> For the complete documentation index, see [llms.txt](https://quantumphp.gitbook.io/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://quantumphp.gitbook.io/docs/packages/cache/overview.md).

# Overview

Cache gives you a PSR-16 style API for short-lived application data without tying your code to one backend.

Use it for things like computed fragments, lookup results, throttling support data, or other values you can safely rebuild.

## Entry point

Use the `cache()` helper.

```php
cache()->set('settings.homepage', $payload, 300);

$payload = cache()->get('settings.homepage');
```

`cache()` returns a `Quantum\Cache\Cache` wrapper. When you do not pass an adapter name, the factory uses `cache.default` from `config/cache.php`.

## Supported adapters

Quantum ships four built-in adapters:

* `file`
* `database`
* `memcached`
* `redis`

The factory keeps one resolved `Cache` instance per adapter name for the life of the current DI-managed factory instance. Repeated calls like `cache('redis')` reuse the same wrapper and underlying adapter.

## What the package guarantees

* cache config is loaded lazily on first use
* all built-in adapters serialize values before storage
* `null` TTL uses the adapter's configured default TTL
* unsupported adapter names fail during resolution
* unsupported forwarded method calls fail on the wrapper

## Important caveats

* `clear()` is backend-wide for the configured store. It is not limited to the current prefix or to keys created by one caller.
* batch methods accept arrays only, even though the PSR signatures say `iterable`
* expiry cleanup is lazy for file and database storage: expired entries are removed when they are checked


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## 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, and the optional `goal` query parameter:

```
GET https://quantumphp.gitbook.io/docs/packages/cache/overview.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

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.