The metadata file is using the same .ini file format that is used
    for systemd unit files or application .desktop files.
[Application] or [Runtime]¶
Metadata for applications starts with an [Application] group,
    metadata for runtimes with a [Runtime] group.
The following keys can be present in these groups:
name (string)
The name of the application or runtime. This key is
  mandatory.
runtime (string)
The fully qualified name of the runtime that is used by
  the application. This key is mandatory for applications.
sdk (string)
The fully qualified name of the sdk that matches the
  runtime. Available since 0.1.
command (string)
The command to run. Only relevant for applications.
  Available since 0.1.
required-flatpak (string list)
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.
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 1.6.0;1.4.4;. Note
    that older versions of flatpak will just use the first element in the list,
    so make that the largest version.
tags (string list)
Tags to include in AppStream XML. Typical values in use
  on Flathub include beta, stable, proprietary and
  upstream-maintained. Available since 0.4.12.
[Context]¶
This group determines various system resources that may be shared
    with the application when it is run in a flatpak sandbox.
All keys in this group (and the group itself) are optional.
shared (list)
List of subsystems to share with the host system.
  Possible subsystems: network, ipc. Available since 0.3.
sockets (list)
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.
devices (list)
List of devices to make available in the sandbox.
  Possible values:
dri
Graphics direct rendering (/dev/dri). Available since
  0.3.
kvm
Virtualization (/dev/kvm). Available since 0.6.12.
all
All device nodes in /dev, but not /dev/shm (which is
  separately specified). Available since 0.6.6.
shm
Access to the host /dev/shm (/dev/shm). Available since
  1.6.1.
filesystems (list)
List of filesystem subsets to make available to the
  application. Possible values:
home
The entire home directory. Available since 0.3.
home/path
Alias for ~/path Available since 1.10. For better
  compatibility with older Flatpak versions, prefer to write this as
  ~/path.
host
The entire host file system, except for directories that
  are handled specially by Flatpak. In particular, this shares /home, /media,
  /opt, /run/media and /srv if they exist.
/dev is not shared: use devices=all; instead.
Parts of /sys are always shared. This option does not make
    additional files in /sys available.
Additionally, this keyword provides all of the same directories in
    /run/host as the host-os and host-etc keywords. If this
    keyword is used in conjunction with one of the host- keywords,
    whichever access level is higher (more permissive) will be used for the
    directories in /run/host: for example, host:rw;host-os:ro; is equivalent to
    host:rw;.
These other reserved directories are currently excluded: /app,
    /bin, /boot, /etc, /lib, /lib32, /lib64, /proc, /root, /run, /sbin, /tmp,
    /usr, /var.
Available since 0.3.
host-os
The host operating system's libraries, executables and
  static data from /usr and the related directories /bin, /lib, /lib32, /lib64,
  /sbin. Additionally, this keyword provides access to a subset of /etc that is
  associated with packaged libraries and executables, even if the
  
host-etc keyword was not used: /etc/ld.so.cache, (used by the dynamic
  linker) and /etc/alternatives (on operating systems that use it, such as
  Debian).
To avoid conflicting with the Flatpak runtime, these are mounted
    in the sandbox at /run/host/usr, /run/host/etc/ld.so.cache and so on.
Available since 1.7.
host-etc
The host operating system's configuration from /etc.
To avoid conflicting with the Flatpak runtime, this is mounted in
    the sandbox at /run/host/etc.
Available since 1.7.
xdg-desktop, xdg-documents, xdg-download,
    xdg-music, xdg-pictures, xdg-public-share,
    xdg-videos, xdg-templates
freedesktop.org special directories[1]. Available
  since 0.3.
xdg-desktop/path,
    xdg-documents/path, etc.
Subdirectories of freedesktop.org special directories.
  Available since 0.4.13.
xdg-cache, xdg-config, xdg-data
Directories defined by the freedesktop.org Base
  Directory Specification[2]. Available since 0.6.14.
xdg-cache/path,
    xdg-config/path, xdg-data/path
Subdirectories of directories defined by the
  freedesktop.org Base Directory Specification. Available since 0.6.14.
xdg-run/path
Subdirectories of the XDG_RUNTIME_DIR defined by
  the freedesktop.org Base Directory Specification. Note that xdg-run on
  its own is not supported. Available since 0.4.13.
/path
An arbitrary absolute path. Available since 0.3.
~/path
An arbitrary path relative to the home directory.
  Available since 0.3.
~
The same as home. Available since 1.10. For better
  compatibility with older Flatpak versions, prefer to write this as
  home.
One of the above followed by :ro
Make the given directory available read-only.
One of the above followed by :rw
Make the given directory available read/write. This is
  the default.
One of the above followed by :create
Make the given directory available read/write, and create
  it if it does not already exist.
persistent (list)
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.
features (list)
List of features available or unavailable to the
  application, currently from the following list:
devel
Allow system calls used by development-oriented tools
  such as perf, strace and gdb. Available since
  0.6.10.
multiarch
Allow running multilib/multiarch binaries, for example
  i386 binaries in an x86_64 environment. Available since 0.6.12.
bluetooth
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.
canbus
Allow the application to use canbus (AF_CAN) sockets.
