        securityLevel: 'medium'
    });

    for (let attempt = 1; attempt <= maxRetries; attempt++) {
        try {
            const response = await xhr.post(url, data);
            return response;
            
        } catch (error) {
            if (attempt === maxRetries) {
                throw error;
            }
            
            // Wait with exponential backoff
            const delay = Math.pow(2, attempt) * 1000;
            await new Promise(resolve => setTimeout(resolve, delay));
        }
    }
}

Environment-Specific Configuration

Development Environment

const devXhr = new A2jax({
    security: true,
    securityLevel: 'low',
    baseURL: 'http://localhost:3000/api',
    timeout: 5000
});

Production Environment

const prodXhr = new A2jax({
    security: true,
    securityLevel: 'high',
    baseURL: 'https://secure-api.production.com',
    apiKey: process.env.API_KEY,
    timeout: 15000,
    defaultHeaders: {
        'X-App-Version': '2.1.0',
        'X-Client-ID': 'web-client'
    }
});

Common Patterns

Form Submission

async function submitContactForm(formData) {
    const xhr = new A2jax({
        security: true,
        securityLevel: 'medium'
    });

    try {
        const response = await xhr.post('/api/contact', {
            name: formData.name,
            email: formData.email,
            message: formData.message,
            timestamp: Date.now()
        });

        showNotification('Message sent successfully!', 'success');
        return response.data;

    } catch (error) {
        showNotification('Failed to send message. Please try again.', 'error');
        throw error;
    }
}

Loading Multiple Resources

async function loadUserDashboard(userId) {
    const xhr = new A2jax({
        security: true,
        securityLevel: 'high',
        apiKey: getAuthToken()
    });

    showLoadingSpinner(true);

    try {
        const [userResponse, statsResponse] = await Promise.all([
            xhr.get(`/api/users/${userId}`),
            xhr.get(`/api/users/${userId}/stats`)
        ]);

        updateUserProfile(userResponse.data);
        updateUserStats(statsResponse.data);

    } catch (error) {
        if (error.status === 401) {
            redirectToLogin();
        } else {
            showErrorMessage('Failed to load dashboard data');
        }
    } finally {
        showLoadingSpinner(false);
    }
}

Security Features

Input Sanitization

A2jax automatically sanitizes input data based on the configured security level, preventing XSS attacks and other malicious input.

CSRF Protection

Medium and high security levels include automatic CSRF token handling to prevent cross-site request forgery attacks.

Rate Limiting

Built-in rate limiting prevents abuse:

• Medium security: 10 requests per second
• High security: 5 requests per second

Request Size Limits

Configurable limits prevent oversized requests:

• Medium security: 1MB limit
• High security: 512KB limit

Browser Support

A2jax supports all modern browsers that support:

• Promises
• Fetch API or XMLHttpRequest
• ES6 features

Contributing

1. Fork the repository
2. Create your feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'Add some amazing feature')
4. Push to the branch (git push origin feature/amazing-feature)
5. Open a Pull Request

License

This project is licensed under the MIT License - see the LICENSE file for details.

Support

For support, please open an issue on GitHub or contact the maintainers.

A2jax - Secure HTTP requests made simple.