> For the complete documentation index, see [llms.txt](https://onestopconcept.gitbook.io/open-endpoints/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://onestopconcept.gitbook.io/open-endpoints/configuration/application-directory-structure/directory-transformers.md).

# Directory: transformers

The **mandatory**`transformers` directory contains one or many transformers defining a [Data Source Transformation](/open-endpoints/configuration/data-source-transformation.md).

The only mandatory attribute is the `data-source`. Omitting all other tags will output the original data-source (xml) without any transformation.

![directory - transformers](https://cdn.openendpoints.io/images/gitbook/directory-transformers.png)