The Music Player Daemon protocolGeneral protocol syntaxProtocol overview
The MPD command protocol exchanges
line-based text records between client and server over TCP.
Once the client is connected to the server, they conduct a
conversation until the client closes the connection. The
conversation flow is always initiated by the client.
The client transmits a command sequence, terminated by the
newline character \n. The server will
respond with one or more lines, the last of which will be a
completion code.
When the client connects to the server, the server will answer
with the following line:
OK MPD version
where version is a version identifier such as
0.12.2. This version identifier is the version of the protocol
spoken, not the real version of the daemon. (There is no way to
retrieve this real version identifier from the connection.)
RequestsCOMMANDARG
If arguments contain spaces, they should be surrounded by double
quotation marks.
Argument strings are separated from the command and any other
arguments by linear white-space (' ' or '\t').
All data between the client and the server is encoded in
UTF-8. (Note: In UTF-8 all standard ansi characters, 0-127 are
the same as in standard ansi encoding. Also, no ansi character
appears in any multi-byte characters. So, you can use
standard C functions like strlen, and
strcpy just fine with UTF-8 encoded
strings. For example: OK encoded in
UTF-8 is simply OK. For more
information on UTF-8:
)
Responses
A command returns OK on completion or
ACK some error on failure. These
denote the end of command execution.
Failure responses
The nature of the error can be gleaned from the information
that follows the ACK.
ACK lines are of the form:
ACK [error@command_listNum] {current_command} message_text\n
These responses are generated by a call to
commandError. They contain four separate
terms. Let's look at each of them:
error: numeric value of one
of the ACK_ERROR constants defined
in ack.h.
command_listNum:
offset of the command that caused the error in a Command List.
An error will always cause a command list to terminate
at the command that causes the error.
current_command:
name of the command, in a Command List,
that was executing when the error occurred.
message_text:
some (hopefully) informative text that describes the
nature of the error.
foo
An example might help. Consider the following sequence
sent from the client to the server.
command_list_begin
volume 86
play 10240
status
command_list_end
The server responds with:
ACK [50@1] {play} song doesn't exist: "10240"
This tells us that the play command, which was the
second in the list (the first or only command is
numbered 0), failed with error 50. The number 50
translates to ACK_ERROR_NO_EXIST--the
song doesn't exist. This is reiterated by the message text
which also tells us which song doesn't exist.
Command lists
To facilitate faster adding of files etc. you can pass a list
of commands all at once using a command list. The command
list begins with command_list_begin or
command_list_ok_begin and ends with
command_list_end.
It does not execute any commands until the list has ended.
The return value is whatever the return for a list of commands
is. On success for all commands,
OK is returned. If a command
fails, no more commands are executed and the appropriate
ACK error is returned. If
command_list_ok_begin is used,
list_OK is returned for each
successful command executed in the command list.
Ranges
Some commands (e.g. delete)
allow specifying a range in the form
START:END (the END
item is not included in the range, similar to ranges in the
Python programming language). If END is
omitted, then the maximum possible value is assumed.
Tags
The following tags are supported by
MPD:
There can be multiple values for some of these tags. For
example, MPD may return multiple
lines with a performer tag. A tag value is
a UTF-8 string.
RecipesQueuing
Often, users run MPD with "random" enabled, but want to
be able to insert songs "before" the rest of the playlist.
That is commonly called "queuing".
MPD implements this by allowing the client to specify a
"priority" for each song in the playlist (commands prio and
prioid). A
higher priority means that the song is going to be played
before the other songs.
In "random" mode, MPD maintains an
internal randomized sequence of songs. In this sequence,
songs with a higher priority come first, and all songs with
the same priority are shuffled (by default, all songs are
shuffled, because all have the same priority "0"). When you
increase the priority of a song, it is moved to the front of
the sequence according to its new priority, but always after
the current one. A song that has been played already (it's
"before" the current song in that sequence) will only be
scheduled for repeated playback if its priority has become
bigger than the priority of the current song. Decreasing the
priority of a song will move it farther to the end of the
sequence. Changing the priority of the current song has no
effect on the sequence. During playback, a song's priority is
reset to zero.
Command reference
For manipulating playlists and playing, there are two sets of
commands. One set uses the song id of a song in the playlist,
while another set uses the playlist position of the song. The
commands using song ids should be used instead of the commands
that manipulate and control playback based on playlist
position. Using song ids is a safer method when multiple
clients are interacting with MPD.
