Overview

HTTPX 0.20, released on August 28, 2021, improves HTTP/2 support with request multiplexing and refines the async API.

Main Features

HTTP/2 multiplexing

HTTP/2 multiplexing sends multiple requests simultaneously over a single TCP connection, reducing latency and improving throughput for multiple API calls.

python 
import httpx
import asyncio

async def parallel_requests():
    async with httpx.AsyncClient(http2=True) as client:
        # Multiplexing: simultaneous requests on one connection
        tasks = [
            client.get('https://httpbin.org/get'),
            client.get('https://httpbin.org/headers'),
            client.get('https://httpbin.org/ip'),
        ]
        responses = await asyncio.gather(*tasks)
        for r in responses:
            print(f'{r.url} -> {r.status_code} [{r.http_version}]')

# asyncio.run(parallel_requests())

Improved async API

The async API has been refined with better connection lifecycle management, granular timeout support, and simplified ASGI framework integration.

python 
import httpx

# Synchronous client with granular timeouts
timeout = httpx.Timeout(
    connect=5.0,
    read=10.0,
    write=5.0,
    pool=2.0,
)

with httpx.Client(timeout=timeout) as client:
    r = client.get('https://httpbin.org/get')
    print(f'Status: {r.status_code}')
    print(f'HTTP version: {r.http_version}')

Sources