path: root/doc/flatpak-metadata.xml

<?xml version='1.0'?> <!--*-nxml-*-->
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
    "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd">

<refentry id="flatpak-metadata">

    <refentryinfo>
        <title>flatpak metadata</title>
        <productname>flatpak</productname>

        <authorgroup>
            <author>
                <contrib>Developer</contrib>
                <firstname>Alexander</firstname>
                <surname>Larsson</surname>
                <email>alexl@redhat.com</email>
            </author>
        </authorgroup>
    </refentryinfo>

    <refmeta>
        <refentrytitle>flatpak metadata</refentrytitle>
        <manvolnum>5</manvolnum>
    </refmeta>

    <refnamediv>
        <refname>flatpak-metadata</refname>
        <refpurpose>Information about an application or runtime</refpurpose>
    </refnamediv>

    <refsect1>
        <title>Description</title>

        <para>
            Flatpak uses metadata files to describe applications and runtimes.
            The <filename>metadata</filename> file for a deployed application or
            runtime is placed in the toplevel deploy directory. For example, the
            metadata for the locally installed application org.gnome.Calculator
            is in
            <filename>~/.local/share/flatpak/app/org.gnome.Calculator/current/active/metadata</filename>.
        </para>

        <para>
            Most aspects of the metadata configuration can be overridden when
            launching applications, either temporarily via options of the flatpak
            run command, or permanently with the flatpak override command.
        </para>

        <para>
            A metadata file describing the effective configuration is available
            inside the running sandbox at <filename>/.flatpak-info</filename>.
            For compatibility with older Flatpak versions,
            <filename>/run/user/$UID/flatpak-info</filename> is a symbolic
            link to the same file.
        </para>
    </refsect1>

    <refsect1>
        <title>File format</title>

        <para>
            The metadata file is using the same .ini file format that is used for
            systemd unit files or application .desktop files.
        </para>

        <refsect2>
            <title>[Application] or [Runtime]</title>

            <para>
                Metadata for applications starts with an [Application] group,
                metadata for runtimes with a [Runtime] group.
            </para>
            <para>
                The following keys can be present in these groups:
            </para>
            <variablelist>
                <varlistentry>
                    <term><option>name</option> (string)</term>
                    <listitem><para>The name of the application or runtime. This key is mandatory.</para></listitem>
                </varlistentry>
                <varlistentry>
                    <term><option>runtime</option> (string)</term>
                    <listitem><para>The fully qualified name of the runtime that is used by the application. This key is mandatory for applications.</para></listitem>
                </varlistentry>
                <varlistentry>
                    <term><option>sdk</option> (string)</term>
                    <listitem>
                      <para>
                        The fully qualified name of the sdk that matches the
                        runtime. Available since 0.1.</para>
                    </listitem>
                </varlistentry>
                <varlistentry>
                    <term><option>command</option> (string)</term>
                    <listitem>
                      <para>
                        The command to run. Only relevant for applications.
                        Available since 0.1.
                      </para>
                    </listitem>
                </varlistentry>
                <varlistentry>
                    <term><option>required-flatpak</option> (string list)</term>
                    <listitem><para>
                        The required version of Flatpak to run this application
                        or runtime. For applications, this was available since
                        0.8.0. For runtimes, this was available since 0.9.1,
                        and backported to 0.8.3 for the 0.8.x branch.
                      </para><para>
                        Flatpak after version 1.4.3 and 1.2.5 support multiple versions here.
                        This can be useful if you need to support features that are backported
                        to a previous stable series. For example if you want to use a feature
                        added in 1.6.0 that was also backported to 1.4.4 you would use
                        <literal>1.6.0;1.4.4;</literal>. Note that older versions of flatpak will
                        just use the first element in the list, so make that the largest version.
                    </para></listitem>
                </varlistentry>
                <varlistentry>
                    <term><option>tags</option> (string list)</term>
                    <listitem><para>
                        Tags to include in AppStream XML. Typical values
                        in use on Flathub include
                        <option>beta</option>, <option>stable</option>,
                        <option>proprietary</option>
                        and <option>upstream-maintained</option>.
                        Available since 0.4.12.
                    </para></listitem>
                </varlistentry>
            </variablelist>
        </refsect2>
        <refsect2>
            <title>[Context]</title>
            <para>
                This group determines various system resources that may be shared
                with the application when it is run in a flatpak sandbox.
            </para>
            <para>
                All keys in this group (and the group itself) are optional.
            </para>
            <variablelist>
                <varlistentry>
                    <term><option>shared</option> (list)</term>
                    <listitem><para>
                        List of subsystems to share with the host system.
                        Possible subsystems: network, ipc.
                        Available since 0.3.
                    </para></listitem>
                </varlistentry>

