SYNCTHING-CONFIG(5)

NAME
syncthing-config - Syncthing Configuration

SYNOPSIS

$HOME/.config/syncthing
$HOME/Library/Application Support/Syncthing
%LOCALAPPDATA%/Syncthing

DESCRIPTION

Syncthing uses a single directory to store configuration, crypto keys and index caches. The location defaults to $HOME/.config/syncthing (Unix-like), $HOME/Library/Application Support/Syncthing (Mac), or %LOCALAPPDATA%/Syncthing (Windows). It can be changed at runtime using the -home flag. In this directory the following files are located:

config.xml
    The configuration file, in XML format.

cert.pem, key.pem
    The device’s ECDSA public and private key. These form the basis for the device ID. The key must be kept private.

https-cert.pem, https-key.pem
    The certificate and key for HTTPS GUI connections. These may be replaced with a custom certificate for HTTPS as desired.

index-*.db
    A directory holding the database with metadata and hashes of the files currently on disk and available from peers.

csrftokens.txt
    A list of recently issued CSRF tokens (for protection against browser cross site request forgery).

CONFIG FILE FORMAT

The following shows an example of the default configuration file (IDs will differ):

<configuration version="30">
    <folder id="default" label="Default Folder" path="/Users/jb/Sync/" type="sendreceive" rescanIntervalS="3600" fsWatcherEnabled="true" fsWatcherDelayS="10" ignorePerms="false" autoNormalize="true">
        <filesystemType>basic</filesystemType>
        <device id="3LT2GA5-CQI4XJM-WTZ264P-MLOGMHL-MCRLDNT-MZV4RD3-KA745CL-OGAERQZ"></device>
        <minDiskFree unit="%">1</minDiskFree>
        <versioning></versioning>
        <copiers>0</copiers>
        <pullerMaxPendingKiB>0</pullerMaxPendingKiB>
        <hashers>0</hashers>
        <order>random</order>
        <ignoreDelete>false</ignoreDelete>
        <scanProgressIntervalS>0</scanProgressIntervalS>
        <pullerPauseS>0</pullerPauseS>
        <maxConflicts>-1</maxConflicts>
        <disableSparseFiles>false</disableSparseFiles>
        <disableTempIndexes>false</disableTempIndexes>
        <paused>false</paused>
        <weakHashThresholdPct>25</weakHashThresholdPct>
        <markerName>.stfolder</markerName>
        <copyOwnershipFromParent>false</copyOwnershipFromParent>
        <modTimeWindowS>0</modTimeWindowS>
        <maxConcurrentWrites>2</maxConcurrentWrites>
        <disableFsync>false</disableFsync>
        <blockPullOrder>standard</blockPullOrder>
        <copyRangeMethod>standard</copyRangeMethod>
    </folder>
    <device id="3LT2GA5-CQI4XJM-WTZ264P-MLOGMHL-MCRLDNT-MZV4RD3-KA745CL-OGAERQZ" name="syno" compression="metadata" introducer="false" skipIntroductionRemovals="false" introducedBy="">
        <address>dynamic</address>
        <paused>false</paused>
