OAuth 2.0 Client Credentials for Server-to-Server API

import requests
import os

def get_oauth_token(token_url, client_id, client_secret, scope=None):
    """
    Retrieves an OAuth 2.0 access token using the Client Credentials flow.
    """
    headers = {
        'Content-Type': 'application/x-www-form-urlencoded'
    }
    data = {
        'grant_type': 'client_credentials',
        'client_id': client_id,
        'client_secret': client_secret
    }
    if scope:
        data['scope'] = scope

    try:
        response = requests.post(token_url, headers=headers, data=data)
        response.raise_for_status() # Raise an exception for HTTP errors
        token_data = response.json()
        return token_data.get('access_token')
    except requests.exceptions.RequestException as e:
        print(f"Error fetching OAuth token: {e}")
        return None

def make_authenticated_api_call(api_url, access_token):
    """
    Makes an API call with the obtained access token.
    """
    if not access_token:
        print("No access token available. Cannot make API call.")
        return None

    headers = {
        'Authorization': f'Bearer {access_token}',
        'Accept': 'application/json'
    }
    try:
        response = requests.get(api_url, headers=headers)
        response.raise_for_status()
        return response.json()
    except requests.exceptions.RequestException as e:
        print(f"Error making authenticated API call: {e}")
        return None

# Example Usage:
# TOKEN_URL = os.environ.get('OAUTH_TOKEN_URL', 'https://auth.example.com/oauth/token')
# CLIENT_ID = os.environ.get('OAUTH_CLIENT_ID', 'your_client_id')
# CLIENT_SECRET = os.environ.get('OAUTH_CLIENT_SECRET', 'your_client_secret')
# API_RESOURCE_URL = os.environ.get('API_RESOURCE_URL', 'https://api.example.com/protected_resource')
# SCOPE = 'read write' # Optional

# access_token = get_oauth_token(TOKEN_URL, CLIENT_ID, CLIENT_SECRET, SCOPE)

# if access_token:
#     print("Access Token:", access_token)
#     api_data = make_authenticated_api_call(API_RESOURCE_URL, access_token)
#     if api_data:
#         print("API Data:", api_data)
# else:
#     print("Failed to get access token.")