                <varlistentry>
                    <term><option>sockets</option> (list)</term>
                    <listitem><para>
                        List of well-known sockets to make available in the sandbox.
                        Possible sockets: x11, wayland, fallback-x11, pulseaudio, session-bus, system-bus,
                        ssh-auth, pcsc, cups.
                        When making a socket available, flatpak also sets
                        well-known environment variables like DISPLAY or
                        DBUS_SYSTEM_BUS_ADDRESS to let the application
                        find sockets that are not in a fixed location.
                        Available since 0.3.
                    </para></listitem>
                </varlistentry>

                <varlistentry>
                    <term><option>devices</option> (list)</term>
                    <listitem><para>
                        List of devices to make available in the sandbox.
                        Possible values:
                        <variablelist>

                            <varlistentry><term><option>dri</option></term>
                            <listitem><para>
                                Graphics direct rendering
                                (<filename>/dev/dri</filename>).
                                Available since 0.3.
                            </para></listitem></varlistentry>

                            <varlistentry><term><option>kvm</option></term>
                            <listitem><para>
                                Virtualization
                                (<filename>/dev/kvm</filename>).
                                Available since 0.6.12.
                            </para></listitem></varlistentry>

                            <varlistentry><term><option>all</option></term>
                            <listitem><para>
                                All device nodes in <filename>/dev</filename>, but not /dev/shm (which is separately specified).
                                Available since 0.6.6.
                            </para></listitem></varlistentry>

                            <varlistentry><term><option>shm</option></term>
                            <listitem><para>
                                Access to the host /dev/shm
                                (<filename>/dev/shm</filename>).
                                Available since 1.6.1.
                            </para></listitem></varlistentry>

                        </variablelist>
                    </para></listitem>
                </varlistentry>

                <varlistentry>
                    <term><option>filesystems</option> (list)</term>
                    <listitem><para>
                        List of filesystem subsets to make available to the
                        application. Possible values:
                        <variablelist>

                            <varlistentry><term><option>home</option></term>
                            <listitem><para>
                                The entire home directory.
                                Available since 0.3.
                            </para></listitem></varlistentry>

                            <varlistentry><term><option>home/<replaceable>path</replaceable></option></term><listitem><para>
                                  Alias for <filename>~/path</filename>
                                  Available since 1.10.
                                  For better compatibility with older
                                  Flatpak versions, prefer to write this
                                  as <filename>~/path</filename>.
                            </para></listitem></varlistentry>

                            <varlistentry><term><option>host</option></term>
                            <listitem><para>
                                The entire host file system, except for
                                directories that are handled specially by
                                Flatpak.
                                In particular, this shares
                                <filename>/home</filename>,
                                <filename>/media</filename>,
                                <filename>/opt</filename>,
                                <filename>/run/media</filename> and
                                <filename>/srv</filename> if they exist.
                            </para>
                            <para>
                                <filename>/dev</filename> is not shared:
                                use <option>devices=all;</option> instead.
                            </para>
                            <para>
                                Parts of <filename>/sys</filename> are always
                                shared. This option does not make additional
                                files in /sys available.
                            </para>
                            <para>
                                Additionally, this keyword provides all of the
                                same directories in
                                <filename>/run/host</filename> as the
                                <option>host-os</option> and
                                <option>host-etc</option> keywords.
                                If this keyword is used in conjunction
                                with one of the <option>host-</option>
                                keywords, whichever access level is higher
                                (more permissive) will be used for the
                                directories in <filename>/run/host</filename>:
                                for example,
                                <code>host:rw;host-os:ro;</code> is
                                equivalent to <code>host:rw;</code>.
                            </para>
                            <para>
                                These other reserved directories are
                                currently excluded:
                                <filename>/app</filename>,
                                <filename>/bin</filename>,
                                <filename>/boot</filename>,
                                <filename>/efi</filename>,
                                <filename>/etc</filename>,
                                <filename>/lib</filename>,
                                <filename>/lib32</filename>,
                                <filename>/lib64</filename>,
                                <filename>/proc</filename>,
                                <filename>/root</filename>,
                                <filename>/run</filename>,
                                <filename>/sbin</filename>,
                                <filename>/tmp</filename>,
                                <filename>/usr</filename>,
                                <filename>/var</filename>.
                            </para>
                            <para>
                                Available since 0.3.
                            </para></listitem></varlistentry>

                            <varlistentry><term><option>host-os</option></term>
                            <listitem><para>
                                The host operating system's libraries,
                                executables and static data from
                                <filename>/usr</filename>
                                and the related directories
                                <filename>/bin</filename>,
                                <filename>/lib</filename>,
                                <filename>/lib32</filename>,
                                <filename>/lib64</filename>,
                                <filename>/sbin</filename>.
                                Additionally, this keyword provides access
                                to a subset of <filename>/etc</filename> that
                                is associated with packaged libraries and
                                executables, even if the
                                <option>host-etc</option> keyword
                                was not used:
                                <filename>/etc/ld.so.cache</filename>,
                                (used by the dynamic linker) and
                                <filename>/etc/alternatives</filename>
                                (on operating systems that use it, such as
                                Debian).
                            </para>
                            <para>
                                To avoid conflicting with the Flatpak
                                runtime, these are mounted in the sandbox
                                at <filename>/run/host/usr</filename>,
                                <filename>/run/host/etc/ld.so.cache</filename>
                                and so on.
                            </para>
                            <para>
                                Available since 1.7.
                            </para></listitem></varlistentry>