        <autoAcceptFolders>false</autoAcceptFolders>
        <maxSendKbps>0</maxSendKbps>
        <maxRecvKbps>0</maxRecvKbps>
        <maxRequestKiB>0</maxRequestKiB>
    </device>
    <gui enabled="true" tls="false" debugging="false">
        <address>127.0.0.1:8384</address>
        <apikey>k1dnz1Dd0rzTBjjFFh7CXPnrF12C49B1</apikey>
        <theme>default</theme>
    </gui>
    <ldap></ldap>
    <options>
        <listenAddress>tcp://0.0.0.0:8384</listenAddress>
        <listenAddress>dynamic+https://relays.syncthing.net/endpoint</listenAddress>
        <globalAnnounceServer>default</globalAnnounceServer>
        <globalAnnounceEnabled>true</globalAnnounceEnabled>
        <localAnnounceEnabled>true</localAnnounceEnabled>
        <localAnnouncePort>21027</localAnnouncePort>
        <localAnnounceMCAddr>[ff12::8384]:21027</localAnnounceMCAddr>
        <maxSendKbps>0</maxSendKbps>
        <maxRecvKbps>0</maxRecvKbps>
        <reconnectionIntervalS>60</reconnectionIntervalS>
        <relaysEnabled>true</relaysEnabled>
        <relayReconnectIntervalM>10</relayReconnectIntervalM>
        <startBrowser>true</startBrowser>
        <natEnabled>true</natEnabled>
        <natLeaseMinutes>60</natLeaseMinutes>
        <natRenewalMinutes>30</natRenewalMinutes>
        <natTimeoutSeconds>10</natTimeoutSeconds>
        <urAccepted>0</urAccepted>
        <urSeen>0</urSeen>
        <urUniqueID></urUniqueID>
        <urURL>https://data.syncthing.net/newdata</urURL>
        <urPostInsecurely>false</urPostInsecurely>
        <urInitialDelayS>1800</urInitialDelayS>
        <restartOnWakeup>true</restartOnWakeup>
        <autoUpgradeIntervalH>12</autoUpgradeIntervalH>
        <upgradeToPreReleases>false</upgradeToPreReleases>
        <keepTemporariesH>24</keepTemporariesH>
        <cacheIgnoredFiles>false</cacheIgnoredFiles>
        <progressUpdateIntervalS>5</progressUpdateIntervalS>
        <limitBandwidthInLan>false</limitBandwidthInLan>
        <minHomeDiskFree unit="%">1</minHomeDiskFree>
        <releasesURL>https://upgrades.syncthing.net/meta.json</releasesURL>
        <overwriteRemoteDeviceNamesOnConnect>false</overwriteRemoteDeviceNamesOnConnect>
        <tempIndexMinBlocks>10</tempIndexMinBlocks>
        <trafficClass>0</trafficClass>
        <defaultFolderPath>~</defaultFolderPath>
        <setLowPriority>true</setLowPriority>
        <maxFolderConcurrency>0</maxFolderConcurrency>
        <crashReportingURL>https://crash.syncthing.net/newcrash</crashReportingURL>
        <crashReportingEnabled>true</crashReportingEnabled>
        <stunKeepaliveStartS>180</stunKeepaliveStartS>
        <stunKeepaliveMinS>20</stunKeepaliveMinS>
        <stunServer>default</stunServer>
        <databaseTuning>auto</databaseTuning>
        <maxConcurrentIncomingRequestKiB>0</maxConcurrentIncomingRequestKiB>
    </options>
</configuration>

