---
title: "Extension folder Configuration"
manual: "TYPO3 Explained"
version: "12.4"
permalink: "https://docs.typo3.org/permalink/t3coreapi:extension-configuration-files@12.4"
source: "ExtensionArchitecture/FileStructure/Configuration/Index.rst"
rendered: "2026-10-21T15:29:37+00:00"
---

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<a id="extension-files-configuration"></a>

# Extension folder `Configuration` {#extension-configuration-files}

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

Some of the sub directories in here have reserved names with special meanings.

All files in this directory and in the sub directories `TCA` and
`Backend` are automatically included during the TYPO3 bootstrap.

The following files and folders are commonly found in the `Configuration`
folder:

**Common content of the configuration folder**

```none
$ tree packages/my_extension/Configuration/
├── Backend
│    ├── AjaxRoutes.php
│    └── Routes.php
├── Extbase
│    └── Persistence
│         └── Classes.php
├── FlexForms
│    ├── MyFlexForm1.xml
│    ├── ...
│    └── MyFlexFormN.xml
├── RTE
│    └── MyRteConfig.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
```

**Sub folders of Configuration**

-   [Backend](https://docs.typo3.org/permalink/t3coreapi:extension-folder-configuration-backend@12.4)
-   [Extbase](https://docs.typo3.org/permalink/t3coreapi:extbase@12.4)
    -   [Persistence](https://docs.typo3.org/permalink/t3coreapi:file-persistence@12.4)
-   [TCA](https://docs.typo3.org/permalink/t3coreapi:extension-folder-configuration-tca@12.4)
-   [TsConfig](https://docs.typo3.org/permalink/t3coreapi:file-tsconfig@12.4)
-   [TypoScript](https://docs.typo3.org/permalink/t3coreapi:file-typoscript@12.4)

**Files directly under Configuration**

-   [ContentSecurityPolicies.php](https://docs.typo3.org/permalink/t3coreapi:file-contentsecuritypolicies-php@12.4)
-   [Icons.php](https://docs.typo3.org/permalink/t3coreapi:file-icons-php@12.4)
-   [page.tsconfig](https://docs.typo3.org/permalink/t3coreapi:file-page-tsconfig@12.4)
-   [RequestMiddlewares.php](https://docs.typo3.org/permalink/t3coreapi:file-requestmiddlewares-php@12.4)
-   [Services.yaml](https://docs.typo3.org/permalink/t3coreapi:services-yaml@12.4)