                            <varlistentry><term><option>host-etc</option></term>
                            <listitem><para>
                                The host operating system's configuration from
                                <filename>/etc</filename>.
                            </para>
                            <para>
                                To avoid conflicting with the Flatpak
                                runtime, this is mounted in the sandbox
                                at <filename>/run/host/etc</filename>.
                            </para>
                            <para>
                                Available since 1.7.
                            </para></listitem></varlistentry>

                            <varlistentry><term><option>xdg-desktop</option>,
                                <option>xdg-documents</option>,
                                <option>xdg-download</option>,
                                <option>xdg-music</option>,
                                <option>xdg-pictures</option>,
                                <option>xdg-public-share</option>,
                                <option>xdg-videos</option>,
                                <option>xdg-templates</option>
                            </term><listitem><para>
                                <ulink url="https://www.freedesktop.org/wiki/Software/xdg-user-dirs/"
                                  >freedesktop.org special directories</ulink>.
                                Available since 0.3.
                            </para></listitem></varlistentry>

                            <varlistentry><term><option>xdg-desktop/<replaceable>path</replaceable></option>,
                                <option>xdg-documents/<replaceable>path</replaceable></option>,
                                etc.
                            </term><listitem><para>
                                Subdirectories of freedesktop.org special
                                directories. Available since 0.4.13.
                            </para></listitem></varlistentry>

                            <varlistentry><term>
                                <option>xdg-cache</option>,
                                <option>xdg-config</option>,
                                <option>xdg-data</option>
                            </term><listitem><para>
                                Directories defined by the
                                <ulink url="https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html"
                                  >freedesktop.org Base Directory Specification</ulink>.
                                Available since 0.6.14.
                            </para></listitem></varlistentry>

                            <varlistentry><term>
                                <option>xdg-cache/<replaceable>path</replaceable></option>,
                                <option>xdg-config/<replaceable>path</replaceable></option>,
                                <option>xdg-data/<replaceable>path</replaceable></option>
                            </term><listitem><para>
                                Subdirectories of directories defined by the
                                freedesktop.org Base Directory Specification.
                                Available since 0.6.14.
                            </para></listitem></varlistentry>

                            <varlistentry><term>
                                <option>xdg-run/<replaceable>path</replaceable></option>
                            </term><listitem><para>
                                Subdirectories of the
                                <envar>XDG_RUNTIME_DIR</envar> defined by the
                                freedesktop.org Base Directory Specification.
                                Note that <option>xdg-run</option> on its own
                                is not supported. Available since 0.4.13.
                            </para></listitem></varlistentry>

                            <varlistentry><term>
                                <option>/<replaceable>path</replaceable></option>
                            </term><listitem><para>
                                An arbitrary absolute path. Available since 0.3.
                            </para></listitem></varlistentry>

                            <varlistentry><term>
                                <option>~/<replaceable>path</replaceable></option>
                            </term><listitem><para>
                                An arbitrary path relative to the home
                                directory. Available since 0.3.
                            </para></listitem></varlistentry>

                            <varlistentry><term><option>~</option></term>
                            <listitem><para>
                                  The same as <option>home</option>.
                                  Available since 1.10.
                                  For better compatibility with older
                                  Flatpak versions, prefer to write this
                                  as <option>home</option>.
                            </para></listitem></varlistentry>

                            <varlistentry><term>
                                One of the above followed by
                                <option>:ro</option>
                            </term><listitem><para>
                                Make the given directory available read-only.
                            </para></listitem></varlistentry>

                            <varlistentry><term>
                                One of the above followed by
                                <option>:rw</option>
                            </term><listitem><para>
                                Make the given directory available read/write.
                                This is the default.
                            </para></listitem></varlistentry>

                            <varlistentry><term>
                                One of the above followed by
                                <option>:create</option>
                            </term><listitem><para>
                                Make the given directory available read/write,
                                and create it if it does not already exist.
                            </para></listitem></varlistentry>

                        </variablelist>
                    </para></listitem>
                </varlistentry>
                <varlistentry>
                    <term><option>persistent</option> (list)</term>
                    <listitem><para>
                      List of homedir-relative paths to make available at
                      the corresponding path in the per-application home directory,
                      allowing the locations to be used for persistent data when
                      the application does not have access to the real homedir.
                      For instance making ".myapp" persistent would make "~/.myapp"
                      in the sandbox a bind mount to "~/.var/app/org.my.App/.myapp",
                      thus allowing an unmodified application to save data in
                      the per-application location. Available since 0.3.
                    </para></listitem>
                </varlistentry>
                <varlistentry>
                    <term><option>features</option> (list)</term>
                    <listitem><para>
                        List of features available or unavailable to the
                        application, currently from the following list:
                        <variablelist>