CONFIGURATION ELEMENT

<configuration version="30">
    <folder></folder>
    <device></device>
    <gui></gui>
    <ldap></ldap>
    <options></options>
    <ignoredDevice>5SYI2FS-LW6YAXI-JJDYETS-NDBBPIO-256MWBO-XDPXWVG-24QPUM4-PDW4UQU</ignoredDevice>
    <ignoredFolder>bd7q3-zskm5</ignoredFolder>
</configuration>

This is the root element. It has one attribute:

version
    The config version. Increments whenever a change is made that requires migration from previous formats.

    It contains the elements described in the following sections and these two additional child elements:

ignoredDevice
    Contains the ID of the device that should be ignored. Connection attempts from this device are logged to the console but never displayed in the web GUI.

ignoredFolder
    Contains the ID of the folder that should be ignored. This folder will always be skipped when advertised from a remote device, i.e. this will be logged, but there will be no dialog about it in the web GUI.

FOLDER ELEMENT

<folder id="default" label="Default Folder" path="/Users/jb/Sync/" type="sendreceive" rescanIntervalS="3600" fsWatcherEnabled="true" fsWatcherDelayS="10" ignorePerms="false" autoNormalize="true">
    <filesystemType>basic</filesystemType>
    <device id="3LT2GA5-CQI4XJM-WTZ264P-MLOGMHL-MCRLDNT-MZV4RD3-KA745CL-OGAERQZ"></device>
    <minDiskFree unit="%">1</minDiskFree>
    <versioning></versioning>
    <copiers>0</copiers>
    <pullerMaxPendingKiB>0</pullerMaxPendingKiB>
    <hashers>0</hashers>
    <order>random</order>
    <ignoreDelete>false</ignoreDelete>
    <scanProgressIntervalS>0</scanProgressIntervalS>
    <pullerPauseS>0</pullerPauseS>
    <maxConflicts>-1</maxConflicts>
    <disableSparseFiles>false</disableSparseFiles>
    <disableTempIndexes>false</disableTempIndexes>
    <paused>false</paused>
    <weakHashThresholdPct>25</weakHashThresholdPct>
    <markerName>.stfolder</markerName>
    <copyOwnershipFromParent>false</copyOwnershipFromParent>
    <modTimeWindowS>0</modTimeWindowS>
    <maxConcurrentWrites>2</maxConcurrentWrites>
    <disableFsync>false</disableFsync>
    <blockPullOrder>standard</blockPullOrder>
    <copyRangeMethod>standard</copyRangeMethod>
</folder>

One or more folder elements must be present in the file. Each element describes one folder. The following attributes may be set on the folder element:

id  The folder ID, must be unique. (mandatory)

label
    The label of a folder is a human readable and descriptive local name. May be different on each device, empty, and/or identical to other folder labels. (optional)

path
    The path to the directory where the folder is stored on this device; not sent to other devices. (mandatory)

type
    Controls how the folder is handled by Syncthing. Possible values are:

sendreceive
    The folder is in default mode. Sending local and accepting remote changes. Note that this type was previously called “readwrite” which is deprecated but still accepted in incoming configs.

sendonly
    The folder is in “send only” mode – it will not be modified by Syncthing on this device. Note that this type was previously called “readonly” which is deprecated but still accepted in incoming configs.

receiveonly
    The folder is in “receive only” mode – it will not propagate changes to other devices.

rescanIntervalS
    The rescan interval, in seconds. Can be set to zero to disable when external plugins are used to trigger rescans.

fsWatcherEnabled
    If enabled this detects changes to files in the folder and scans them.

fsWatcherDelayS
    The duration during which changes detected are accumulated, before a scan is scheduled (only takes effect if fsWatcherEnabled is true).

ignorePerms
    True if the folder should ignore permissions.

autoNormalize
    Automatically correct UTF-8 normalization errors found in file names.

    The following child elements may exist:

device
    These must have the id attribute and can have an introducedBy attribute, identifying the device that introduced us to share this folder with the given device. If the original introducer unshares this folder with this device, our device will follow and unshare the folder (subject to skipIntroductionRemovals being false on the introducer device). All mentioned devices are those that will be sharing the folder in question. Each mentioned device must have a separate device element later in the file. It is customary that the local device ID is included in all folders. Syncthing will currently add this automatically if it is not present in the configuration file.

minDiskFree
    The minimum required free space that should be available on the disk this folder resides. The folder will be stopped when the value drops below the threshold. Accepted units are %, kB, MB, GB and TB. Set to zero to disable.

versioning
    Specifies a versioning configuration.

    SEE ALSO: versioning

copiers, pullers, hashers
    The number of copier, puller and hasher routines to use, or zero for the system determined optimum. These are low level performance options for advanced users only; do not change unless requested to or you’ve actually read and understood the code yourself. :)

order
    The order in which needed files should be pulled from the cluster. The possibles values are:

random
    Pull files in random order. This optimizes for balancing resources among the devices in a cluster.

alphabetic
    Pull files ordered by file name alphabetically.

smallestFirst, largestFirst
    Pull files ordered by file size; smallest and largest first respectively.

oldestFirst, newestFirst
    Pull files ordered by modification time; oldest and newest first respectively.

