---
title: "Extension folder Configuration"
manual: "TYPO3 Explained"
version: "main"
permalink: "https://docs.typo3.org/permalink/t3coreapi:extension-configuration-files@main"
source: "ExtensionArchitecture/FileStructure/Configuration/Index.rst"
modified: "2026-09-15T12:49:12+00:00"
---

# Extension folder `Configuration`

The folder `EXT:my_extension/Configuration/` contains
configuration of different types.

Most subdirectories have reserved names.

Files in the root of this directory and in the `TCA` and
`Backend` subdirectories are automatically included during TYPO3 bootstrap.

The typical file structure is:

-   packages/my_extension/Configuration/
    -   Backend
        -   AjaxRoutes.php
        -   Routes.php
    -   Extbase
        -   Persistence
            -   Classes.php
    -   FlexForms
        -   MyFlexForm1.xml
        -   ...
        -   MyFlexFormN.xml
    -   Fluid
        -   [Namespaces.php](https://docs.typo3.org/permalink/t3coreapi:extension-configuration-fluid-namespaces@main)
        -   [ComponentCollections.php](https://docs.typo3.org/permalink/t3coreapi:extension-configuration-backend-component-collections@main)
    -   RTE
        -   MyRteConfig.yaml
    -   Sets
        -   Set1
            -   config.yaml
            -   page.tsconfig
            -   settings.yaml
            -   settings.defintions.yaml
            -   setup.typoscript
            -   ...
        -   Set2
            -   config.yaml
            -   ...
    -   TCA
        -   Overrides
            -   pages.php
            -   sys_template.php
            -   tt_content.php
            -   ...
            -   tx_otherextension_sometable.php
        -   tx_myextension_domain_model_something.php
        -   ...
        -   tx_myextension_sometable.php
    -   TsConfig
        -   Page
        -   User
    -   TypoScript
        -   Subfolder1
        -   ...
        -   constants.typoscript
        -   setup.typoscript
    -   Yaml
        -   MySpecialConfig.yaml
        -   MyFormSetup.yaml
    -   Icons.php
    -   page.tsconfig
    -   RequestMiddlewares.php
    -   Services.yaml
    -   user.tsconfig

**Sub folders of Configuration**

-   [Backend](https://docs.typo3.org/permalink/t3coreapi:extension-configuration-backend@main)
-   [Extbase](https://docs.typo3.org/permalink/t3coreapi:extbase@main)
    -   [Persistence](https://docs.typo3.org/permalink/t3coreapi:persistence@main)
-   [Fluid](https://docs.typo3.org/permalink/t3coreapi:extension-configuration-fluid@main)
-   [Sets](https://docs.typo3.org/permalink/t3coreapi:extension-configuration-sets@main)
-   [TCA](https://docs.typo3.org/permalink/t3coreapi:extension-configuration-tca@main)
-   [TsConfig](https://docs.typo3.org/permalink/t3coreapi:tsconfig@main)
-   [TypoScript](https://docs.typo3.org/permalink/t3coreapi:typoscript@main)

**Files directly under Configuration**

-   [ContentSecurityPolicies.php](https://docs.typo3.org/permalink/t3coreapi:contentsecuritypolicies-php@main)
-   [Icons.php](https://docs.typo3.org/permalink/t3coreapi:icons-php@main)
-   [page.tsconfig](https://docs.typo3.org/permalink/t3coreapi:page-tsconfig@main)
-   [RequestMiddlewares.php](https://docs.typo3.org/permalink/t3coreapi:requestmiddlewares-php@main)
-   [Services.yaml](https://docs.typo3.org/permalink/t3coreapi:services-yaml@main)
-   [user.tsconfig](https://docs.typo3.org/permalink/t3coreapi:user-tsconfig@main)