                            <varlistentry><term><option>devel</option></term>
                            <listitem><para>
                                Allow system calls used by development-oriented
                                tools such as <command>perf</command>,
                                <command>strace</command> and
                                <command>gdb</command>.
                                Available since 0.6.10.
                            </para></listitem></varlistentry>

                            <varlistentry><term><option>multiarch</option></term>
                            <listitem><para>
                                Allow running multilib/multiarch binaries, for
                                example <literal>i386</literal> binaries in an
                                <literal>x86_64</literal> environment.
                                Available since 0.6.12.
                            </para></listitem></varlistentry>

                            <varlistentry><term><option>bluetooth</option></term>
                            <listitem><para>
                              Allow the application to use bluetooth (AF_BLUETOOTH) sockets.
                              Note, for bluetooth to fully work you must also have network access.
                              Available since 0.11.8.
                            </para></listitem></varlistentry>

                            <varlistentry><term><option>canbus</option></term>
                            <listitem><para>
                              Allow the application to use canbus (AF_CAN) sockets.
                              Note, for this work you must also have network access.
                              Available since 1.0.3.
                            </para></listitem></varlistentry>

                            <varlistentry><term><option>per-app-dev-shm</option></term>
                            <listitem><para>
                              Share a single instance of
                              <filename>/dev/shm</filename> between all
                              instances of this application run by the same
                              user ID, including sub-sandboxes.
                              If the application has the
                              <option>shm</option> device permission in its
                              <option>devices</option> list, then this
                              feature flag is ignored.
                              Available since 1.12.0.
                            </para></listitem></varlistentry>