Querying MPD's statusclearerror
Clears the current error message in status (this is also
accomplished by any command that starts playback).
currentsong
Displays the song info of the current song (same song that
is identified in status).
idleSUBSYSTEMSIntroduced with
MPD 0.14
Waits until there is a noteworthy change in one or more
of MPD's subsystems. As soon
as there is one, it lists all changed systems in a line
in the format changed:
SUBSYSTEM, where SUBSYSTEM is one of the
following:
database: the song database
has been modified after update.
update: a database update
has started or finished. If the database was
modified during the update, the
database event is also
emitted.
stored_playlist: a stored
playlist has been modified, renamed, created or
deleted
playlist: the current
playlist has been modified
player: the player has been
started, stopped or seeked
mixer: the volume has been
changed
output: an audio output has
been enabled or disabled
options: options like
, ,
, replay gain
sticker: the sticker database
has been modified.
subscription: a client
has subscribed or unsubscribed to a channel
message: a message was
received on a channel this client is subscribed to;
this event is only emitted when the queue is empty
While a client is waiting for idle
results, the server disables timeouts, allowing a client
to wait for events as long as mpd runs. The
idle command can be canceled by
sending the command noidle (no other
commands are allowed). MPD
will then leave idle mode and print
results immediately; might be empty at this time.
If the optional SUBSYSTEMS argument
is used, MPD will only send
notifications when something changed in one of the
specified subsytems.
status
Reports the current status of the player and the volume
level.
volume:
0-100repeat:
0 or 1random:
0 or 1single:
Introduced with MPD 0.150 or 1consume:
0 or 1playlist:
31-bit unsigned integer, the playlist
version numberplaylistlength:
integer, the length of the
playliststate:
play, stop, or pausesong:
playlist song number of the current
song stopped on or playing
songid:
playlist songid of the current song
stopped on or playing
nextsong:
playlist song number of the next
song to be played
nextsongid:
playlist songid of the next song
to be played
time:
total time elapsed (of current
playing/paused song)elapsed:
Introduced with MPD 0.16
Total time elapsed within the current song, but
with higher resolution.
duration:
Introduced with MPD 0.20
Duration of the current song in seconds.
bitrate:
instantaneous bitrate in
kbpsxfade:
crossfade in secondsmixrampdb:
mixramp threshold in dBmixrampdelay:
mixrampdelay in secondsaudio:
The format emitted by the decoder plugin during
playback, format:
"samplerate:bits:channels".
Check the user manual for a detailed explanation.
updating_db:
job iderror:
if there is an error, returns message
herestats
Displays statistics.
artists: number of artists
albums: number of albums
songs: number of songs
uptime: daemon uptime in seconds
db_playtime: sum of all song
times in the db
db_update: last db update in UNIX
time
playtime: time length of music played
Playback optionsconsumeSTATE
Sets consume state to STATE,
STATE should be 0 or 1.
When consume is activated, each song played is removed from playlist.
crossfadeSECONDS
Sets crossfading between songs.
mixrampdbdeciBels
Sets the threshold at which songs will be overlapped. Like crossfading but doesn't fade the track volume, just overlaps. The songs need to have MixRamp tags added by an external tool. 0dB is the normalized maximum volume so use negative values, I prefer -17dB. In the absence of mixramp tags crossfading will be used. See http://sourceforge.net/projects/mixramp
mixrampdelaySECONDS
Additional time subtracted from the overlap calculated by mixrampdb. A value of "nan" disables MixRamp overlapping and falls back to crossfading.
randomSTATE
Sets random state to STATE,
STATE should be 0 or 1.
repeatSTATE
Sets repeat state to STATE,
STATE should be 0 or 1.
setvolVOL
Sets volume to VOL, the range of
volume is 0-100.
singleSTATE
Sets single state to STATE,
STATE should be 0 or 1.
When single is activated, playback is stopped after current song, or
song is repeated if the 'repeat' mode is enabled.
replay_gain_modeMODE
Sets the replay gain mode. One of
off,
track,
album,
autoadded in MPD 0.16.
Changing the mode during playback may take several
seconds, because the new settings does not affect the
buffered data.
This command triggers the
options idle event.
replay_gain_status
Prints replay gain options. Currently, only the
variable replay_gain_mode is
returned.
volumeCHANGE
Changes volume by amount CHANGE.
volume is deprecated, use
setvol instead.
Controlling playbacknext
Plays next song in the playlist.
pausePAUSE
Toggles pause/resumes playing, PAUSE is 0 or 1.
