transmission-api

name	transmission-api
description	Transmission RPC reference covering JSON-RPC 2.0 transport, session token handling, torrent methods, session methods, and protocol versioning.

[!IMPORTANT] Transmisson 4.1.0 (rpc_version_semver 6.0.0) added support for the JSON-RPC 2.0 protocol and converted all RPC strings to snake_case.

The old bespoke RPC protocol, and the old mix of kebab-case and camelCase strings, are still supported in Transmission 4 but are deprecated and will be removed in the future. People using the old protocol should update their code!

For documentation of the old RPC protocol and strings, please consult documentation from previous versions. https://github.com/transmission/transmission/blob/4.0.6/docs/rpc-spec.md

Transmission's RPC specification

This document describes a protocol for interacting with Transmission sessions remotely.

1.1 Terminology

The JSON terminology in RFC 8259 is used. RPC requests and responses are formatted in JSON.

1.2 Tools

If transmission-remote is called with a --debug argument, its RPC traffic to the Transmission server will be dumped to the terminal. This can be useful when you want to compare requests in your application to another for reference.

If transmission-qt is run with an environment variable TR_RPC_VERBOSE set, it too will dump the RPC requests and responses to the terminal for inspection.

Lastly, using the browser's developer tools in the Transmission web client is always an option.

1.3 Libraries of ready-made wrappers

Some people outside of the Transmission project have written libraries that wrap this RPC API. These aren't supported by the Transmission project, but are listed here in the hope that they may be useful:

Language	Link
C# .NET10	https://www.nuget.org/packages/Transmission.API.RPC.NET/
C#	https://www.nuget.org/packages/Transmission.API.RPC
Go	https://github.com/hekmon/transmissionrpc
Python	https://github.com/Trim21/transmission-rpc
Rust	https://crates.io/crates/transmission-rpc

2 Message format

Transmission follows the JSON-RPC 2.0 specification and supports the entirety of it, except that parameters by-position is not supported, meaning the request parameters must be an Object.

Response parameters are returned in the result Object.

Example request

{
   "jsonrpc": "2.0",
   "params": {
     "fields": [ "version" ]
   },
   "method": "session_get",
   "id": 912313
}

Example response

{
   "jsonrpc": "2.0",
   "result": {
      "version": "4.1.0-dev (ae226418eb)"
   },
   "id": 912313
}

2.1 Error data

JSON-RPC 2.0 allows for additional information about an error be included in the data key of the Error object in an implementation-defined format.

In Transmission, this key is an Object that includes:

1. An optional error_string string that provides additional information that is not included in the message key of the Error object.
2. An optional result Object that contains additional keys defined by the method.

{
   "jsonrpc": "2.0",
   "error": {
      "code": 7,
      "message": "HTTP error from backend service",
      "data": {
         "error_string": "Couldn't test port: No Response (0)",
         "result": {
            "ip_protocol": "ipv6"
         }
      }
   },
   "id": 912313
}

2.2 Transport mechanism

HTTP POSTing a JSON-encoded request is the preferred way of communicating with a Transmission RPC server. The current Transmission implementation has the default URL as http://host:9091/transmission/rpc. Clients may use this as a default, but should allow the URL to be reconfigured, since the port and path may be changed to allow mapping and/or multiple daemons to run on a single server.

The RPC server will normally return HTTP 200 regardless of whether the request succeeded. For JSON-RPC 2.0 notifications, HTTP 204 will be returned.

2.2.1 CSRF protection

Most Transmission RPC servers require a X-Transmission-Session-Id header to be sent with requests, to prevent CSRF attacks.

When your request has the wrong id -- such as when you send your first request, or when the server expires the CSRF token -- the Transmission RPC server will return an HTTP 409 error with the right X-Transmission-Session-Id in its own headers.

So, the correct way to handle a 409 response is to update your X-Transmission-Session-Id and to resend the previous request.

2.2.2 DNS rebinding protection

Additional check is being made on each RPC request to make sure that the client sending the request does so using one of the allowed hostnames by which RPC server is meant to be available.

If host whitelisting is enabled (which is true by default), Transmission inspects the Host: HTTP header value (with port stripped, if any) and matches it to one of the whitelisted names. Regardless of host whitelist content, localhost and localhost. domain names as well as all the IP addresses are always implicitly allowed.