                        </variablelist>
                        A feature can be prefixed with <option>!</option> to
                        indicate the absence of that feature, for example
                        <option>!devel</option> if development and debugging
                        are not allowed.
                    </para></listitem>
                </varlistentry>
                <varlistentry>
                    <term><option>unset-environment</option> (list)</term>
                    <listitem><para>
                        A list of names of environment variables to unset.
                        Note that environment variables to set to a value
                        (possibly empty) appear in the [Environment]
                        group instead.
                    </para></listitem>
                </varlistentry>
            </variablelist>
        </refsect2>
        <refsect2>
            <title>[Instance]</title>
            <para>
                This group only appears in <filename>/.flatpak-info</filename>
                for a running app, and not in the metadata files written by
                application authors. It is filled in by Flatpak itself.
            </para>
            <!-- In versions prior to 0.6.10 some of this information was
            in [Application], but for simplicity that isn't documented
            here. -->
            <variablelist>
                <varlistentry>
                    <term><option>instance-id</option> (string)</term>
                    <listitem><para>
                        The ID of the running instance. This number is
                        used as the name of the directory in
                        <filename><envar>XDG_RUNTIME_DIR</envar>/.flatpak</filename>
                        where Flatpak stores information about this instance.
                    </para></listitem>
                </varlistentry>
                <varlistentry>
                    <term><option>instance-path</option> (string)</term>
                    <listitem><para>
                        The absolute path on the host system of the app's
                        persistent storage area in <filename>$HOME/.var</filename>.
                    </para></listitem>
                </varlistentry>
                <varlistentry>
                    <term><option>app-path</option> (string)</term>
                    <listitem><para>
                        The absolute path on the host system of the app's
                        app files, as mounted at <filename>/app</filename>
                        inside the container. Available since 0.6.10.
                    </para></listitem>
                    <listitem><para>
                        Since 1.12.0, if <command>flatpak run</command>
                        was run with the <option>--app-path</option> option,
                        this key gives the absolute path of whatever files
                        were mounted on <filename>/app</filename>, even if
                        that differs from the app's normal app files.
                    </para></listitem>
                    <listitem><para>
                        If <command>flatpak run</command> was run with
                        <option>--app-path=</option> (resulting in an
                        empty directory being mounted on
                        <filename>/app</filename>), the value is set to
                        the empty string.
                    </para></listitem>
                </varlistentry>
                <varlistentry>
                    <term><option>original-app-path</option> (string)</term>
                    <listitem><para>
                        If <command>flatpak run</command> was run with the
                        <option>--app-path</option> option, this key gives
                        the absolute path of the app's original files,
                        as mounted at <filename>/run/parent/app</filename>
                        inside the container. Available since 1.12.0.
                    </para></listitem>
                    <listitem><para>
                        If this key is missing, the app files are given
                        by <option>app-path</option>.
                    </para></listitem>
                </varlistentry>
                <varlistentry>
                    <term><option>app-commit</option> (string)</term>
                    <listitem><para>
                        The commit ID of the application that is running.
                        The filename of a deployment of this commit can
                        be found in <option>original-app-path</option>
                        if present, or <option>app-path</option> otherwise.
                    </para></listitem>
                </varlistentry>
                <varlistentry>
                    <term><option>app-extensions</option> (list of strings)</term>
                    <listitem><para>
                        A list of app extensions that are mounted into
                        the running instance. The format for each list item is
                        <option>EXTENSION_ID=COMMIT</option>.
                        If <option>original-app-path</option> is present,
                        the extensions are mounted below
                        <filename>/run/parent/app</filename>; otherwise,
                        they are mounted below <filename>/app</filename>.
                    </para></listitem>
                </varlistentry>
                <varlistentry>
                    <term><option>branch</option> (string)</term>
                    <listitem><para>
                        The branch of the app, for example
                        <literal>stable</literal>. Available since
                        0.6.10.
                    </para></listitem>
                </varlistentry>
                <varlistentry>
                    <term><option>arch</option> (string)</term>
                    <listitem><para>
                        The architecture of the running instance.
                    </para></listitem>
                </varlistentry>
                <varlistentry>
                    <term><option>flatpak-version</option> (string)</term>
                    <listitem><para>
                        The version number of the Flatpak version that ran
                        this app. Available since 0.6.11.
                    </para></listitem>
                </varlistentry>
                <varlistentry>
                    <term><option>runtime-path</option> (string)</term>
                    <listitem><para>
                        The absolute path on the host system of the app's
                        runtime files, as mounted at <filename>/usr</filename>
                        inside the container. Available since 0.6.10.
                    </para></listitem>
                    <listitem><para>
                        Since 1.12.0, if <command>flatpak run</command>
                        was run with the <option>--usr-path</option> option,
                        this key gives the absolute path of whatever files
                        were mounted on <filename>/usr</filename>, even if
                        that differs from the app's normal runtime files.
                    </para></listitem>
                </varlistentry>
                <varlistentry>
                    <term><option>original-runtime-path</option> (string)</term>
                    <listitem><para>
                        If <command>flatpak run</command> was run with the
                        <option>--runtime-path</option> option, this key gives
                        the absolute path of the app's original runtime,
                        as mounted at <filename>/run/parent/usr</filename>
                        inside the container. Available since 1.12.0.
                    </para></listitem>
                    <listitem><para>
                        If this key is missing, the runtime files are given
                        by <option>runtime-path</option>.
                    </para></listitem>
                </varlistentry>