The use of pause command w/o the PAUSE argument is
deprecated.
playSONGPOS
Begins playing the playlist at song number
SONGPOS.
playidSONGID
Begins playing the playlist at song
SONGID.
previous
Plays previous song in the playlist.
seekSONGPOSTIME
Seeks to the position TIME (in
seconds; fractions allowed) of entry
SONGPOS in the playlist.
seekidSONGIDTIME
Seeks to the position TIME (in
seconds; fractions allowed) of song
SONGID.
seekcurTIME
Seeks to the position TIME (in
seconds; fractions allowed) within the current song. If
prefixed by '+' or '-', then the time is relative to the
current playing position.
stop
Stops playing.
The current playlistaddURI
Adds the file URI to the playlist
(directories add recursively). URI
can also be a single file.
addidURIPOSITION
Adds a song to the playlist (non-recursive) and returns the song id.
URI is always a single file or
URL. For example:
addid "foo.mp3"
Id: 999
OK
clear
Clears the current playlist.
deletePOSSTART:END
Deletes a song from the playlist.
deleteidSONGID
Deletes the song SONGID from the
playlist
moveFROMSTART:ENDTO
Moves the song at FROM or range of songs
at START:END to TO
in the playlist.
Ranges are supported since MPD 0.15moveidFROMTO
Moves the song with FROM (songid) to
TO (playlist index) in the
playlist. If TO is negative, it
is relative to the current song in the playlist (if
there is one).
playlist
Displays the current playlist.
Do not use this, instead use playlistinfo.
playlistfindTAGNEEDLE
Finds songs in the current playlist with strict
matching.
playlistidSONGID
Displays a list of songs in the playlist.
SONGID is optional and specifies a
single song to display info for.
playlistinfoSONGPOSSTART:END
Displays a list of all songs in the playlist, or if the optional
argument is given, displays information only for the song
SONGPOS or the range of songs
START:ENDplaylistsearchTAGNEEDLE
Searches case-insensitively for partial matches in the
current playlist.
plchangesVERSIONSTART:END
Displays changed songs currently in the playlist since
VERSION. Start and end positions may
be given to limit the output to changes in the given
range.
To detect songs that were deleted at the end of the
playlist, use playlistlength returned by status command.
plchangesposidVERSIONSTART:END
Displays changed songs currently in the playlist since
VERSION. This function only
returns the position and the id of the changed song, not
the complete metadata. This is more bandwidth efficient.
To detect songs that were deleted at the end of the
playlist, use playlistlength returned by status command.
prioPRIORITYSTART:END
Set the priority of the specified songs. A higher
priority means that it will be played first when
"random" mode is enabled.
A priority is an integer between 0 and 255. The default
priority of new songs is 0.
prioidPRIORITYID
Same as prio,
but address the songs with their id.
rangeidIDSTART:ENDSince MPD
0.19 Specifies the portion of the
song that shall be played. START and
END are offsets in seconds
(fractional seconds allowed); both are optional.
Omitting both (i.e. sending just ":") means "remove the
range, play everything". A song that is currently
playing cannot be manipulated this way.
shuffleSTART:END
Shuffles the current playlist.
START:END is optional and specifies
a range of songs.
swapSONG1SONG2
Swaps the positions of SONG1 and
SONG2.
swapidSONG1SONG2
Swaps the positions of SONG1 and
SONG2 (both song ids).
addtagidSONGIDTAGVALUE
Adds a tag to the specified song. Editing song tags is
only possible for remote songs. This change is
volatile: it may be overwritten by tags received from
the server, and the data is gone when the song gets
removed from the queue.
cleartagidSONGIDTAG
Removes tags from the specified song. If
TAG is not specified, then all tag
values will be removed. Editing song tags is only
possible for remote songs.
Stored playlists
Playlists are stored inside the configured playlist directory.
They are addressed with their file name (without the directory
and without the .m3u suffix).
Some of the commands described in this section can be used to
run playlist plugins instead of the hard-coded simple
m3u parser. They can access playlists in
the music directory (relative path including the suffix) or
remote playlists (absolute URI with a supported scheme).
listplaylistNAME
Lists the songs in the playlist. Playlist plugins are
supported.
listplaylistinfoNAME
Lists the songs with metadata in the playlist. Playlist
plugins are supported.
listplaylists
Prints a list of the playlist directory.
After each playlist name the server sends its last
modification time as attribute "Last-Modified" in ISO
8601 format. To avoid problems due to clock differences
between clients and the server, clients should not
compare this value with their local clock.
loadNAMESTART:END
Loads the playlist into the current queue. Playlist
plugins are supported. A range may be specified to load
only a part of the playlist.
playlistaddNAMEURI
Adds URI to the playlist
NAME.m3u.
