Build a Python Tool to Find All API Endpoints on a Website

import re
import requests
from urllib.parse import urljoin, urlparse
from collections import deque

def find_api_endpoints(base_url, max_pages=10):
    visited = set()
    queue = deque([base_url])
    api_endpoints = set()
    
    api_patterns = [
        r'/api/[a-zA-Z0-9_/-]+',
        r'/v[0-9]+/[a-zA-Z0-9_/-]+',
        r'/[a-zA-Z0-9_-]+\.json',
        r'/[a-zA-Z0-9_-]+/api/'
    ]
    
    while queue and len(visited) < max_pages:
        url = queue.popleft()
        if url in visited:
            continue
        visited.add(url)
        
        try:
            response = requests.get(url, timeout=5)
            if response.status_code != 200:
                continue
                
            # Search for API patterns in HTML/JS content
            for pattern in api_patterns:
                matches = re.findall(pattern, response.text)
                for match in matches:
                    full_url = urljoin(base_url, match)
                    parsed = urlparse(full_url)
                    if parsed.netloc == urlparse(base_url).netloc:
                        api_endpoints.add(full_url)
            
            # Find more links to crawl
            links = re.findall(r'href="([^"]+)"', response.text)
            for link in links:
                full_url = urljoin(base_url, link)
                parsed = urlparse(full_url)
                if parsed.netloc == urlparse(base_url).netloc:
                    queue.append(full_url)
                    
        except requests.RequestException:
            continue
    
    return sorted(api_endpoints)

if __name__ == "__main__":
    endpoints = find_api_endpoints("https://jsonplaceholder.typicode.com")
    for ep in endpoints:
        print(ep)