Async Client

HTTPX offers a standard synchronous API by default, but also gives youthe option of an async client if you need it.

Async is a concurrency model that is far more efficient than multi-threading,and can provide significant performance benefits and enable the use oflong-lived network connections such as WebSockets.

If you’re working with an async web framework then you’ll also want to use anasync client for sending outgoing HTTP requests.

Making Async requests

To make asynchronous requests, you’ll need an AsyncClient.

>>> client = httpx.AsyncClient()
>>> r = await client.get('https://www.example.com/')

API Differences

If you’re using streaming responses then there are a few bits of API thatuse async methods:

>>> client = httpx.AsyncClient()
>>> r = await client.get('https://www.example.com/', stream=True)
>>> try:
>>>     async for chunk in r.stream():
>>>         ...
>>> finally:
>>>     await r.close()

The async response methods are:

• .read()
• .stream()
• .raw()
• .close()

If you’re making parallel requests, then you’ll also need to use an async API:

>>> client = httpx.AsyncClient()
>>> async with client.parallel() as parallel:
>>>     pending_one = parallel.get('https://example.com/1')
>>>     pending_two = parallel.get('https://example.com/2')
>>>     response_one = await pending_one.get_response()
>>>     response_two = await pending_two.get_response()

The async parallel methods are:

• .parallel() Used as an “async with” context manager.
• .get_response()
• .next_response()