NAME.m3u will be created if it does
not exist.
playlistclearNAME
Clears the playlist NAME.m3u.
playlistdeleteNAMESONGPOS
Deletes SONGPOS from the
playlist NAME.m3u.
playlistmoveNAMEFROMTO
Moves the song at position FROM in
the playlist NAME.m3u to the
position TO.
renameNAMENEW_NAME
Renames the playlist NAME.m3u to NEW_NAME.m3u.
rmNAME
Removes the playlist NAME.m3u from
the playlist directory.
saveNAME
Saves the current playlist to
NAME.m3u in the playlist directory.
The music databasecountTAGNEEDLE...groupGROUPTYPE
Counts the number of songs and their total playtime in
the db matching TAG exactly.
The group keyword may be used to
group the results by a tag. The following prints
per-artist counts:
count group artistfindTYPEWHAT...window START:END
Finds songs in the db that are exactly
WHAT. TYPE can
be any tag supported by MPD, or one of the special
parameters:
any checks all tag values
file checks the full path
(relative to the music directory)
base restricts the search to
songs in the given directory (also relative to the
music directory)
modified-since compares the
file's time stamp with the given value (ISO 8601 or
UNIX time stamp)
WHAT is what to find.
window can be used to query only a
portion of the real response. The parameter is two
zero-based record numbers; a start number and an end
number.
findaddTYPEWHAT...
Finds songs in the db that are exactly
WHAT and adds them to current playlist.
Parameters have the same meaning as for find.
listTYPEFILTERTYPEFILTERWHAT...groupGROUPTYPE...
Lists unique tags values of the specified type.
TYPE can be any tag supported by
MPD or
file.
Additional arguments may specify a filter like the one
in the find
command.
The group keyword may be used
(repeatedly) to group the results by one or more tags.
The following example lists all album names,
grouped by their respective (album) artist:
list album group albumartistlistallURI
Lists all songs and directories in
URI.
Do not use this command. Do not manage a client-side
copy of MPD's database. That
is fragile and adds huge overhead. It will break with
large databases. Instead, query
MPD whenever you need
something.
listallinfoURI
Same as listall, except it also
returns metadata info in the same format as
lsinfo.
Do not use this command. Do not manage a client-side
copy of MPD's database. That
is fragile and adds huge overhead. It will break with
large databases. Instead, query
MPD whenever you need
something.
listfilesURI
Lists the contents of the directory
URI, including files are not
recognized by MPD.
URI can be a path relative to the
music directory or an URI understood by one of the
storage plugins. The response contains at least one
line for each directory entry with the prefix "file: "
or "directory: ", and may be followed by file attributes
such as "Last-Modified" and "size".
For example, "smb://SERVER" returns a list of all shares
on the given SMB/CIFS server; "nfs://servername/path"
obtains a directory listing from the NFS server.
lsinfoURI
Lists the contents of the directory
URI.
When listing the root directory, this currently returns
the list of stored playlists. This behavior is
deprecated; use "listplaylists" instead.
This command may be used to list metadata of remote
files (e.g. URI beginning with "http://" or "smb://").
Clients that are connected via UNIX domain socket may
use this command to read the tags of an arbitrary local
file (URI is an absolute path).
readcommentsURI
Read "comments" (i.e. key-value pairs) from the file
specified by "URI". This "URI" can be a path relative
to the music directory or an absolute path.
This command may be used to list metadata of remote
files (e.g. URI beginning with "http://" or "smb://").
The response consists of lines in the form "KEY: VALUE".
Comments with suspicious characters (e.g. newlines) are
ignored silently.
The meaning of these depends on the codec, and not all
decoder plugins support it. For example, on Ogg files,
this lists the Vorbis comments.
searchTYPEWHAT...window START:END
Searches for any song that contains
WHAT. Parameters have the same meaning
as for find, except that search is not
case sensitive.
searchaddTYPEWHAT...
Searches for any song that contains WHAT
in tag TYPE and adds them to current playlist.
Parameters have the same meaning as for find,
except that search is not case sensitive.
searchaddplNAMETYPEWHAT...
Searches for any song that contains WHAT
in tag TYPE and adds them to the playlist
named NAME.
If a playlist by that name doesn't exist it is created.
Parameters have the same meaning as for find,
except that search is not case sensitive.
updateURI
Updates the music database: find new files, remove
deleted files, update modified files.
URI is a particular directory or
song/file to update. If you do not specify it,
everything is updated.
Prints "updating_db: JOBID" where
JOBID is a positive number
identifying the update job. You can read the current
job id in the status response.
rescanURI
Same as update, but also rescans
unmodified files.