  Note, for this work you must also have network access. Available since
  1.0.3.
A feature can be prefixed with ! to indicate the absence of
    that feature, for example !devel if development and debugging are not
    allowed.
unset-environment (list)
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.
[Instance]¶
This group only appears in /.flatpak-info for a running app, and
    not in the metadata files written by application authors. It is filled in by
    Flatpak itself.
instance-id (string)
The ID of the running instance. This number is used as
  the name of the directory in XDG_RUNTIME_DIR/.flatpak where Flatpak
  stores information about this instance.
instance-path (string)
The absolute path on the host system of the app's
  persistent storage area in $HOME/.var.
app-path (string)
The absolute path on the host system of the app's app
  files, as mounted at /app inside the container. Available since 0.6.10.
app-commit (string)
The commit ID of the application that is running.
app-extensions (list of strings)
A list of app extensions that are mounted into the
  running instance. The format for each list item is
  EXTENSION_ID=COMMIT.
branch (string)
The branch of the app, for example stable. Available
  since 0.6.10.
arch (string)
The architecture of the running instance.
flatpak-version (string)
The version number of the Flatpak version that ran this
  app. Available since 0.6.11.
runtime-path (string)
The absolute path on the host system of the app's runtime
  files, as mounted at /usr inside the container. Available since 0.6.10.
runtime-commit (string)
The commit ID of the runtime that is used.
runtime-extensions (list of strings)
A list of runtime extensions that are mounted into the
  running instance. The format for each list item is
  EXTENSION_ID=COMMIT.
extra-args (string)
Extra arguments that were passed to flatpak run.
sandbox (boolean)
Whether the --sandbox option was passed to flatpak
  run.
build (boolean)
Whether this instance was created by flatpak build.
session-bus-proxy (boolean)
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.
system-bus-proxy (boolean)
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.
[Session Bus Policy]¶
If the sockets key is not allowing full access to the D-Bus
    session bus, then flatpak provides filtered access.
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.*).
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.
If the [Session Bus Policy] group is present, it provides policy
    for session bus access.
Each key in this group has the form of a D-Bus bus name or prefix
    thereof, for example org.gnome.SessionManager or
    org.freedesktop.portal.*
The possible values for entry are, in increasing order or
  access:
none
The bus name or names in question is invisible to the
  application. Available since 0.2.
see
The bus name or names can be enumerated by the
  application. Available since 0.2.
talk
The application can send messages/ and receive replies
  and signals from the bus name or names. Available since 0.2.
own
The application can own the bus name or names (as well as
  all the above). Available since 0.2.
[System Bus Policy]¶
If the sockets 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.
Entries in this group have the same form as for the [Session Bus
    Policy] group. However, the app has no permissions by default.
[Environment]¶
The [Environment] group specifies environment variables to set
    when running the application. Available since 0.3.
Entries in this group have the form VAR=VALUE where
    VAR is the name of an environment variable to set.
Note that environment variables can also be unset (removed from
    the environment) by listing them in the unset-environment entry of
    the [Context] group.
[Extension NAME]¶
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.
directory (string)
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 /app, otherwise it is relative to /usr. This key is mandatory.
  Available since 0.1.
version (string)
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.
versions (string)
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.
add-ld-path (string)
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.
merge-dirs (string)
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.
download-if (string)
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.
These are the supported conditions:
active-gl-driver
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.
active-gtk-theme
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.
have-intel-gpu
Is true if the i915 kernel module is loaded. Added
  0.10.1.
on-xdg-desktop-*
Is true if the suffix (case-insensitively) is in the
  XDG_CURRENT_DESKTOP env var. For example on-xdg-desktop-GNOME-classic. Added
  1.1.1.
autoprune-unless (string)
A condition that must be false for the extension to be
  considered unused when pruning. For example, flatpak uninstall --unused
  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.
enable-if (string)
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 download-if for available conditions.
subdirectory-suffix (string)
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.
subdirectories (boolean)
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.
no-autodownload (boolean)
Whether to automatically download extensions matching
  this extension point when updating or installing a 'related' application or
  runtime. Available since 0.6.7.
locale-subset (boolean)
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)
autodelete (boolean)
Whether to automatically delete extensions matching this
  extension point when deleting a 'related' application or runtime. Available
  since 0.6.7.
collection-id (string)
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.
[ExtensionOf]¶
This optional group may be present if the runtime is an
  extension.
ref (string)
The ref of the runtime or application that this extension
  belongs to. Available since 0.9.1.
runtime (string)
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.
priority (integer)
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.
tag (string)
The tag name to use when searching for this extension's
  mount point in the parent flatpak. Available since 0.11.4.
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.
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.
NoRuntime (boolean)
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.
uriX (string)
The uri for extra data source X. The only
  supported uri schemes are http and https. Available since 0.6.13.
sizeX (integer)
The size for extra data source X. Available since
  0.6.13.
checksumX (string)
The sha256 sum for extra data source X. Available
  since 0.6.13.
[Policy SUBSYSTEM]¶
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.