# aiohttp-client-cache
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[](https://aiohttp-client-cache.readthedocs.io/en/latest/)
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[](https://pypi.org/project/aiohttp-client-cache)
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**aiohttp-client-cache** is an async persistent cache for [aiohttp](https://docs.aiohttp.org)
client requests, based on [requests-cache](https://github.com/reclosedev/requests-cache).
# Features
* **Ease of use:** Use as a [drop-in replacement](https://aiohttp-client-cache.readthedocs.io/en/latest/user_guide.html)
for `aiohttp.ClientSession`
* **Customization:** Works out of the box with little to no config, but with plenty of options
available for customizing cache
[expiration](https://aiohttp-client-cache.readthedocs.io/en/latest/user_guide.html#cache-expiration)
and other [behavior](https://aiohttp-client-cache.readthedocs.io/en/latest/user_guide.html#cache-options)
* **Persistence:** Includes several [storage backends](https://aiohttp-client-cache.readthedocs.io/en/latest/backends.html):
SQLite, DynamoDB, MongoDB, and Redis.
# Development Status
**This library is a work in progress!**
Breaking changes should be expected until a `1.0` release, so version pinning is recommended.
My goal for this library is to eventually have a similar (but not identical) feature set as
`requests-cache`, and also contribute new features from this library back to `requests-cache`.
If there is a feature you want, if you've discovered a bug, or if you have other general feedback, please
[create an issue](https://github.com/requests-cache/aiohttp-client-cache/issues/new/choose) for it!
# Quickstart
First, install with pip (python 3.7+ required):
```bash
pip install aiohttp-client-cache
```
## Basic Usage
Next, use [aiohttp_client_cache.CachedSession](https://aiohttp-client-cache.readthedocs.io/en/latest/modules/aiohttp_client_cache.session.html#aiohttp_client_cache.session.CachedSession)
in place of [aiohttp.ClientSession](https://docs.aiohttp.org/en/stable/client_reference.html#aiohttp.ClientSession).
To briefly demonstrate how to use it:
**Replace this:**
```python
from aiohttp import ClientSession
async with ClientSession() as session:
await session.get('http://httpbin.org/delay/1')
```
**With this:**
```python
from aiohttp_client_cache import CachedSession, SQLiteBackend
async with CachedSession(cache=SQLiteBackend('demo_cache')) as session:
await session.get('http://httpbin.org/delay/1')
```
The URL in this example adds a delay of 1 second, simulating a slow or rate-limited website.
With caching, the response will be fetched once, saved to `demo_cache.sqlite`, and subsequent
requests will return the cached response near-instantly.
## Configuration
Several options are available to customize caching behavior. This example demonstrates a few of them:
```python
# fmt: off
from aiohttp_client_cache import SQLiteBackend
cache = SQLiteBackend(
cache_name='~/.cache/aiohttp-requests.db', # For SQLite, this will be used as the filename
expire_after=60*60, # By default, cached responses expire in an hour
urls_expire_after={'*.fillmurray.com': -1}, # Requests for any subdomain on this site will never expire
allowed_codes=(200, 418), # Cache responses with these status codes
allowed_methods=['GET', 'POST'], # Cache requests with these HTTP methods
include_headers=True, # Cache requests with different headers separately
ignored_params=['auth_token'], # Keep using the cached response even if this param changes
timeout=2.5, # Connection timeout for SQLite backend
)
```
# More Info
To learn more, see:
* [User Guide](https://aiohttp-client-cache.readthedocs.io/en/latest/user_guide.html)
* [Cache Backends](https://aiohttp-client-cache.readthedocs.io/en/latest/backends.html)
* [API Reference](https://aiohttp-client-cache.readthedocs.io/en/latest/reference.html)
* [Examples](https://aiohttp-client-cache.readthedocs.io/en/latest/examples.html)