}).overrideAttrs
      (attrs: {
        # I don't want emacs.desktop file because I only use
        # emacsclient.
        postInstall = (attrs.postInstall or "") + ''
          rm $out/share/applications/emacs.desktop
        '';
      });
in
[
  # ...
]
```
:::

After building this file as shown in [](#ex-emacsNix), you
will get an GTK 3-based Emacs binary pre-loaded with your favorite packages.

## Running Emacs as a Service {#module-services-emacs-running}

NixOS provides an optional
{command}`systemd` service which launches
[Emacs daemon](https://www.gnu.org/software/emacs/manual/html_node/emacs/Emacs-Server.html)
with the user's login session.

*Source:* {file}`modules/services/editors/emacs.nix`

### Enabling the Service {#module-services-emacs-enabling}

To install and enable the {command}`systemd` user service for Emacs
daemon, add the following to your {file}`configuration.nix`:
```nix
{ services.emacs.enable = true; }
```

The {var}`services.emacs.package` option allows a custom
derivation to be used, for example, one created by
`emacsWithPackages`.

Ensure that the Emacs server is enabled for your user's Emacs
configuration, either by customizing the {var}`server-mode`
variable, or by adding `(server-start)` to
{file}`~/.emacs.d/init.el`.

To start the daemon, execute the following:
```ShellSession
$ nixos-rebuild switch  # to activate the new configuration.nix
$ systemctl --user daemon-reload        # to force systemd reload
$ systemctl --user start emacs.service  # to start the Emacs daemon
```
The server should now be ready to serve Emacs clients.

### Starting the client {#module-services-emacs-starting-client}

Ensure that the Emacs server is enabled, either by customizing the
{var}`server-mode` variable, or by adding
`(server-start)` to {file}`~/.emacs`.

To connect to the Emacs daemon, run one of the following:
```
emacsclient FILENAME
emacsclient --create-frame  # opens a new frame (window)
emacsclient --create-frame --tty  # opens a new frame on the current terminal
```

### Configuring the {var}`EDITOR` variable {#module-services-emacs-editor-variable}

<!--<title>{command}`emacsclient` as the Default Editor</title>-->