> For the complete documentation index, see [llms.txt](https://support.cardstack.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://support.cardstack.com/cardstack-products-and-environment/card-environment.md).

# Card Environment

A Cardstack environment is the context that cards run in. By default, it contains:

* an application that cards render in
* an API that receives requests from the frontend, persists changes, and indexes data from external resources
* many data plugins for connecting to different kinds of data sources
* UI interfaces for editing content
* a backing data persistence layer, such as a git repository