Mounts and neighbors
A "storage" provides access to files in a directory tree. The
most basic storage plugin is the "local" storage plugin which
accesses the local file system, and there are plugins to
access NFS and SMB servers.
Multiple storages can be "mounted" together, similar to the
mount command on many operating
systems, but without cooperation from the kernel. No
superuser privileges are necessary, beause this mapping exists
only inside the MPD process
mountPATHURI
Mount the specified remote storage URI at the given
path. Example:
mount foo nfs://192.168.1.4/export/mp3unmountPATH
Unmounts the specified path. Example:
unmount foolistmounts
Queries a list of all mounts. By default, this contains
just the configured music_directory.
Example:
listmounts
mount:
storage: /home/foo/music
mount: foo
storage: nfs://192.168.1.4/export/mp3
OK
listneighbors
Queries a list of "neighbors" (e.g. accessible file
servers on the local net). Items on that list may be
used with the mount
command. Example:
listneighbors
neighbor: smb://FOO
name: FOO (Samba 4.1.11-Debian)
OK
Stickers
"Stickers" are pieces of
information attached to existing
MPD objects (e.g. song files,
directories, albums). Clients can create arbitrary name/value
pairs. MPD itself does not assume
any special meaning in them.
The goal is to allow clients to share additional (possibly
dynamic) information about songs, which is neither stored on
the client (not available to other clients), nor stored in the
song files (MPD has no write
access).
Client developers should create a standard for common sticker
names, to ensure interoperability.
Objects which may have stickers are addressed by their object
type ("song" for song objects) and their URI (the path within
the database for songs).
stickergetTYPEURINAME
Reads a sticker value for the specified object.
stickersetTYPEURINAMEVALUE
Adds a sticker value to the specified object. If a
sticker item with that name already exists, it is
replaced.
stickerdeleteTYPEURINAME
Deletes a sticker value from the specified object. If
you do not specify a sticker name, all sticker values
are deleted.
stickerlistTYPEURI
Lists the stickers for the specified object.
stickerfindTYPEURINAME
Searches the sticker database for stickers with the
specified name, below the specified directory (URI).
For each matching song, it prints the URI and that one
sticker's value.
stickerfindTYPEURINAME=VALUE
Searches for stickers with the given value.
Other supported operators are:
"<", ">"
Connection settingsclose
Closes the connection to MPD.
MPD will try to send the
remaining output buffer before it actually closes the
connection, but that cannot be guaranteed. This command
will not generate a response.
kill
Kills MPD.
passwordPASSWORD
This is used for authentication with the server.
PASSWORD is simply the plaintext
password.
ping
Does nothing but return "OK".
Audio output devicesdisableoutputID
Turns an output off.
enableoutputID
Turns an output on.
toggleoutputID
Turns an output on or off, depending on the current
state.
outputs
Shows information about all outputs.
outputid: 0
outputname: My ALSA Device
outputenabled: 0
OK
Return information:
outputid: ID of the output. May change between executions
outputname: Name of the output. It can be any.
outputenabled: Status of the output. 0 if disabled, 1 if enabled.
Reflectionconfig
Dumps configuration values that may be interesting for
the client. This command is only permitted to "local"
clients (connected via UNIX domain socket).
The following response attributes are available:
Name
Description
music_directory
The absolute path of the music directory.
commands
Shows which commands the current user has access to.
notcommands
Shows which commands the current user does not have
access to.
tagtypes
Shows a list of available song metadata.
urlhandlers
Gets a list of available URL handlers.
decoders
Print a list of decoder plugins, followed by their
supported suffixes and MIME types. Example response:
plugin: mad
suffix: mp3
suffix: mp2
mime_type: audio/mpeg
plugin: mpcdec
suffix: mpcClient to client
Clients can communicate with each others over "channels". A
channel is created by a client subscribing to it. More than
one client can be subscribed to a channel at a time; all of
them will receive the messages which get sent to it.
Each time a client subscribes or unsubscribes, the global idle
event subscription is generated. In
conjunction with the channels command, this
may be used to auto-detect clients providing additional
services.
New messages are indicated by the message
idle event.
subscribeNAME
Subscribe to a channel. The channel is created if it
does not exist already. The name may consist of
alphanumeric ASCII characters plus underscore, dash, dot
and colon.
unsubscribeNAME
Unsubscribe from a channel.
channels
Obtain a list of all channels. The response is a list
of "channel:" lines.
readmessages
Reads messages for this client. The response is a list
of "channel:" and "message:" lines.
sendmessageCHANNELTEXT
Send a message to the specified channel.