For more information on configuration, see Editing Configuration Files documentation for rpc_host_whitelist_enabled and rpc_host_whitelist keys.

2.2.3 Authentication

Enabling authentication is an optional security feature that can be enabled on Transmission RPC servers. Authentication occurs by method of HTTP Basic Access Authentication.

If authentication is enabled, Transmission inspects the Authorization: HTTP header value to validate the credentials of the request. The value of this HTTP header is expected to be Basic <b64 credentials>, where is equal to a base64 encoded string of the username and password (respectively), separated by a colon.

3 Torrent requests

3.1 Torrent action requests

Method name	libtransmission function	Description
torrent_start	tr_torrentStart	start torrent
torrent_start_now	tr_torrentStartNow	start torrent disregarding queue position
torrent_stop	tr_torrentStop	stop torrent
torrent_verify	tr_torrentVerify	verify torrent
torrent_reannounce	tr_torrentManualUpdate	re-announce to trackers now

Request parameters: ids, which specifies which torrents to use. All torrents are used if the ids parameter is omitted.

ids should be one of the following:

1. an integer referring to a torrent id
2. a list of torrent id numbers, SHA1 hash strings, or both
3. a string, recently_active, for recently-active torrents

Note that integer torrent ids are not stable across Transmission daemon restarts. Use torrent hashes if you need stable ids.

Response parameters: none

3.2 Torrent mutator: torrent_set

Method name: torrent_set

Request parameters:

Key	Value Type	Value Description
bandwidth_priority	number	this torrent's bandwidth tr_priority_t
download_limit	number	maximum download speed (kB/s)
download_limited	boolean	true if download_limit is honored
files_unwanted	array	indices of file(s) to not download
files_wanted	array	indices of file(s) to download
group	string	The name of this torrent's bandwidth group
honors_session_limits	boolean	true if session upload limits are honored
ids	array	torrent list, as described in 3.1
labels	array	array of string labels
location	string	new location of the torrent's content
peer_limit	number	maximum number of peers
priority_high	array	indices of high-priority file(s)
priority_low	array	indices of low-priority file(s)
priority_normal	array	indices of normal-priority file(s)

Just as an empty ids value is shorthand for "all ids", using an empty array for files_wanted, files_unwanted, priority_high, priority_low, or priority_normal is shorthand for saying "all files".

Response parameters: none

3.3 Torrent accessor: torrent_get

Method name: torrent_get.

Request parameters:

1. An optional ids array as described in 3.1.
2. A required fields array of keys. (see list below)
3. An optional format string specifying how to format the torrents response field. Allowed values are objects (default) and table. (see "Response parameters" below)

Response parameters:

1. A torrents array.

   If the format request was objects (default), torrents will be an array of objects, each of which contains the key/value pairs matching the request's fields arg. This was the only format before Transmission 3 and has some obvious programmer conveniences, such as parsing directly into Javascript objects.

   If the format was table, then torrents will be an array of arrays. The first row holds the keys and each remaining row holds a torrent's values for those keys. This format is more efficient in terms of JSON generation and JSON parsing.

2. If the request's ids field was recently_active, a removed array of torrent-id numbers of recently-removed torrents.

Note: For more information on what these fields mean, see the comments in libtransmission/transmission.h. The 'source' column here corresponds to the data structure there.

Key	Value Type	transmission.h source
activity_date	number	tr_stat
added_date	number	tr_stat
availability	array (see below)	tr_torrentAvailability()
bandwidth_priority	number	tr_priority_t
bytes_completed	array (see below)	n/a
comment	string	tr_torrent_view
corrupt_ever	number	tr_stat
creator	string	tr_torrent_view
date_created	number	tr_torrent_view
desired_available	number	tr_stat
done_date	number	tr_stat
download_dir	string	tr_torrent
downloaded_ever	integer	tr_stat
download_limit	integer	tr_torrent
download_limited	boolean	tr_torrent
edit_date

availability: An array of piece_count numbers representing the number of connected peers that have each piece, or -1 if we already have the piece ourselves.

bytes_completed: An array of tr_info.filecount numbers. Each is the completed bytes for the corresponding file.

files: array of objects, each containing:

Key	Value Type	transmission.h source
bytes_completed	number	tr_file_view
length	number	tr_file_view
name	string	tr_file_view
begin_piece	number	tr_file_view
end_piece	number	tr_file_view

