# Configuration layers

Abstract

Sitecore configuration files are placed into different layers in order to control load order.

Sitecore divides configuration files into layers. Each layer consists of a dedicated folder under the App_config folder. By default, there are four layers:

• Sitecore

• Modules

• Custom

• Environment

Each layer influences a specific area of Sitecore functionality.

Sitecore divides the configuration files into layers in order to:

Sitecore defines the layers and the order in which they load at runtime in the Website/App_Config/layers.config file.

The following table describes the default layers, and where their configurations are stored. All folders are placed under the Website/App_Config folder.

Layer

Config section

Folder

Description

Sitecore

<layer name="Sitecore" includefolder = "/App_config/Sitecore/">

Sitecore

Reserved for Sitecore use.

Contains configuration files for standard Sitecore components and features.

You must not change the order in which configuration files load in this layer, because components are dependent on each other. Changing the default load order can cause components to stop working.

Modules

<layer name="Modules" includefolder = "/App_config/Modules /">

Modules

Reserved for Sitecore use.

Contains configuration files for official Sitecore modules, such as Web Forms for Marketers.

When you install a module, its configuration files are added to its associated folder under the Modules folder. In addition, the layers.config file is updated with the module's load order and the path to the module's configuration folder. By default, modules load in the order they were installed.

Custom

<layer name="Custom" includefolder = "/App_config/Include /">

Include

Contains the patch files you create in order to modify settings in the default Sitecore configuration.

Environment

<layer name="Environment" includefolder = "/App_config/Environment /">

Environment

Contains the patch files you create to configure Sitecore for different environments, such as QA, production, or development.

For example, in a development environment, you can add patch files that enable additional logging information.

To change Sitecore settings, you can place patch files in the Custom and Environment layers.

### Important

You must not modify or add files in the Sitecore or Modules layers. Changes to files in these layers can affect the stability of the platform and can be lost during an upgrade

By default, Sitecore loads its configuration files in this order:

1. Basic system files, such as layers.config, ConnectionStrings.config, and web.config.

2. Configuration files in the Sitecore layer.

3. Configuration files in the Modules layer.

4. Configuration files in the Custom layer.

5. Configuration files in the Environment layer.

### Important

Do not change the order in which the layers load.

Within each layer, by default, Sitecore goes through all the subfolders in the layer recursively and loads the files in each subfolder in alphabetical order. Files in the root of a folder are merged before files in subfolders within the folder. For example, the file /App_Config/Include/mywebsite9.config loads before the file /App_Config/Include/Myfolder/mywebsite1.config.

If you want more control over the sequence in which your patch files load, you can add a <loadOrder> setting to the layer.