# Async Client

HTTPX offers a standard synchronous API by default, but also gives you
the 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 of
long-lived network connections such as WebSockets.

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

## Making Async requests

To make asynchronous requests, you'll need an `AsyncClient`.

```python
>>> 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 that
use async methods:

```python
>>> 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:

```python
>>> 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()`