                <varlistentry>
                    <term><option>runtime-commit</option> (string)</term>
                    <listitem><para>
                        The commit ID of the runtime that is used.
                        The filename of a deployment of this commit can be
                        found in <option>original-runtime-path</option>
                        if present, or <option>runtime-path</option>
                        otherwise.
                    </para></listitem>
                </varlistentry>
                <varlistentry>
                    <term><option>runtime-extensions</option> (list of strings)</term>
                    <listitem><para>
                        A list of runtime extensions that are mounted into
                        the running instance. The format for each list item is
                        <option>EXTENSION_ID=COMMIT</option>.
                        If <option>original-app-path</option> is present,
                        the extensions are mounted below
                        <filename>/run/parent/usr</filename>; otherwise,
                        they are mounted below <filename>/usr</filename>.
                    </para></listitem>
                </varlistentry>
                <varlistentry>
                    <term><option>extra-args</option> (string)</term>
                    <listitem><para>
                        Extra arguments that were passed to flatpak run.
                    </para></listitem>
                </varlistentry>
                <varlistentry>
                    <term><option>sandbox</option> (boolean)</term>
                    <listitem><para>
                        Whether the <option>--sandbox</option> option was passed
                        to flatpak run.
                    </para></listitem>
                </varlistentry>
                <varlistentry>
                    <term><option>build</option> (boolean)</term>
                    <listitem><para>
                        Whether this instance was created by flatpak build.
                    </para></listitem>
                </varlistentry>
                <varlistentry>
                    <term><option>session-bus-proxy</option> (boolean)</term>
                    <listitem><para>
                        True if this app cannot access the D-Bus session bus
                        directly (either it goes via a proxy, or it cannot
                        access the session bus at all). Available since 0.8.0.
                        <!-- TODO: Those semantics are weird, are they
                        intended? -->
                    </para></listitem>
                </varlistentry>
                <varlistentry>
                    <term><option>system-bus-proxy</option> (boolean)</term>
                    <listitem><para>
                        True if this app cannot access the D-Bus system bus
                        directly (either it goes via a proxy, or it cannot
                        access the system bus at all). Available since 0.8.0.
                        <!-- TODO: Those semantics are weird, are they
                        intended? -->
                    </para></listitem>
                </varlistentry>
            </variablelist>
        </refsect2>
        <refsect2>
            <title>[Session Bus Policy]</title>
            <para>
                If the <option>sockets</option> key is not allowing full access
                to the D-Bus session bus, then flatpak provides filtered access.
            </para>
            <para>
                The default policy for the session bus only allows the
                application to own its own application ID and
                subnames. For instance if the app is called
                "org.my.App", it can only own "org.my.App" and
                "org.my.App.*". Its also only allowed to talk to the
                bus itself (org.freedesktop.DBus) and the portal APIs
                APIs (bus names of the form org.freedesktop.portal.*).
            </para>
            <para>
                Additionally the app is always allowed to reply to
                messages sent to it, and emit broadcast signals (but
                these will not reach other sandboxed apps unless they
                are allowed to talk to your app.
            </para>
            <para>
                If the [Session Bus Policy] group is present, it provides
                policy for session bus access.
            </para>
            <para>
                Each key in this group has the form of a D-Bus bus name or
                prefix thereof, for example <option>org.gnome.SessionManager</option>
                or <option>org.freedesktop.portal.*</option>
            </para>
            <para>
                The possible values for entry are, in increasing order or
                access:
            </para>
            <variablelist>
                <varlistentry>
                    <term><option>none</option></term>
                    <listitem><para>
                        The bus name or names in question is invisible to the application.
                        Available since 0.2.
                    </para></listitem>
                </varlistentry>
                <varlistentry>
                    <term><option>see</option></term>
                    <listitem><para>
                        The bus name or names can be enumerated by the application.
                        Available since 0.2.
                    </para></listitem>
                </varlistentry>
                <varlistentry>
                    <term><option>talk</option></term>
                    <listitem><para>
                        The application can send messages/ and receive replies and signals from the bus name or names.
                        Available since 0.2.
                    </para></listitem>
                </varlistentry>
                <varlistentry>
                    <term><option>own</option></term>
                    <listitem><para>
                        The application can own the bus name or names (as well as all the above).
                        Available since 0.2.
                    </para></listitem>
                </varlistentry>
            </variablelist>
        </refsect2>
        <refsect2>
            <title>[System Bus Policy]</title>
            <para>
                If the <option>sockets</option> key is not allowing full access
                to the D-Bus system bus, then flatpak does not make the system
                bus available unless the [System Bus Policy] group is present
                and provides a policy for filtered access. Available since 0.2.
            </para>
            <para>
                Entries in this group have the same form as for the [Session Bus Policy] group.
                However, the app has no permissions by default.
            </para>
        </refsect2>
        <refsect2>
            <title>[Environment]</title>
            <para>
                The [Environment] group specifies environment variables to set
                when running the application. Available since 0.3.
            </para>
            <para>
                Entries in this group have the form <option>VAR=VALUE</option>
                where <option>VAR</option> is the name of an environment variable
                to set.
            </para>
            <para>
                Note that environment variables can also be unset (removed
                from the environment) by listing them in the
                <option>unset-environment</option> entry of the
                [Context] group.
              </para>
        </refsect2>
        <refsect2>
            <title>[Extension NAME]</title>
            <para>
                Runtimes and applications can define extension points, which allow
                optional, additional runtimes to be mounted at a specified location
                inside the sandbox when they are present on the system. Typical uses
                for extension points include translations for applications, or debuginfo