Files are returned in the order they are laid out in the torrent. References to "file indices" throughout this specification should be interpreted as the position of the file within this ordering, with the first file bearing index 0.

file_stats: a file's non-constant properties. An array of tr_info.filecount objects, in the same order as files, each containing:

Key	Value Type	transmission.h source
bytes_completed	number	tr_file_view
wanted	boolean	tr_file_view
priority	number	tr_file_view

peers: an array of objects, each containing:

Key	Value Type	transmission.h source
address	string	tr_peer_stat
bytes_to_client	number	tr_peer_stat
bytes_to_peer	number	tr_peer_stat
client_is_choked	boolean	tr_peer_stat
client_is_interested	boolean	tr_peer_stat
client_name	string	tr_peer_stat
flag_str	string	tr_peer_stat
is_downloading_from	boolean	tr_peer_stat
is_encrypted	boolean	tr_peer_stat
is_incoming	boolean	tr_peer_stat
is_uploading_to	boolean	tr_peer_stat
is_utp	boolean	tr_peer_stat
peer_id	string	tr_peer_stat
peer_is_choked	boolean	tr_peer_stat
peer_is_interested	boolean	tr_peer_stat
port

peers_from: an object containing:

Key	Value Type	transmission.h source
from_cache	number	tr_stat
from_dht	number	tr_stat
from_incoming	number	tr_stat
from_lpd	number	tr_stat
from_ltep	number	tr_stat
from_pex	number	tr_stat
from_tracker	number	tr_stat

pieces: A bitfield holding piece_count flags which are set to 'true' if we have the piece matching that position. JSON doesn't allow raw binary data, so this is a base64-encoded string. (Source: tr_torrent)

priorities: An array of tr_torrentFileCount() numbers. Each is the tr_priority_t mode for the corresponding file.

status: A number between 0 and 6, where:

Value	Meaning
0	Torrent is stopped
1	Torrent is queued to verify local data
2	Torrent is verifying local data
3	Torrent is queued to download
4	Torrent is downloading
5	Torrent is queued to seed
6	Torrent is seeding

trackers: array of objects, each containing:

Key	Value Type	transmission.h source
announce	string	tr_tracker_view
id	integer	tr_tracker_view
scrape	string	tr_tracker_view
sitename	string	tr_tracker_view
tier	number	tr_tracker_view

tracker_stats: array of objects, each containing:

Key	Value Type	transmission.h source
announce	string	tr_tracker_view
announce_state	number	tr_tracker_view
download_count	number	tr_tracker_view
downloader_count	number	tr_tracker_view
has_announced	boolean	tr_tracker_view
has_scraped	boolean	tr_tracker_view
host	string	tr_tracker_view
id	integer	tr_tracker_view
is_backup	boolean	tr_tracker_view
last_announce_peer_count	number	tr_tracker_view
last_announce_result	string	tr_tracker_view
last_announce_start_time	number	tr_tracker_view
last_announce_succeeded	boolean	tr_tracker_view
last_announce_time	number	tr_tracker_view
last_announce_timed_out	boolean	tr_tracker_view

webseeds_ex: array of objects, each containing:

Key	Value Type	transmission.h source
url	string	tr_webseed_view
is_downloading	boolean	tr_webseed_view
download_bytes_per_second	number	tr_webseed_view

wanted: An array of tr_torrentFileCount() booleans, true if the corresponding file is to be downloaded. (Source: tr_file_view)

Note: For backwards compatibility, in the old bespoke API, wanted is serialized as an array of 0 or 1 that should be treated as booleans.

Example:

Say we want to get the name and total size of torrents #7 and #10.