    Note that the scanned files are sent in batches and the sorting is applied only to the already discovered files. This means the sync might start with a 1 GB file even if there is 1 KB file available on the source device until the 1 KB becomes known to the pulling device.

ignoreDelete
    When set to true, this device will pretend not to see instructions to delete files from other devices.

scanProgressIntervalS
    The interval with which scan progress information is sent to the GUI. Zero means the default value (two seconds).

pullerPauseS
    Tweak for rate limiting the puller when it retries pulling files. Don’t change these unless you know what you’re doing.

maxConflicts
    The maximum number of conflict copies to keep around for any given file. The default, -1, means an unlimited number. Setting this to zero disables conflict copies altogether.

disableSparseFiles
    By default, blocks containing all zeroes are not written, causing files to be sparse on filesystems that support the concept. When set to true, sparse files will not be created.

disableTempIndexes
    By default, devices exchange information about blocks available in transfers that are still in progress, which allows other devices to download parts of files that are not yet fully downloaded on your own device, essentially making transfers more torrent like. When set to true, such information is not exchanged for this folder.

paused
    True if this folder is (temporarily) suspended.

weakHashThresholdPct
    Use weak hash if more than the given percentage of the file has changed. Set to -1 to always use weak hash. Default value is 25.

markerName
    Name of a directory or file in the folder root to be used as marker-faq. Default is “.stfolder”.

copyOwnershipFromParent
    On Unix systems, tries to copy file/folder ownership from the parent directory (the directory it’s located in). Requires running Syncthing as privileged user, or granting it additional capabilities (e.g. CAP_CHOWN on Linux).

modTimeWindowS
    Allowed modification timestamp difference when comparing files for equivalence. To be used on systems that have unstable modification timestamps, that might change after being observed after the last write operation. Used in Android only.

maxConcurrentWrites
    Maximum number of concurrent write operations while syncing. Defaults to 2. Increasing this might increase or decrease disk performance, depending on the underlying storage.

    disableFsync

    WARNING: This is a known insecure option - use at your own risk.

    Disables committing file operations to disk before recording them in the database. Disabling fsync can lead to data corruption.

blockPullOrder
    Order in which the blocks of a file are downloaded. This option controls how quickly different parts of the file spread between the connected devices, at the cost of causing strain on the storage.

    Available options:

standard (default):
    The blocks of a file are split into N equal continuous sequences, where N is the number of connected devices. Each device starts downloading it’s own sequence, after which it picks other devices sequences at random. Provides acceptable data distribution and minimal spinning disk strain.

random:
    The blocks of a file are downloaded in a random order. Provides great data distribution, but very taxing on spinning disk drives.

inOrder:
    The blocks of a file are downloaded sequentially, from start to finish. Spinning disk drive friendly, but provides no improvements to data distribution.

copyRangeMethod
    Provides a choice of method for copying data between files. This can be used to optimise copies on network filesystems, improve speed of large copies or clone the data using copy-on-write functionality if the underlying filesystem supports it.

    See folder-copyRangeMethod for details.

DEVICE ELEMENT

<device id="5SYI2FS-LW6YAXI-JJDYETS-NDBBPIO-256MWBO-XDPXWVG-24QPUM4-PDW4UQU" name="syno" compression="metadata" introducer="false" skipIntroductionRemovals="false" introducedBy="2CYF2WQ-AKZO2QZ-JAKWLYD-AGHMQUM-BGXUOIS-GYILW34-HJG3DUK-LRRYQAR">
    <address>dynamic</address>
    <paused>false</paused>
    <autoAcceptFolders>false</autoAcceptFolders>
    <maxSendKbps>0</maxSendKbps>
    <maxRecvKbps>0</maxRecvKbps>
    <maxRequestKiB>0</maxRequestKiB>
</device>
<device id="2CYF2WQ-AKZO2QZ-JAKWLYD-AGHMQUM-BGXUOIS-GYILW34-HJG3DUK-LRRYQAR" name="syno local" compression="metadata" introducer="false" skipIntroductionRemovals="false" introducedBy="">
    <address>tcp://192.0.2.1:22001</address>
    <paused>true</paused>
    <allowedNetwork>192.168.0.0/16</allowedNetwork>
    <autoAcceptFolders>false</autoAcceptFolders>
    <maxSendKbps>100</maxSendKbps>
    <maxRecvKbps>100</maxRecvKbps>
    <maxRequestKiB>65536</maxRequestKiB>
</device>

One or more device elements must be present in the file. Each element describes a device participating in the cluster. It is customary to include a device element for the local device; Syncthing will currently add one if it is not present. The following attributes may be set on the device element:

id  The device ID. This must be written in canonical form, that is without any spaces or dashes. (mandatory)

name
    A friendly name for the device. (optional)

compression
    Whether to use protocol compression when sending messages to this device. The possible values are:

metadata
    Compress metadata packets, such as index information. Metadata is usually very compression friendly so this is a good default.

always
    Compress all packets, including file data. This is recommended if the folders contents are mainly compressible data such as documents or text files.

never
    Disable all compression.

introducer
    Set to true if this device should be trusted as an introducer, i.e. we should copy their list of devices per folder when connecting.