                for sdks. The name of the extension point is specified as part of the
                group heading. Since 0.11.4, the name may optionally include a tag
                in the NAME in the name@tag ref syntax if you wish to use different
                configurations (eg, versions) of the same extension concurrently.
                The "tag" is effectively ignored, but is necessary in order to allow
                the same extension name to be specified more than once.
            </para>
            <variablelist>
                <varlistentry>
                    <term><option>directory</option> (string)</term>
                    <listitem><para>
                        The relative path at which the extension will be mounted in
                        the sandbox. If the extension point is for an application, the
                        path is relative to <filename>/app</filename>, otherwise
                        it is relative to <filename>/usr</filename>. This key
                        is mandatory. Available since 0.1.
                    </para></listitem>
                </varlistentry>
                <varlistentry>
                    <term><option>version</option> (string)</term>
                    <listitem><para>
                        The branch to use when looking for the extension. If this is
                        not specified, it defaults to the branch of the application or
                        runtime that the extension point is for.
                        Available since 0.4.1.
                    </para></listitem>
                </varlistentry>
                <varlistentry>
                    <term><option>versions</option> (string)</term>
                    <listitem><para>
                        The branches to use when looking for the extension. If this is
                        not specified, it defaults to the branch of the application or
                        runtime that the extension point is for. Available since
                        0.9.1, and backported to the 0.8.x branch in 0.8.4.
                    </para></listitem>
                </varlistentry>
                <varlistentry>
                    <term><option>add-ld-path</option> (string)</term>
                    <listitem><para>
                        A path relative to the extension point directory that will be appended
                        to LD_LIBRARY_PATH. Available since 0.9.1, and
                        backported to the 0.8.x branch in 0.8.3.
                    </para></listitem>
                </varlistentry>
                <varlistentry>
                    <term><option>merge-dirs</option> (string)</term>
                    <listitem><para>
                        A list of relative paths of directories below the extension point directory
                        that will be merged. Available since 0.9.1, and
                        backported to the 0.8.x branch in 0.8.3.
                    </para></listitem>
                </varlistentry>
                <varlistentry>
                    <term><option>download-if</option> (string)</term>
                    <listitem>
                        <para>
                            A condition that must be true for the extension to be auto-downloaded.
                            As of 1.1.1 this supports multiple conditions separated by semi-colons.
                        </para>
                        <para>
                            These are the supported conditions:
                        </para>
                        <variablelist>
                            <varlistentry>
                                <term><option>active-gl-driver</option></term>
                                <para>
                                    Is true if the name of the active GL driver matches the
                                    extension point basename. Available since 0.9.1, and backported to
                                    the 0.8.x branch in 0.8.3.
                                </para>
                            </varlistentry>
                            <varlistentry>
                                <term><option>active-gtk-theme</option></term>
                                <para>
                                    Is true if the name of the current GTK theme
                                    (via org.gnome.desktop.interface GSetting) matches the extension point
                                    basename. Added 0.10.1.
                                </para>
                            </varlistentry>
                            <varlistentry>
                                <term><option>have-intel-gpu</option></term>
                                <para>Is true if the i915 kernel module is loaded. Added 0.10.1.</para>
                            </varlistentry>
                            <varlistentry>
                                <term><option>have-kernel-module-*</option></term>
                                <para>
                                    Is true if the suffix (case-sensitive) is found in <literal>/proc/modules</literal>.
                                    For example <literal>have-kernel-module-nvidia</literal>.
                                    Added 1.13.1.
                                </para>
                            </varlistentry>
                            <varlistentry>
                                <term><option>on-xdg-desktop-*</option></term>
                                <para>
                                    Is true if the suffix (case-insensitively) is in the
                                    <literal>XDG_CURRENT_DESKTOP</literal> env var.
                                    For example <literal>on-xdg-desktop-GNOME-classic</literal>.
                                    Added 1.1.1.
                                </para>
                            </varlistentry>
                        </variablelist>
                    </listitem>
                </varlistentry>
                <varlistentry>
                    <term><option>autoprune-unless</option> (string)</term>
                    <listitem><para>
                        A condition that must be false for the extension to be considered unused when
                        pruning. For example, <command>flatpak uninstall --unused</command> uses
                        this information. The only currently recognized value is active-gl-driver,
                        which is true if the name of the active GL driver matches the extension
                        point basename. Available since 0.11.8.
                    </para></listitem>
                </varlistentry>
                <varlistentry>
                    <term><option>enable-if</option> (string)</term>
                    <listitem><para>
                        A condition that must be true for the extension to be enabled.
                        As of 1.1.1 this supports multiple conditions separated by semi-colons.
                        See <option>download-if</option> for available conditions.
                    </para></listitem>
                </varlistentry>
                <varlistentry>
                    <term><option>subdirectory-suffix</option> (string)</term>
                    <listitem><para>
                        A suffix that gets appended to the directory name. This is very
                        useful when the extension point naming scheme is "reversed". For example,
                        an extension point for GTK+ themes would be /usr/share/themes/$NAME/gtk-3.0,
                        which could be achieved using subdirectory-suffix=gtk-3.0.
                        Available since 0.9.1, and backported to the 0.8.x
                        branch in 0.8.3.
                    </para></listitem>
                </varlistentry>
                <varlistentry>
                    <term><option>subdirectories</option> (boolean)</term>
                    <listitem><para>
                        If this key is set to true, then flatpak will look for
                        extensions whose name is a prefix of the extension point name, and