Request:

{
   "jsonrpc": "2.0",
   "params": {
       "fields": [ "id", "name", "total_size" ],
       "ids": [ 7, 10 ]
   },
   "method": "torrent_get",
   "id": 39693
}

Response:

{
   "jsonrpc": "2.0",
   "result": {
      "torrents": [
         {
             "id": 10,
             "name": "Fedora x86_64 DVD",
             "total_size": 34983493932
         },
         {
             "id": 7,
             "name": "Ubuntu x86_64 DVD",
             "total_size": 9923890123
         }
      ]
   },
   "id": 39693
}

3.4 Adding a torrent

Method name: torrent_add

Request parameters:

Key	Value Type	Description
cookies	string	pointer to a string of one or more cookies.
download_dir	string	path to download the torrent to
filename	string	filename or URL of the .torrent file
labels	array	array of string labels
metainfo	string	base64-encoded .torrent content
paused	boolean	if true, don't start the torrent
peer_limit	number	maximum number of peers
bandwidth_priority	number	torrent's bandwidth tr_priority_t
files_wanted	array	indices of file(s) to download
files_unwanted	array	indices of file(s) to not download
priority_high	array	indices of high-priority file(s)
priority_low	array	indices of low-priority file(s)
priority_normal	array	indices of normal-priority file(s)
sequential_download	boolean	download torrent pieces sequentially

Either filename or metainfo must be included. All other parameters are optional.

The format of the cookies should be NAME=CONTENTS, where NAME is the cookie name and CONTENTS is what the cookie should contain. Set multiple cookies like this: name1=content1; name2=content2; etc. See libcurl documentation for more information.

Response parameters:

• On success, a torrent_added object in the form of one of 3.3's torrent objects with the fields for id, name, and hash_string.

• When attempting to add a duplicate torrent, a torrent_duplicate object in the same form is returned, but the response's result value is still success.

3.5 Removing a torrent

Method name: torrent_remove

Key	Value Type	Description
ids	array	torrent list, as described in 3.1
delete_local_data	boolean	delete local data. (default: false)

Response parameters: none

3.6 Moving a torrent

Method name: torrent_set_location

Request parameters:

Key	Value Type	Description
ids	array	torrent list, as described in 3.1
location	string	the new torrent location
move	boolean	if true, move from previous location. otherwise, search location for files (default: false)

Response parameters: none

3.7 Renaming a torrent's path

Method name: torrent_rename_path

For more information on the use of this function, see the transmission.h documentation of tr_torrentRenamePath(). In particular, note that if this call succeeds you'll want to update the torrent's files and name field with torrent_get.

Request parameters:

Key	Value Type	Description
ids	array	the torrent list, as described in 3.1 (must only be 1 torrent)
path	string	the path to the file or folder that will be renamed
name	string	the file or folder's new name

Response parameters: path, name, and id, holding the torrent ID integer

4 Session requests

4.1 Session parameters

Key	Value Type	Description
alt_speed_down	number	max global download speed (kB/s)
alt_speed_enabled	boolean	true means use the alt speeds
alt_speed_time_begin	number	when to turn on alt speeds (units: minutes after midnight)
alt_speed_time_day	number	what day(s) to turn on alt speeds (look at tr_sched_day)
alt_speed_time_enabled	boolean	true means the scheduled on/off times are used
alt_speed_time_end	number	when to turn off alt speeds (units: same)
alt_speed_up	number	max global upload speed (kB/s)
anti_brute_force_enabled	boolean	true means to enable a basic brute force protection for RPC server
blocklist_enabled	boolean	true means enabled
blocklist_size	number	number of rules in the blocklist
blocklist_url	string	location of the blocklist to use for blocklist_update
cache_size_mib	number	DEPRECATED This property will be removed in Transmission 5.0.0. Clients should stop using this property now.
config_dir	string

units: an object containing:

Key	Value Type	transmission.h source
speed_units	array	5 strings: B/s, kB/s, MB/s, GB/s, TB/s
speed_bytes	number	number of bytes in a KB (1000 for kB; 1024 for KiB)
size_units	array	5 strings: B, kB, MB, GB, TB
size_bytes	number	number of bytes in a KB (1000 for kB; 1024 for KiB)
memory_units	array	5 strings: B, KiB, MiB, GiB, TiB
memory_bytes	number	number of bytes in a KB (1000 for kB; 1024 for KiB)

4.1.1 Mutators

Method name: session_set

Request parameters: the mutable properties from 4.1's parameters, i.e. all of them except:

• blocklist_size
• config_dir
• rpc_version_minimum,
• rpc_version_semver
• rpc_version
• session_id
• tcp_enabled
• units
• version

Response parameters: none

4.1.2 Accessors

Method name: session_get

Request parameters: an optional fields array of keys (see 4.1)

Response parameters: key/value pairs matching the request's fields parameter if present, or all supported fields (see 4.1) otherwise.