    SEE ALSO: introducer

skipIntroductionRemovals
    Set to true if you wish to follow only introductions and not de-introductions. For example, if this is set, we would not remove a device that we were introduced to even if the original introducer is no longer listing the remote device as known.

introducedBy
    Defines which device has introduced us to this device. Used only for following de-introductions.

certName
    The device certificate common name, if it is not the default “syncthing”.

    From following child elements at least one address child must exist.

address
    Contains an address or host name to use when attempting to connect to this device. Entries other than dynamic must be prefixed with tcp:// (dual-stack), tcp4:// (IPv4 only) or tcp6:// (IPv6 only). Note that IP addresses need not use tcp4/tcp6; these are optional. Accepted formats are:

IPv4 address (tcp://192.0.2.42)
    The default port (22000) is used.

IPv4 address and port (tcp://192.0.2.42:12345)
    The address and port is used as given.

IPv6 address (tcp://[2001:db8::23:42])
    The default port (22000) is used. The address must be enclosed in square brackets.

IPv6 address and port (tcp://[2001:db8::23:42]:12345)
    The address and port is used as given. The address must be enclosed in square brackets.

Host name (tcp6://fileserver)
    The host name will be used on the default port (22000) and connections will be attempted only via IPv6.

Host name and port (tcp://fileserver:12345)
    The host name will be used on the given port and connections will be attempted via both IPv4 and IPv6, depending on name resolution.

dynamic
    The word dynamic (without tcp:// prefix) means to use local and global discovery to find the device.

    You can set multiple addresses and combine it with the dynamic keyword for example:

    <device id="...">
        <address>tcp://192.0.2.1:22001</address>
        <address>tcp://192.0.1.254:22000</address>
        <address>dynamic</address>
    </device>

paused
    True if synchronization with this devices is (temporarily) suspended.

allowedNetwork
    If given, this restricts connections to this device to only this network (see allowed-networks).

maxSendKbps
    Maximum send rate to use for this device. Unit is kibibytes/second, despite the config name looking like kilobits/second.

maxRecvKbps
    Maximum receive rate to use for this device. Unit is kibibytes/second, despite the config name looking like kilobits/second.

maxRequestKiB
    Maximum amount of data to have outstanding in requests towards this device. Unit is kibibytes.

GUI ELEMENT

<gui enabled="true" tls="false" debugging="false">
    <address>127.0.0.1:8384</address>
    <apikey>l7jSbCqPD95JYZ0g8vi4ZLAMg3ulnN1b</apikey>
    <theme>default</theme>
</gui>

There must be exactly one gui element. The GUI configuration is also used by the rest-api and the event-api. The following attributes may be set on the gui element:

enabled
    If not true, the GUI and API will not be started.

tls If set to true, TLS (HTTPS) will be enforced. Non-HTTPS requests will be redirected to HTTPS. When this is set to false, TLS connections are still possible but it is not mandatory.

debugging
    This enables profiling and additional debugging endpoints in the rest-api.

    The following child elements may be present:

address
    Set the listen address. One address element must be present. Allowed address formats are:

IPv4 address and port (127.0.0.1:8384)
    The address and port is used as given.

IPv6 address and port ([::1]:8384)
    The address and port is used as given. The address must be enclosed in square brackets.

Wildcard and port (0.0.0.0:12345, [::]:12345, :12345)
    These are equivalent and will result in Syncthing listening on all interfaces via both IPv4 and IPv6.

