REST API Tester

Test REST APIs with customizable headers, authentication, and request bodies. Use when debugging API endpoints, testing authentication flows, validating responses, or automating API checks. Supports GET, POST, PUT, DELETE, PATCH methods with JSON, form-data, and raw body formats. Ideal for developers testing webhooks, microservices, and third-party integrations.

API Tester

Test REST APIs with custom headers, auth, and request bodies.

When to Use

• Debugging API endpoints during development
• Testing authentication flows
• Validating webhook payloads
• Checking API response times
• Automating health checks
• Testing third-party integrations

Quick Start

Simple GET Request

python

import requests

def test_get(url, headers=None):
    """Test a GET endpoint"""
    try:
        response = requests.get(url, headers=headers, timeout=30)
        return {
            'status': response.status_code,
            'headers': dict(response.headers),
            'body': response.json() if response.headers.get('content-type', '').startswith('application/json') else response.text,
            'time': response.elapsed.total_seconds()
        }
    except Exception as e:
        return {'error': str(e)}

# Usage
test_get('https://api.github.com/users/octocat')

POST with JSON Body

python

def test_post(url, data, headers=None):
    """Test POST endpoint with JSON body"""
    default_headers = {'Content-Type': 'application/json'}
    if headers:
        default_headers.update(headers)
    
    try:
        response = requests.post(
            url, 
            json=data, 
            headers=default_headers,
            timeout=30
        )
        return {
            'status': response.status_code,
            'body': response.json() if response.headers.get('content-type', '').startswith('application/json') else response.text
        }
    except Exception as e:
        return {'error': str(e)}

# Usage
test_post('https://httpbin.org/post', {'key': 'value'})

Test with Authentication

python

def test_with_auth(url, token=None, username=None, password=None):
    """Test API with Bearer token or Basic auth"""
    headers = {}
    
    if token:
        headers['Authorization'] = f'Bearer {token}'
    elif username and password:
        import base64
        credentials = base64.b64encode(f'{username}:{password}'.encode()).decode()
        headers['Authorization'] = f'Basic {credentials}'
    
    return test_get(url, headers)

# Bearer token
test_with_auth('https://api.example.com/data', token='your_token_here')

# Basic auth
test_with_auth('https://api.example.com/data', username='admin', password='secret')

Full API Test Suite

python

def comprehensive_api_test(base_url, endpoints):
    """Test multiple endpoints"""
    results = {}
    
    for endpoint, config in endpoints.items():
        url = f"{base_url}{config['path']}"
        method = config.get('method', 'GET')
        headers = config.get('headers', {})
        data = config.get('data')
        
        try:
            if method == 'GET':
                response = requests.get(url, headers=headers, timeout=30)
            elif method == 'POST':
                response = requests.post(url, json=data, headers=headers, timeout=30)
            elif method == 'PUT':
                response = requests.put(url, json=data, headers=headers, timeout=30)
            elif method == 'DELETE':
                response = requests.delete(url, headers=headers, timeout=30)
            
            results[endpoint] = {
                'status': response.status_code,
                'success': 200 <= response.status_code < 300,
                'time': response.elapsed.total_seconds()
            }
        except Exception as e:
            results[endpoint] = {'error': str(e), 'success': False}
    
    return results

# Usage
endpoints = {
    'health': {'path': '/health', 'method': 'GET'},
    'create_user': {'path': '/users', 'method': 'POST', 'data': {'name': 'Test'}},
    'get_user': {'path': '/users/1', 'method': 'GET'}
}

comprehensive_api_test('https://api.example.com', endpoints)

Common Testing Scenarios

Webhook Testing

python

from flask import Flask, request

def create_webhook_listener(port=5000):
    """Create local webhook receiver for testing"""
    app = Flask(__name__)
    received_data = []
    
    @app.route('/webhook', methods=['POST'])
    def webhook():
        data = request.json
        received_data.append(data)
        print(f"Received webhook: {data}")
        return {'status': 'ok'}
    
    @app.route('/received', methods=['GET'])
    def get_received():
        return {'data': received_data}
    
    return app

# Run: app.run(port=5000)
# Use ngrok to expose: ngrok http 5000

Performance Testing

python

import time

def test_api_performance(url, iterations=10):
    """Test API response times"""
    times = []
    
    for _ in range(iterations):
        start = time.time()
        requests.get(url, timeout=30)
        times.append(time.time() - start)
    
    return {
        'min': min(times),
        'max': max(times),
        'avg': sum(times) / len(times),
        'times': times
    }

Response Validation

python

def validate_response(response, expected_status=200, required_fields=None):
    """Validate API response structure"""
    errors = []
    
    if response.get('status') != expected_status:
        errors.append(f"Expected status {expected_status}, got {response.get('status')}")
    
    body = response.get('body', {})
    if required_fields:
        for field in required_fields:
            if field not in body:
                errors.append(f"Missing required field: {field}")
    
    return {
        'valid': len(errors) == 0,
        'errors': errors
    }

Dependencies

bash

pip install requests flask