mpv/DOCS/man/ipc.rst

JSON IPC
========

mpv can be controlled by external programs using the JSON-based IPC protocol. It
can be enabled by specifying the path to a unix socket using the option
``--input-unix-socket``. Clients can connect to this socket and send commands to
the player or receive events from it. You can use the ``socat`` tool to send
commands (and receive reply) from the shell.

.. warning::

    This is not intended to be a secure network protocol. It is explicitly
    insecure: there is no authentication, no encryption, and the commands
    themselves are insecure too. For example, the ``run`` command is exposed,
    which can run arbitrary system commands. The use-case is controlling the
    player locally. This is not different from the MPlayer slave protocol.

Protocol
--------

Clients can execute commands on the player by sending JSON messages of the
following form:

::

    { "command": ["command_name", "param1", "param2", ...] }

where ``command_name`` is the name of the command to be executed, followed by a
list of parameters. Parameters must be formatted as native JSON values
(integers, strings, booleans, ...). Every message **must** be terminated with
``\n``. Additionally, ``\n`` must not appear anywhere inside the message. In
practice this means that messages should be minified before being sent to mpv.

mpv will then send back a reply indicating whether the command was run
correctly, and an additional field holding the command-specific return data (it
can also be null).

::

    { "error": "success", "data": null }

mpv will also send events to clients with JSON messages of the following form:

::

    { "event": "event_name" }

where ``event_name`` is the name of the event. Additional event-specific fields
can also be present. See `List of events`_ for a list of all supported events.

If the first character (after skipping whitespace) is not ``{``, the command
will be interpreted as non-JSON text command, as they are used in input.conf
(or ``mpv_command_string()`` in the client API). Additionally, line starting
with ``#`` and empty lines are ignored.

Currently, embedded 0 bytes terminate the current line, but you should not
rely on this.

Commands
--------

Additionally to  the commands described in `List of Input Commands`_, a few
extra commands can also be used as part of the protocol:

``client_name``
    Return the name of the client as string. This is the string ``ipc-N`` with
    N being an integer number.

``get_time_us``
    Return the current mpv internal time in microseconds as a number. This is
    basically the system time, with an arbitrary offset.

``get_property``
    Return the value of the given property. The value will be sent in the data
    field of the replay message.

    Example:

    ::

        { "command": ["get_property", "volume"] }
        { "data": 50.0, "error": "success" }

``get_property_string``
    Like ``get_property``, but the resulting data will always be a string.

    Example:

    ::

        { "command": ["get_property_string", "volume"] }
        { "data": "50.000000", "error": "success" }

``set_property``
    Set the given property to the given value. See `Properties`_ for more
    information about properties.

    Example:

    ::

        { "command": ["set_property", "pause", true] }
        { "error": "success" }

``set_property_string``
    Like ``set_property``, but the argument value must be passed as string.

    Example:

    ::

        { "command": ["set_property_string", "pause", "yes"] }
        { "error": "success" }

``observe_property``
    Watch a property for changes. If the given property is changed, then an
    event of type ``property-change`` will be generated

    Example:

    ::

        { "command": ["observe_property", 1, "volume"] }
        { "error": "success" }
        { "event": "property-change", "id": 1, "data": 52.0, "name": "volume" }

``observe_property_string``
    Like ``observe_property``, but the resulting data will always be a string.

    Example:

    ::

        { "command": ["observe_property_string", 1, "volume"] }
        { "error": "success" }
        { "event": "property-change", "id": 1, "data": "52.000000", "name": "volume" }

``unobserve_property``
    Undo ``observe_property`` or ``observe_property_string``. This requires the
    numeric id passed to the observe command as argument.

    Example:

    ::

        { "command": ["unobserve_property", 1] }
        { "error": "success" }

``suspend``
    Suspend the mpv main loop. There is a long-winded explanation of this in
    the C API function ``mpv_suspend()``. In short, this prevents the player
    from displaying the next video frame, so that you don't get blocked when
    trying to access the player.

``resume``
    Undo one ``suspend`` call. ``suspend`` increments an internal counter, and
    ``resume`` decrements it. When 0 is reached, the player is actually resumed.

``get_version``
    Returns the client API version the C API of the remote mpv instance
    provides. (Also see ``DOCS/client-api-changes.rst``.)

UTF-8
-----

Normally, all strings are in UTF-8. Sometimes it can happen that strings are
in some broken encoding (often happens with file tags and such, and filenames
on many Unixes are not required to be in UTF-8 either). This means that mpv
sometimes sends invalid JSON. If that is a problem for the client application's
parser, it should filter the raw data for invalid UTF-8 sequences and perform
the desired replacement, before feeding the data to its JSON parser.

mpv will not attempt to construct invalid UTF-8 with broken escape sequences.