# Obtaining backend source code

In a standard Fleio deployment, Fleio shares backend code between various backend containers (backend, utils, updated, 
celery ...)

If you want to perform enhanced backend customizations, you need the Fleio backend source code.

The Fleio backend source code is available to customers who pay for the Fleio license one year or more in advance.

Frontend source code is available for download as a docker image. Image name format is
`hub.fleio.com/backend_sources-<version>`, where version is encoded as \<year\>-\<month\>:\<number\>. E.g., for the
2023.01.1 Fleio release, the image name is `hub.fleio.com/backend_sources-2023-01:1`.

To download the Fleio backend source code, you need to authenticate to `hub.fleio.com` using your **license ID** and
**license key**.

Authenticate using the following command:

```shell
docker login hub.fleio.com
```


After you are authenticated to `hub.fleio.com`, you can download the Docker image containing backend source code.
For the following command to work, your license must be marked as having access to backend source code.
E.g.:

```shell
docker pull hub.fleio.com/backend_sources-2023-01:1
```

To extract the source from the image, you need to create a docker container. Below is a list of commands to extract
Fleio 2023.01.1 backend source code from an image. After you execute the commands below, a `2023.01.1.tar.gz` archive
containing Fleio backend source should be available in your current host directory.

```shell
container_id=$(docker create hub.fleio.com/backend_sources-2023-01:1 true)
docker cp $container_id:2023.01.1.tar.gz .
docker rm $container_id
```