4.2 Session statistics

Method name: session_stats

Request parameters: none

Response parameters:

Key	Value Type	Description
active_torrent_count	number
download_speed	number
paused_torrent_count	number
torrent_count	number
upload_speed	number
cumulative_stats	stats object (see below)
current_stats	stats object (see below)

A stats object contains:

Key	Value Type	transmission.h source
uploaded_bytes	number	tr_session_stats
downloaded_bytes	number	tr_session_stats
files_added	number	tr_session_stats
seconds_active	number	tr_session_stats
session_count	number	tr_session_stats

4.3 Blocklist

Method name: blocklist_update

Request parameters: none

Response parameters: a number blocklist_size

4.4 Port checking

This method tests to see if your incoming peer port is accessible from the outside world.

Method name: port_test

Request parameters: an optional parameter ip_protocol. ip_protocol is a string specifying the IP protocol version to be used for the port test. Set to ipv4 to check IPv4, or set to ipv6 to check IPv6. For backwards compatibility, it is allowed to omit this parameter to get the behaviour before Transmission 4.1.0, which is to check whichever IP protocol the OS happened to use to connect to our port test service, frankly not very useful.

Response parameters:

Key	Value Type	Description
port_is_open	boolean	true if port is open, false if port is closed
ip_protocol	string	ipv4 if the test was carried out on IPv4, ipv6 if the test was carried out on IPv6, unset if it cannot be determined

4.5 Session shutdown

This method tells the Transmission session to shut down.

Method name: session_close

Request parameters: none

Response parameters: none

4.6 Queue movement requests

Method name	transmission.h source
queue_move_top	tr_torrentQueueMoveTop()
queue_move_up	tr_torrentQueueMoveUp()
queue_move_down	tr_torrentQueueMoveDown()
queue_move_bottom	tr_torrentQueueMoveBottom()

Request parameters:

Key	Value Type	Description
ids	array	torrent list, as described in 3.1.

Response parameters: none

4.7 Free space

This method tests how much free space is available in a client-specified folder.

Method name: free_space

Request parameters:

Key	Value type	Description
path	string	the directory to query

Response parameters:

Key	Value type	Description
path	string	same as the Request parameter
size_bytes	number	the size, in bytes, of the free space in that directory
total_size	number	the total capacity, in bytes, of that directory

4.8 Bandwidth groups

4.8.1 Bandwidth group mutator: group_set

Method name: group_set

Request parameters:

Key	Value type	Description
honors_session_limits	boolean	true if session upload limits are honored
name	string	Bandwidth group name
speed_limit_down	integer	max global download speed (kB/s)
speed_limit_down_enabled	boolean	true means enabled
speed_limit_up	integer	max global upload speed (kB/s)
speed_limit_up_enabled	boolean	true means enabled

Response parameters: none

4.8.2 Bandwidth group accessor: group_get

Method name: group_get

Request parameters: An optional parameter name. name is either a string naming the bandwidth group, or a list of such strings. If name is omitted, all bandwidth groups are used.

Response parameters:

Key	Value type	Description
group	array	A list of bandwidth group description objects

A bandwidth group description object has:

Key	Value type	Description
honors_session_limits	boolean	true if session upload limits are honored
name	string	Bandwidth group name
speed_limit_down	integer	max global download speed (kB/s)
speed_limit_down_enabled	boolean	true means enabled
speed_limit_up	integer	max global upload speed (kB/s)
speed_limit_up_enabled	boolean	true means enabled

5 Protocol versions

This section lists the changes that have been made to the RPC protocol.

There are two ways to check for API compatibility. Since most developers know semver, session_get's rpc_version_semver is the recommended way. That value is a semver-compatible string of the RPC protocol version number.

DEPRECATED Since Transmission predates the semver 1.0 spec, the previous scheme was for the RPC version to be a whole number and to increment it whenever a change was made. That is session_get's rpc_version. rpc_version_minimum lists the oldest version that is compatible with the current version; i.e. an app coded to use rpc_version_minimum would still work on a Transmission release running rpc_version.

Starting from rpc-version-semver 6.0.0, Transmission returns the RPC version in an HTTP header X-Transmission-Rpc-Version: {rpc_version_semver} in the CSRF HTTP 409 response. This is so that clients supporting both JSON-RPC and the old bespoke API can determine which scheme to use without making any extra requests. Example: X-Transmission-Rpc-Version: 6.0.0

Breaking changes are denoted with a :bomb: emoji.