UNIX socket location (/var/run/st.sock)
    If the address is an absolute path it is interpreted as the path to a UNIX socket. (Added in v0.14.52.)

unixSocketPermissions
    In the case that a UNIX socket location is used for address, set this to an octal to override the default permissions of the socket.

user
    Set to require authentication.

password
    Contains the bcrypt hash of the real password.

apikey
    If set, this is the API key that enables usage of the REST interface.

insecureAdminAccess
    If true, this allows access to the web GUI from outside (i.e. not localhost) without authorization. A warning will displayed about this setting on startup.

theme
    The name of the theme to use.

authMode
    Authentication mode to use. If not present authentication mode (static) is controlled by presence of user/password fields for backward compatibility.

static
    Authentication using user and password.

ldap
    LDAP authentication. Requires ldap top level config section to be present.

LDAP ELEMENT

<ldap>
    <address>localhost:389</address>
    <bindDN>cn=%s,ou=users,dc=syncthing,dc=net</bindDN>
    <transport>nontls</transport>
    <insecureSkipVerify>false</insecureSkipVerify>
</ldap>

The ldap element contains LDAP configuration options.

address
    LDAP server address (server:port).

bindDN
    BindDN for user authentication. Special %s variable should be used to pass username to LDAP.

    transport

nontls
    Non secure connection.

tls TLS secured connection.

starttls
    StartTLS connection mode.

insecureSkipVerify
    Skip verification (true or false).

OPTIONS ELEMENT

<options>
    <listenAddress>tcp://0.0.0.0:8384</listenAddress>
    <listenAddress>dynamic+https://relays.syncthing.net/endpoint</listenAddress>
    <globalAnnounceServer>default</globalAnnounceServer>
    <globalAnnounceEnabled>true</globalAnnounceEnabled>
    <localAnnounceEnabled>true</localAnnounceEnabled>
    <localAnnouncePort>21027</localAnnouncePort>
    <localAnnounceMCAddr>[ff12::8384]:21027</localAnnounceMCAddr>
    <maxSendKbps>0</maxSendKbps>
    <maxRecvKbps>0</maxRecvKbps>
    <reconnectionIntervalS>60</reconnectionIntervalS>
    <relaysEnabled>true</relaysEnabled>
    <relayReconnectIntervalM>10</relayReconnectIntervalM>
    <startBrowser>true</startBrowser>
    <natEnabled>true</natEnabled>
    <natLeaseMinutes>60</natLeaseMinutes>
    <natRenewalMinutes>30</natRenewalMinutes>
    <natTimeoutSeconds>10</natTimeoutSeconds>
    <urAccepted>0</urAccepted>
    <urSeen>0</urSeen>
    <urUniqueID></urUniqueID>
    <urURL>https://data.syncthing.net/newdata</urURL>
    <urPostInsecurely>false</urPostInsecurely>
    <urInitialDelayS>1800</urInitialDelayS>
    <restartOnWakeup>true</restartOnWakeup>
    <autoUpgradeIntervalH>12</autoUpgradeIntervalH>
    <upgradeToPreReleases>false</upgradeToPreReleases>
    <keepTemporariesH>24</keepTemporariesH>
    <cacheIgnoredFiles>false</cacheIgnoredFiles>
    <progressUpdateIntervalS>5</progressUpdateIntervalS>
    <limitBandwidthInLan>false</limitBandwidthInLan>
    <minHomeDiskFree unit="%">1</minHomeDiskFree>
    <releasesURL>https://upgrades.syncthing.net/meta.json</releasesURL>
    <overwriteRemoteDeviceNamesOnConnect>false</overwriteRemoteDeviceNamesOnConnect>
    <tempIndexMinBlocks>10</tempIndexMinBlocks>
    <trafficClass>0</trafficClass>
    <defaultFolderPath>~</defaultFolderPath>
    <setLowPriority>true</setLowPriority>
    <maxFolderConcurrency>0</maxFolderConcurrency>
    <crashReportingURL>https://crash.syncthing.net/newcrash</crashReportingURL>
    <crashReportingEnabled>true</crashReportingEnabled>
    <stunKeepaliveStartS>180</stunKeepaliveStartS>
    <stunKeepaliveMinS>20</stunKeepaliveMinS>
    <stunServer>default</stunServer>
    <databaseTuning>auto</databaseTuning>
    <maxConcurrentIncomingRequestKiB>0</maxConcurrentIncomingRequestKiB>
</options>

