---
layout: page_v2
sidebarType: 5
title: Prebid Server | Features | Cache Storage
---

# Prebid Server | Features | Cache Storage

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This feature is currently available only in the Java version of Prebid Server.

This reference is describes how Prebid Server [module](/prebid-server/pbs-modules/) authors can take advantage of storing data needed by their module.

The Prebid Server team recommends one of these solutions:

1. Use internal application data structures like `com.github.benmanes.caffeine.cache.Caffeine`: This provides the fastest approach but is not suitable if you have large amounts of data or need a centralized cache.
2. Using data cache via PBC: Check the [Storage endpoints](/prebid-server/endpoints/pbs-endpoints-pbc.html#cache-storage). This approach provides a centralized caching solution that will be available from each PBS instance configured to connect to the PBC application.

## Using Prebid Cache

To use this approach, you need to inject `PbcStorageService` into your module. You can do this in your module configuration class. For example:

```java
@ConditionalOnProperty(prefix = "hooks." + {ModuleName}Module.CODE, name = "enabled", havingValue = "true")
@Configuration
public class {ModuleName}ModuleConfiguration {

    @Bean
    {ModuleName}Module {moduleName}Module(PbcStorageService cacheService) {
    
        ...
    }
}
```

Then you can use the functions below for storing and retrieving data.

```java
Future<Void> storeEntry(String key,
                                  String value,
                                  ModuleCacheType type,
                                  Integer ttlseconds,
                                  String application,
                                  String appCode);

Future<ModuleCacheResponse> retrieveEntry(String key, String appCode, String application);
```

### storeEntry()

This function writes data through the Prebid Server PBC caching service.

Here is an explanation of the parameters:

{: .table .table-bordered .table-striped }
| Parameter | Scope | Description |
| --- | --- | --- |
| key | required | A name that will be used to reference the stored value. |
| value | required | String representation of the data you need to store. |
| type | required | Represents the format stored inside the value. Can be one of `JSON`, `XML`, `TEXT`. |
| application | required | Configured name of your module storage. This should be configurable in your global or account module config. |
| appCode | required | Use this constant from your module `{ModuleName}Module.CODE` or any other service identifier you are using. |
| ttlseconds | optional | How long (in seconds) the data will be available in the module store. |

### retrieveEntry()

This function reads data from the Prebid Server caching service.

Here is an explanation of the parameters:

{: .table .table-bordered .table-striped }
| Parameter | Scope | Description |
| --- | --- | --- |
| key | required | A name that will be used to reference the stored value. |
| application | required | Configured name of your module storage. This should be configurable in your global or account module config. |
| appCode | required | Use this constant from your module `{ModuleName}Module.CODE` or any other service identifier you are using. |

## Related Reading

- [Prebid Server Modules](/prebid-server/pbs-modules/)