# 4.8. Update REST

If your code extends the REST API, you need to modify namespaces. The `eZ\Publish\Core\REST` and `eZ\Publish\Core\REST\Common\` namespaces have been replaced by `EzSystems\EzPlatformRest`. This is due to the fact that REST code has been moved from Kernel to a new `ezpublish-rest` package.

## Custom installers

eZ Platform provides extension point to create named custom installer which can be used instead of the native one. To use it, execute the Symfony command:

```
php ./bin/console ezplatform:install <installer type name>
```

In eZ Platform v3.0, service definitions around that extension point have changed:

1. The deprecated Clean Installer has been dropped from `ezpublish-kernel` package. If your project uses custom installer and has relied on Clean Installer service definition (`ezplatform.installer.clean_installer`) you need to switch to Core Installer.

**Use:**

```
services:
    Acme\App\Installer\MyCustomInstaller:
        parent: EzSystems\PlatformInstallerBundle\Installer\CoreInstaller
```

**instead of**:

```
services:
    Acme\App\Installer\MyCustomInstaller:
        parent: ezplatform.installer.clean_installer
```

`CoreInstaller` relies on [`DoctrineSchemaBundle`](https://github.com/ezsystems/doctrine-dbal-schema). Custom schema can be installed defining Symfony Event Subscriber subscribing to `EzSystems\DoctrineSchema\API\Event\SchemaBuilderEvents::BUILD_SCHEMA` event.

2. The deprecated Symfony Service definition `ezplatform.installer.db_based_installer` has been removed in favor of its FQCN-named definition.

**Use:**

```
services:
    Acme\App\Installer\MyCustomInstaller:
        parent: EzSystems\PlatformInstallerBundle\Installer\DbBasedInstaller
```

**instead of:**

```
services:
    Acme\App\Installer\MyCustomInstaller:
        parent: ezplatform.installer.db_based_installer
```