# Getting started

This page helps you get started with headscale and provides a few usage examples for the headscale command line tool
`headscale`.

!!! note "Prerequisites"

    * Headscale is installed and running as system service. Read the [setup section](../setup/requirements.md) for
      installation instructions.
    * The configuration file exists and is adjusted to suit your environment, see
      [Configuration](../ref/configuration.md) for details.
    * Headscale is reachable from the Internet. Verify this by visiting the health endpoint:
      https://headscale.example.com/health
    * The Tailscale client is installed, see [Client and operating system support](../about/clients.md) for more
      information.

## Getting help

The `headscale` command line tool provides built-in help. To show available commands along with their arguments and
options, run:

=== "Native"

    ```shell
    # Show help
    headscale help

    # Show help for a specific command
    headscale <COMMAND> --help
    ```

=== "Container"

    ```shell
    # Show help
    docker exec -it headscale \
      headscale help

    # Show help for a specific command
    docker exec -it headscale \
      headscale <COMMAND> --help
    ```

!!! note "Manage headscale from another local user"

    By default only the user `headscale` or `root` will have the necessary permissions to access the unix socket
    (`/var/run/headscale/headscale.sock`) that is used to communicate with the service. In order to be able to
    communicate with the headscale service you have to make sure the unix socket is accessible by the user that runs
    the commands. In general you can achieve this by any of the following methods:

      * using `sudo`
      * run the commands as user `headscale`
      * add your user to the `headscale` group
    
    To verify you can run the following command using your preferred method:

    ```shell
    headscale users list
    ```

## Manage headscale users

In headscale, a node (also known as machine or device) is always assigned to a
headscale user. Such a headscale user may have many nodes assigned to them and
can be managed with the `headscale users` command. Invoke the built-in help for
more information: `headscale users --help`.

### Create a headscale user

=== "Native"

    ```shell
    headscale users create <USER>
    ```

=== "Container"

    ```shell
    docker exec -it headscale \
      headscale users create <USER>
    ```

### List existing headscale users

=== "Native"

    ```shell
    headscale users list
    ```

=== "Container"

    ```shell
    docker exec -it headscale \
      headscale users list
    ```

## Register a node

One has to register a node first to use headscale as coordination with Tailscale. The following examples work for the
Tailscale client on Linux/BSD operating systems. Alternatively, follow the instructions to connect
[Android](connect/android.md), [Apple](connect/apple.md) or [Windows](connect/windows.md) devices.

### Normal, interactive login

On a client machine, run the `tailscale up` command and provide the FQDN of your headscale instance as argument:

```shell
tailscale up --login-server <YOUR_HEADSCALE_URL>
```

Usually, a browser window with further instructions is opened and contains the value for `<YOUR_MACHINE_KEY>`. Approve
and register the node on your headscale server:

=== "Native"

    ```shell
    headscale nodes register --user <USER> --key <YOUR_MACHINE_KEY>
    ```

=== "Container"

    ```shell
    docker exec -it headscale \
      headscale nodes register --user <USER> --key <YOUR_MACHINE_KEY>
    ```

### Using a preauthkey

It is also possible to generate a preauthkey and register a node non-interactively. First, generate a preauthkey on the
headscale instance. By default, the key is valid for one hour and can only be used once (see `headscale preauthkeys
--help` for other options):

=== "Native"

    ```shell
    headscale preauthkeys create --user <USER_ID>
    ```

=== "Container"

    ```shell
    docker exec -it headscale \
      headscale preauthkeys create --user <USER_ID>
    ```

The command returns the preauthkey on success which is used to connect a node to the headscale instance via the
`tailscale up` command:

```shell
tailscale up --login-server <YOUR_HEADSCALE_URL> --authkey <YOUR_AUTH_KEY>
```