`extract` expects an argument with the `src` attribute, and either a `name` attribute or `pname` and `version` attributes.

::: {.note}
In the past, `appimageTools` provided both `extractType1` and `extractType2`, to be used depending on the type of AppImage that was being extracted.
However, [those were unified early 2020](https://github.com/NixOS/nixpkgs/pull/81572), meaning that both `extractType1` and `extractType2` have the same behaviour as `extract` now.
:::

:::{.example #ex-extracting-appimage}

# Extracting an AppImage to install extra files

This example was adapted from a real package in Nixpkgs to show how `extract` is usually used in combination with `wrapType2`.
Note how `appimageContents` is used in `extraInstallCommands` to install additional files that were extracted from the AppImage.

```nix
{ appimageTools, fetchurl }:
let
  pname = "irccloud";
  version = "0.16.0";

  src = fetchurl {
    url = "https://github.com/irccloud/irccloud-desktop/releases/download/v${version}/IRCCloud-${version}-linux-x86_64.AppImage";
    hash = "sha256-/hMPvYdnVB1XjKgU2v47HnVvW4+uC3rhRjbucqin4iI=";
  };

  appimageContents = appimageTools.extract { inherit pname version src; };
in
appimageTools.wrapType2 {
  inherit pname version src;

  extraPkgs = pkgs: [ pkgs.at-spi2-core ];

  extraInstallCommands = ''
    mv $out/bin/${pname}-${version} $out/bin/${pname}
    install -m 444 -D ${appimageContents}/irccloud.desktop $out/share/applications/irccloud.desktop
    install -m 444 -D ${appimageContents}/usr/share/icons/hicolor/512x512/apps/irccloud.png \
      $out/share/icons/hicolor/512x512/apps/irccloud.png
    substituteInPlace $out/share/applications/irccloud.desktop \
      --replace-fail 'Exec=AppRun' 'Exec=${pname}'
  '';
}
```

:::

The argument passed to `extract` can also contain a `postExtract` attribute, which allows you to execute additional commands after the files are extracted from the AppImage.
`postExtract` must be a string with commands to run.

:::{.example #ex-extracting-appimage-with-postextract}

# Extracting an AppImage to install extra files, using `postExtract`

This is a rewrite of [](#ex-extracting-appimage) to use `postExtract`.

```nix
{ appimageTools, fetchurl }:
let
  pname = "irccloud";
  version = "0.16.0";

  src = fetchurl {
    url = "https://github.com/irccloud/irccloud-desktop/releases/download/v${version}/IRCCloud-${version}-linux-x86_64.AppImage";
    hash = "sha256-/hMPvYdnVB1XjKgU2v47HnVvW4+uC3rhRjbucqin4iI=";
  };

  appimageContents = appimageTools.extract {
    inherit pname version src;
    postExtract = ''
      substituteInPlace $out/irccloud.desktop --replace-fail 'Exec=AppRun' 'Exec=${pname}'
    '';
  };
in
appimageTools.wrapType2 {
  inherit pname version src;

  extraPkgs = pkgs: [ pkgs.at-spi2-core ];

  extraInstallCommands = ''
    mv $out/bin/${pname}-${version} $out/bin/${pname}
    install -m 444 -D ${appimageContents}/irccloud.desktop $out/share/applications/irccloud.desktop
    install -m 444 -D ${appimageContents}/usr/share/icons/hicolor/512x512/apps/irccloud.png \
      $out/share/icons/hicolor/512x512/apps/irccloud.png
  '';
}
```

:::