---
title: Create an initialization module
slug: cms-11/dev-docs/creating-an-initialization-module
createdAt: 2026-07-22T19:45:22.322Z
---

When you create an initialization module, add a reference to `EPiServer.Framework.dll`. The following initialization code example shows how to set up a property with a default implementation in Initialize, and then the process is undone in `Uninitialize`:

```csharp
[InitializableModule]
public class SampleInitialization: IInitializableModule {
  public void Initialize(InitializationEngine context) {}
  public void Uninitialize(InitializationEngine context) {}
}
```

- **Allow for Initialize to be called multiple times**. If you carry out multi-step initialization in your `Initialize` method, and if it is re-executed because of an error – ensure that the application handles this scenario correctly. Example:

```csharp
private bool _eventAttached;
public void Initialize(InitializationEngine context) {
  if (!_eventAttached) {
    SomeClass.AnEvent += MyEventHandler;
    _eventAttached = true;
  }
  MethodThatMayThrowException();
}
```

- **This **`Initialize`** method may generate an error after the event handler is hooked up.** The initialization system invokes the `Initialize` method again on the next request that reaches the web application, and if the event hook-up is not protected with a flag, it gets added again.
- **The initialization engine makes sure that your code executes in a single-threaded manner**. You do not need to lock regions when you deal with a shared state. This guarantee applies to `Initialize` and `Unintialize` when you execute through the initialization system. If you have custom code that makes calls directly into your initialization module, you may need to deal with multi-threading issues.
- **Remember that the initialization system tracks the initialization state of your module**.
- **Implement**`Uninitialize` . Anything you do with `Initialize` you should undo with `Uninitialize` in the reverse order of `Initialize`.
- If you are using the CMS API, make sure you are adding a module dependency to CMS using `[ModuleDependency(typeof(EPiServer.Web.InitializationModule))]`.