The options element contains all other global configuration options.

listenAddress
    The listen address for incoming sync connections. See Listen Addresses for allowed syntax.

globalAnnounceServer
    A URI to a global announce (discovery) server, or the word default to include the default servers. Any number of globalAnnounceServer elements may be present. The syntax for non-default entries is that of a HTTP or HTTPS URL. A number of options may be added as query options to the URL: insecure to prevent certificate validation (required for HTTP URLs) and id=<device ID> to perform certificate pinning. The device ID to use is printed by the discovery server on startup.

globalAnnounceEnabled
    Whether to announce this device to the global announce (discovery) server, and also use it to look up other devices.

localAnnounceEnabled
    Whether to send announcements to the local LAN, also use such announcements to find other devices.

localAnnouncePort
    The port on which to listen and send IPv4 broadcast announcements to.

localAnnounceMCAddr
    The group address and port to join and send IPv6 multicast announcements on.

maxSendKbps
    Outgoing data rate limit, in kibibytes per second.

maxRecvKbps
    Incoming data rate limits, in kibibytes per second.

reconnectionIntervalS
    The number of seconds to wait between each attempt to connect to currently unconnected devices.

relaysEnabled
    When true, relays will be connected to and potentially used for device to device connections.

relayReconnectIntervalM
    Sets the interval, in minutes, between relay reconnect attempts.

startBrowser
    Whether to attempt to start a browser to show the GUI when Syncthing starts.

natEnabled
    Whether to attempt to perform a UPnP and NAT-PMP port mapping for incoming sync connections.

natLeaseMinutes
    Request a lease for this many minutes; zero to request a permanent lease.

natRenewalMinutes
    Attempt to renew the lease after this many minutes.

natTimeoutSeconds
    When scanning for UPnP devices, wait this long for responses.

urAccepted
    Whether the user has accepted to submit anonymous usage data. The default, 0, mean the user has not made a choice, and Syncthing will ask at some point in the future. -1 means no, a number above zero means that that version of usage reporting has been accepted.

urSeen
    The highest usage reporting version that has already been shown in the web GUI.

urUniqueID
    The unique ID sent together with the usage report. Generated when usage reporting is enabled.

urURL
    The URL to post usage report data to, when enabled.

urPostInsecurely
    When true, the UR URL can be http instead of https, or have a self-signed certificate. The default is false.

urInitialDelayS
    The time to wait from startup to the first usage report being sent. Allows the system to stabilize before reporting statistics.

restartOnWakeup
    Whether to perform a restart of Syncthing when it is detected that we are waking from sleep mode (i.e. a folded up laptop).

autoUpgradeIntervalH
    Check for a newer version after this many hours. Set to zero to disable automatic upgrades.

upgradeToPreReleases
    If true, automatic upgrades include release candidates (see releases).

keepTemporariesH
    Keep temporary failed transfers for this many hours. While the temporaries are kept, the data they contain need not be transferred again.

cacheIgnoredFiles
    Whether to cache the results of ignore pattern evaluation. Performance at the price of memory. Defaults to false as the cost for evaluating ignores is usually not significant.

progressUpdateIntervalS
    How often in seconds the progress of ongoing downloads is made available to the GUI.

limitBandwidthInLan
    Whether to apply bandwidth limits to devices in the same broadcast domain as the local device.

minHomeDiskFree
    The minimum required free space that should be available on the partition holding the configuration and index. Accepted units are %, kB, MB, GB and TB.

releasesURL
    The URL from which release information is loaded, for automatic upgrades.

alwaysLocalNet
    Network that should be considered as local given in CIDR notation.

overwriteRemoteDeviceNamesOnConnect
    If set, device names will always be overwritten with the name given by remote on each connection. By default, the name that the remote device announces will only be adopted when a name has not already been set.

tempIndexMinBlocks
    When exchanging index information for incomplete transfers, only take into account files that have at least this many blocks.

