# Redis

## Introduction

The Redis Extension provides application caching and key/value store support via Redis.

Documentation References:

* [Caching](/core-foundation/caching.md)

API References:

* [Cement Redis Extension](https://cement.readthedocs.io/en/3.0/api/ext/ext_redis/)
* [Redis Library](https://redislabs.com/lp/python-redis/)

## Requirements

* Redis

{% hint style="info" %}
Cement 3.0.8+:

`pip install redis`
{% endhint %}

{% hint style="warning" %}
Applications using Cement <3.0.8 should continue to include `redis` in their dependencies.
{% endhint %}

## Configuration

This extension honors the following config settings under a `[cache.redis]` section in any configuration file:

| **Setting**      | **Description**                                                                           |
| ---------------- | ----------------------------------------------------------------------------------------- |
| **expire\_time** | The default time in seconds to expire items in the cache.  Default: `0` (does not expire) |
| **host**         | Redis server ip address or hostname                                                       |
| **port**         | Redis server port                                                                         |
| **db**           | Redis server database id/namespace                                                        |

## Usage

{% tabs %}
{% tab title="Example: Using Redis Cache Handler" %}
{% code title="myapp.py" %}

```python
from cement import App, init_defaults

CONFIG = init_defaults('myapp', 'cache.redis')
CONFIG['cache.redis']['expire_time'] = 300 # seconds
CONFIG['cache.redis']['host'] = '127.0.0.1'
CONFIG['cache.redis']['port'] = 6379
CONFIG['cache.redis']['db'] = 0

class MyApp(App):
    class Meta:
        label = 'myapp'
        config_defaults = CONFIG
        extensions = ['redis']
        cache_handler = 'redis'

with MyApp() as app:
    # Run the app
    app.run()

    # Set a cached value
    app.cache.set('my_key', 'my value')

    # Get a cached value
    app.cache.get('my_key')

    # Delete a cached value
    app.cache.delete('my_key')

    # Delete the entire cache
    app.cache.purge()
```

{% endcode %}

{% code title="\~/.myapp.conf" %}

```
[myapp]

# set the cache handler to use
cache_handler = redis


[cache.redis]

# time in seconds that an item in the cache will expire
expire_time = 300

# Redis server
host = 127.0.0.1

# Redis port
port = 6379

# Redis database number
db = 0
```

{% endcode %}
{% endtab %}
{% endtabs %}


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.builtoncement.com/extensions/redis.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.