                        mount them at the corresponding name below the subdirectory.
                        Available since 0.1.
                    </para></listitem>
                </varlistentry>
                <varlistentry>
                    <term><option>no-autodownload</option> (boolean)</term>
                    <listitem><para>
                        Whether to automatically download extensions matching this extension
                        point when updating or installing a 'related' application or runtime.
                        Available since 0.6.7.
                    </para></listitem>
                </varlistentry>
                <varlistentry>
                    <term><option>locale-subset</option> (boolean)</term>
                    <listitem><para>
                        If set, then the extensions are partially downloaded by default,
                        based on the currently configured locales. This means that the extension
                        contents should be a set of directories with the language code as name.
                        Available since 0.9.13 (and 0.6.6 for any extensions called *.Locale)
                    </para></listitem>
                </varlistentry>
                <varlistentry>
                    <term><option>autodelete</option> (boolean)</term>
                    <listitem><para>
                        Whether to automatically delete extensions matching this extension
                        point when deleting a 'related' application or runtime.
                        Available since 0.6.7.
                    </para></listitem>
                </varlistentry>
                <varlistentry>
                    <term><option>collection-id</option> (string)</term>
                    <listitem><para>
                        The ID of the collection that this extension point belongs to. If this
                        is unspecified, it defaults to the collection ID of the application
                        or runtime that the extension point is for.
                        Currently, extension points must be in the same collection as the
                        application or runtime that they are for.
                        Available since 0.99.1.
                    </para></listitem>
                </varlistentry>
            </variablelist>
        </refsect2>
        <refsect2>
            <title>[ExtensionOf]</title>
            <para>
                This optional group may be present if the runtime is an extension.
            </para>
            <variablelist>
                <varlistentry>
                    <term><option>ref</option> (string)</term>
                    <listitem><para>
                        The ref of the runtime or application that this extension
                        belongs to. Available since 0.9.1.
                    </para></listitem>
                </varlistentry>
                <varlistentry>
                    <term><option>runtime</option> (string)</term>
                    <listitem><para>
                        The runtime this extension will be inside of. If it is an
                        app extension, this is the app's runtime; otherwise, this
                        is identical to ref, without the runtime/ prefix.
                        Available since 1.5.0.
                    </para></listitem>
                </varlistentry>
                <varlistentry>
                    <term><option>priority</option> (integer)</term>
                    <listitem><para>
                        The priority to give this extension when looking for the
                        best match. Default is 0. Available since 0.9.1, and
                        backported to the 0.8.x branch in 0.8.3.
                    </para></listitem>
                </varlistentry>
                <varlistentry>
                    <term><option>tag</option> (string)</term>
                    <listitem><para>
                        The tag name to use when searching for this extension's mount
                        point in the parent flatpak. Available since 0.11.4.
                    </para></listitem>
                </varlistentry>
            </variablelist>
        </refsect2>
        <refsect2>
            <title>[Extra Data]</title>
            <para>
                This optional group may be present if the runtime or application uses
                extra data that gets downloaded separately. The data in this group
                gets merged into the repository summary, with the xa.extra-data-sources
                key.
            </para>
            <para>
                If multiple extra data sources are present, their uri, size and checksum
                keys are grouped together by using the same suffix. If only one extra
                data source is present, the suffix can be omitted.
            </para>
            <variablelist>
                <varlistentry>
                    <term><option>NoRuntime</option> (boolean)</term>
                    <listitem><para>
                        Whether to mount the runtime while running the /app/bin/apply_extra
                        script. Defaults to true, i.e. not mounting the runtime.
                        Available since 0.9.1, and backported to the 0.8.x
                        branch in 0.8.4.
                    </para></listitem>
                </varlistentry>
                <varlistentry>
                    <term><option>uri<replaceable>X</replaceable></option> (string)</term>
                    <listitem><para>
                        The uri for extra data source
                        <replaceable>X</replaceable>. The only supported uri
                        schemes are http and https. Available since 0.6.13.
                    </para></listitem>
                </varlistentry>
                <varlistentry>
                    <term><option>size<replaceable>X</replaceable></option> (integer)</term>
                    <listitem><para>
                        The size for extra data source
                        <replaceable>X</replaceable>. Available since 0.6.13.
                    </para></listitem>
                </varlistentry>
                <varlistentry>
                    <term><option>checksum<replaceable>X</replaceable></option> (string)</term>
                    <listitem><para>
                        The sha256 sum for extra data source
                        <replaceable>X</replaceable>. Available since 0.6.13.
                    </para></listitem>
                </varlistentry>
            </variablelist>
        </refsect2>
        <refsect2>
          <title>[Policy SUBSYSTEM]</title>
          <para>
            Subsystems can define their own policies to be placed in a group
            whose name has this form. Their values are treated as lists,
            in which items can have their meaning negated by prepending !
            to the value. They are not otherwise parsed by Flatpak.
            Available since 0.6.13.
            <!-- TODO: More information would be nice -->
          </para>
        </refsect2>
    </refsect1>

    <refsect1>
        <title>Example</title>
<programlisting>
[Application]
name=org.gnome.Calculator
runtime=org.gnome.Platform/x86_64/3.20
sdk=org.gnome.Sdk/x86_64/3.20
command=gnome-calculator

[Context]
shared=network;ipc;
sockets=x11;wayland;
filesystems=xdg-run/dconf;~/.config/dconf:ro;

[Session Bus Policy]
ca.desrt.dconf=talk

[Environment]
DCONF_USER_CONFIG_DIR=.config/dconf

[Extension org.gnome.Calculator.Locale]
directory=share/runtime/locale
subdirectories=true

[Extension org.gnome.Calculator.Debug]
directory=lib/debug
</programlisting>
    </refsect1>

    <refsect1>
        <title>See also</title>

        <para>
            <citerefentry><refentrytitle>flatpak</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
            <citerefentry><refentrytitle>flatpak-run</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
            <citerefentry><refentrytitle>flatpak-override</refentrytitle><manvolnum>1</manvolnum></citerefentry>
        </para>

    </refsect1>

</refentry>