Transmission 1.30 (rpc-version-semver 1.0.0, rpc-version: 1)

Initial revision.

Transmission 1.40 (rpc-version-semver 1.1.0, rpc-version: 2)

Method	Description
torrent-get	new port to peers

Transmission 1.41 (rpc-version-semver 1.2.0, rpc-version: 3)

Method	Description
session-get	new arg version
torrent-get	new arg downloaders
torrent-remove	new method

Transmission 1.50 (rpc-version-semver 1.3.0, rpc-version: 4)

Method	Description
session-get	new arg rpc-version-minimum
session-get	new arg rpc-version
session-stats	added cumulative-stats
session-stats	added current-stats
torrent-get	new arg downloadDir

Transmission 1.60 (rpc-version-semver 2.0.0, rpc-version: 5)

Method	Description
session-get	:bomb: renamed peer-limit to peer-limit-global
session-get	:bomb: renamed pex-allowed to pex-enabled
session-get	:bomb: renamed port to peer-port
torrent-get	:bomb: removed arg downloadLimitMode
torrent-get	:bomb: removed arg uploadLimitMode
torrent-set	:bomb: renamed speed-limit-down-enabled to downloadLimited
torrent-set	:bomb: renamed speed-limit-down to downloadLimit
torrent-set	:bomb: renamed speed-limit-up-enabled to uploadLimited
torrent-set	:bomb: renamed speed-limit-up to uploadLimit
blocklist-update	new method
port-test	new method
session-get	new arg alt-speed-begin
session-get	new arg alt-speed-down
session-get	new arg alt-speed-enabled

Transmission 1.70 (rpc-version-semver 2.1.0, rpc-version: 6)

Method	Description
method torrent-set-location	new method

Transmission 1.80 (rpc-version-semver 3.0.0, rpc-version: 7)

Method	Description
torrent-get	:bomb: removed arg announceResponse (use trackerStats instead)
torrent-get	:bomb: removed arg announceURL (use trackerStats instead)
torrent-get	:bomb: removed arg downloaders (use trackerStats instead)
torrent-get	:bomb: removed arg lastAnnounceTime (use trackerStats instead)
torrent-get	:bomb: removed arg lastScrapeTime (use trackerStats instead)
torrent-get	:bomb: removed arg leechers (use trackerStats instead)
torrent-get	:bomb: removed arg nextAnnounceTime (use trackerStats instead)
torrent-get	:bomb: removed arg nextScrapeTime (use trackerStats instead)
torrent-get	:bomb: removed arg scrapeResponse (use trackerStats instead)
torrent-get	:bomb: removed arg scrapeURL (use trackerStats instead)
torrent-get	:bomb: removed arg seeders (use trackerStats instead)
torrent-get	:bomb: removed arg

Transmission 1.90 (rpc-version-semver 3.1.0, rpc-version: 8)

Method	Description
session-set	new arg rename-partial-files
session-get	new arg rename-partial-files
session-get	new arg config-dir
torrent-add	new arg bandwidthPriority
torrent-get	new trackerStats arg lastAnnounceTimedOut

Transmission 1.92 (rpc-version-semver 3.2.0, rpc-version: 8)

Note: rpc-version was not bumped in this release due to an oversight.

Method	Description
torrent-get	new trackerStats arg lastScrapeTimedOut

Transmission 2.00 (rpc-version-semver 3.3.0, rpc-version: 9)

Method	Description
session-set	new arg start-added-torrents
session-set	new arg trash-original-torrent-files
session-get	new arg start-added-torrents
session-get	new arg trash-original-torrent-files
torrent-get	new arg isFinished

Transmission 2.10 (rpc-version-semver 3.4.0, rpc-version: 10)

Method	Description
session-get	new arg cache-size-mb
session-get	new arg units
session-set	new arg idle-seeding-limit-enabled
session-set	new arg idle-seeding-limit
torrent-set	new arg seedIdleLimit
torrent-set	new arg seedIdleMode
torrent-set	new arg trackerAdd
torrent-set	new arg trackerRemove
torrent-set	new arg trackerReplace