unackedNotificationID
    ID of a notification to be displayed in the web GUI. Will be removed once the user acknowledged it (e.g. an transition notice on an upgrade).

trafficClass
    Specify a type of service (TOS)/traffic class of outgoing packets.

stunServer
    Server to be used for STUN, given as ip:port. The keyword default gets expanded to stun.callwithus.com:3478, stun.counterpath.com:3478, stun.counterpath.net:3478, stun.ekiga.net:3478, stun.ideasip.com:3478, stun.internetcalls.com:3478, stun.schlund.de:3478, stun.sipgate.net:10000, stun.sipgate.net:3478, stun.voip.aebc.com:3478, stun.voiparound.com:3478, stun.voipbuster.com:3478, stun.voipstunt.com:3478 and stun.xten.com:3478 (this is the default).

stunKeepaliveSeconds
    Interval in seconds between contacting a STUN server to maintain NAT mapping. Default is 24 and you can set it to 0 to disable contacting STUN servers.

defaultFolderPath
    The UI will propose to create new folders at this path. This can be disabled by setting this to an empty string.

setLowPriority
    Syncthing will attempt to lower its process priority at startup. Specifically: on Linux, set itself to a separate process group, set the niceness level of that process group to nine and the I/O priority to best effort level five; on other Unixes, set the process niceness level to nine; on Windows, set the process priority class to below normal. To disable this behavior, for example to control process priority yourself as part of launching Syncthing, set this option to false.

  Listen Addresses

The following address types are accepted in sync protocol listen addresses. If you want Syncthing to listen on multiple addresses, you can have multiple <listenAddress> tags. The same is achieved in the GUI by entering several addresses separated by comma.

Default listen addresses (default)
    This is equivalent to tcp://0.0.0.0:22000, quic://0.0.0.0:22000 and dynamic+https://relays.syncthing.net/endpoint.

TCP wildcard and port (tcp://0.0.0.0:22000, tcp://:22000)
    These are equivalent and will result in Syncthing listening on all interfaces, IPv4 and IPv6, on the specified port.

TCP IPv4 wildcard and port (tcp4://0.0.0.0:22000, tcp4://:22000)
    These are equivalent and will result in Syncthing listening on all interfaces via IPv4 only.

TCP IPv4 address and port (tcp4://192.0.2.1:22000)
    This results in Syncthing listening on the specified address and port, IPv4 only.

TCP IPv6 wildcard and port (tcp6://[::]:22000, tcp6://:22000)
    These are equivalent and will result in Syncthing listening on all interfaces via IPv6 only.

TCP IPv6 address and port (tcp6://[2001:db8::42]:22000)
    This results in Syncthing listening on the specified address and port, IPv6 only.

QUIC address and port (e.g. quic://0.0.0.0:22000)
    Syntax is the same as for TCP, also quic4 and quic6 can be used.

Static relay address (relay://192.0.2.42:22067?id=abcd123...)
    Syncthing will connect to and listen for incoming connections via the specified relay address.

  Todo

Document available URL parameters.

Dynamic relay pool (dynamic+https://192.0.2.42/relays)
    Syncthing will fetch the specified HTTPS URL, parse it for a JSON payload describing relays, select a relay from the available ones and listen via that as if specified as a static relay above.

  Todo

Document available URL parameters.

SYNCING CONFIGURATION FILES

Syncing configuration files between devices (such that multiple devices are using the same configuration files) can cause issues. This is easy to do accidentally if you sync your home folder between devices. A common symptom of syncing configuration files is two devices ending up with the same Device ID.

If you want to use Syncthing to backup your configuration files, it is recommended that the files you are backing up are in a folder-sendonly to prevent other devices from overwriting the per device configuration. The folder on the remote device(s) should not be used as configuration for the remote devices.

If you’d like to sync your home folder in non-send only mode, you may add the folder that stores the configuration files to the ignore list. If you’d also like to backup your configuration files, add another folder in send only mode for just the configuration folder.

AUTHOR
The Syncthing Authors

COPYRIGHT
2014-2019, The Syncthing Authors