Overview

HTTPX 0.22, released on January 27, 2022, introduces event hooks for request interception and improves the custom transport API.

Main Features

Event hooks

Event hooks allow intercepting requests and responses to add logging, authentication, or transformations without modifying client code.

python 
import httpx

def log_request(request):
    print(f'>> {request.method} {request.url}')

def log_response(response):
    print(f'<< {response.status_code}')

client = httpx.Client(
    event_hooks={
        'request': [log_request],
        'response': [log_response],
    }
)
response = client.get('https://httpbin.org/get')

Transport API

The transport API allows creating custom backends for mocking requests or using alternative protocols.

python 
import httpx

# Custom transport for testing
def mock_transport(request):
    return httpx.Response(
        200,
        json={'status': 'ok'},
    )

client = httpx.Client(
    transport=httpx.MockTransport(mock_transport)
)
response = client.get('https://api.example.com/health')
print(response.json())  # {'status': 'ok'}

Sources