Transmission 2.12 (rpc-version-semver 3.5.0, rpc-version: 11)

Method	Description
session-get	new arg blocklist-url
session-set	new arg blocklist-url

Transmission 2.20 (rpc-version-semver 3.6.0, rpc-version: 12)

Method	Description
session-get	new arg download-dir-free-space
session-close	new method

Transmission 2.30 (rpc-version-semver 4.0.0, rpc-version: 13)

Method	Description
torrent-get	:bomb: removed arg peersKnown
torrent-get	new arg isUTP to the peers list
torrent-add	new arg cookies

Transmission 2.40 (rpc-version-semver 5.0.0, rpc-version: 14)

Method	Description
torrent-get	:bomb: values of status field changed
queue-move-bottom	new method
queue-move-down	new method
queue-move-top	new method
session-set	new arg download-queue-enabled
session-set	new arg download-queue-size
session-set	new arg queue-stalled-enabled
session-set	new arg queue-stalled-minutes
session-set	new arg seed-queue-enabled
session-set	new arg seed-queue-size
torrent-get	new arg fromLpd in peersFrom
torrent-get	new arg isStalled
torrent-get	new arg queuePosition
torrent-set	new arg queuePosition
torrent-start-now	new method

Transmission 2.80 (rpc-version-semver 5.1.0, rpc-version: 15)

Method	Description
torrent-get	new arg etaIdle
torrent-rename-path	new method
free-space	new method
torrent-add	new return arg torrent-duplicate

Transmission 3.00 (rpc-version-semver 5.2.0, rpc-version: 16)

Method	Description
session-get	new request arg fields
session-get	new arg session-id
torrent-get	new arg labels
torrent-set	new arg labels
torrent-get	new arg editDate
torrent-get	new request arg format

Transmission 4.0.0 (rpc-version-semver 5.3.0, rpc-version: 17)

Method	Description
/upload	:warning: undocumented /upload endpoint removed
session-get	:warning: DEPRECATED download-dir-free-space. Use free-space instead.
free-space	new return arg total_size
session-get	new arg default-trackers
session-get	new arg rpc-version-semver
session-get	new arg script-torrent-added-enabled
session-get	new arg script-torrent-added-filename
session-get	new arg script-torrent-done-seeding-enabled
session-get	new arg script-torrent-done-seeding-filename
torrent-add	new arg labels
torrent-get	new arg availability
torrent-get	new arg file-count
torrent-get	new arg group
torrent-get	new arg percentComplete
torrent-get	new arg primary-mime-type

Transmission 4.1.0 (rpc_version_semver 6.0.0, rpc_version: 18)

:bomb: switch to the JSON-RPC 2.0 protocol :bomb: switch to snake_case for all strings

Method	Description
session_get	new arg sequential_download
session_set	new arg sequential_download
torrent_add	new arg sequential_download
torrent_get	new arg sequential_download
torrent_set	new arg sequential_download
torrent_add	new arg sequential_download_from_piece
torrent_get	new arg sequential_download_from_piece
torrent_set	new arg sequential_download_from_piece
torrent_get	new arg files.begin_piece
torrent_get	new arg files.end_piece
port_test	new arg ip_protocol
torrent_get	new arg tracker_stats.downloader_count
torrent_get	:warning: DEPRECATED manual_announce_time, it never worked
session_get	new arg preferred_transports
session_set	new arg preferred_transports

Transmission 4.1.1 (rpc_version_semver 6.0.1, rpc_version: 19)

Method	Description
session_get	speed_limit_down reverted to return an integer
session_get	speed_limit_up reverted to return an integer
group_get	speed_limit_down reverted to return an integer
group_get	speed_limit_up reverted to return an integer

Transmission 4.2.0 (rpc_version_semver 6.1.0, rpc_version: ?)

Method	Description
torrent_get	new arg webseeds_ex
torrent_get	DEPRECATED webseeds. Use webseeds_ex instead.
session_get	DEPRECATED cache_size_mib. The memory cache is being removed, making this setting moot. The setting will still be gettable and settable via RPC session_get and session_set until Transmission 5.0.0 to avoid client breakage, but it will be otherwise unused in libtransmission. Clients should stop using this key.

Reference

• https://raw.githubusercontent.com/transmission/transmission/refs/heads/main/docs/rpc-spec.md