Magnet URI on:
[Wikipedia]
[Google]
[Amazon]
Magnet is a
(
(
Magnet is a URI scheme
A Uniform Resource Identifier (URI), formerly Universal Resource Identifier, is a unique sequence of characters that identifies an abstract or physical resource, such as resources on a webpage, mail address, phone number, books, real-world obje ...
that defines the format of magnet links, a de facto standard
A ''de facto'' standard is a custom or convention that is commonly used even though its use is not required.
is a Latin phrase (literally " of fact"), here meaning "in practice but not necessarily ordained by law" or "in practice or actuality, ...
for identifying files (URN
An urn is a vase, often with a cover, with a typically narrowed neck above a rounded body and a footed pedestal. Describing a vessel as an "urn", as opposed to a vase or other terms, generally reflects its use rather than any particular shape ...
) by their content, via cryptographic hash value rather than by their location.
#
Although magnet links can be used in a number of contexts, they are particularly useful in peer-to-peer file sharing
Peer-to-peer file sharing is the distribution and sharing of digital media using peer-to-peer (P2P) networking technology. P2P file sharing allows users to access media files such as books, music, movies, and games using a P2P software program th ...
networks because they allow resources to be referred to without the need for a continuously available host, and can be generated by anyone who already has the file, without the need for a central authority to issue them. This makes them popular for use as "guaranteed" search terms within the file sharing
File sharing is the practice of distributing or providing access to digital media, such as computer programs, multimedia (audio, images and video), documents or electronic books. Common methods of storage, transmission and dispersion include ...
community where anyone can distribute a magnet link to ensure that the resource retrieved by that link is the one intended, regardless of how it is retrieved.
History
The standard for MagnetURI
Uri may refer to:
Places
* Canton of Uri, a canton in Switzerland
* Úri, a village and commune in Hungary
* Uri, Iran, a village in East Azerbaijan Province
* Uri, Jammu and Kashmir, a town in India
* Uri (island), off Malakula Island in V ...
s was developed by Bitzi in 2002, partly as a "vendor- and project-neutral generalization" of the ed2k: and freenet: URI schemes used by eDonkey2000
eDonkey2000 (nicknamed "ed2k") was a peer-to-peer file sharing application developed by US company MetaMachine ( Jed McCaleb and Sam Yagan), using the Multisource File Transfer Protocol. It supported both the eDonkey2000 network and the Over ...
and Freenet
Hyphanet (until mid-2023: Freenet) is a peer-to-peer platform for censorship-resistant, Anonymity application, anonymous communication. It uses a decentralized distributed data store to keep and deliver information, and has a suite of free soft ...
(now Hyphanet), respectively, and attempts to follow official IETF
The Internet Engineering Task Force (IETF) is a standards organization for the Internet standard, Internet and is responsible for the technical standards that make up the Internet protocol suite (TCP/IP). It has no formal membership roster ...
URI
Uri may refer to:
Places
* Canton of Uri, a canton in Switzerland
* Úri, a village and commune in Hungary
* Uri, Iran, a village in East Azerbaijan Province
* Uri, Jammu and Kashmir, a town in India
* Uri (island), off Malakula Island in V ...
standards as closely as possible. BitTorrent
BitTorrent is a Protocol (computing), communication protocol for peer-to-peer file sharing (P2P), which enables users to distribute data and electronic files over the Internet in a Decentralised system, decentralized manner. The protocol is d ...
introduced the btmh: protocol in 2020 as part of its BitTorrent v2 changes.
Format
Magnet URIs consist of a series of one or more parameters, the order of which is not significant, formatted in the same way asquery string
A query string is a part of a uniform resource locator ( URL) that assigns values to specified parameters. A query string commonly includes fields added to a base URL by a Web browser or other client application, for example as part of an HTML doc ...
s that ordinarily terminate HTTP
HTTP (Hypertext Transfer Protocol) is an application layer protocol in the Internet protocol suite model for distributed, collaborative, hypermedia information systems. HTTP is the foundation of data communication for the World Wide Web, wher ...
URLs.
The following parameters are supported:
The standard also allows for application-specific experimental parameters, which must begin with "x".
Exact Topic (xt)
The xt parameter specifies the URN for a given p2p protocol. Its purpose is to provide a search parameter for finding the metadata to the torrent. This effectively acts as a replacement to a .torrent file, which itself contains the torrent metadata, by instead searching the p2p network (using the URN) for that metadata. Each protocol handles a URN uniquely; for example,xt=urn:btih:FFC7E738EAA4CD4ECF51EC6FD669C6CDE2C281A8 uses the btih (BitTorrent v1 protocol), so a BitTorrent client can take the hash and lookup the torrent's metadata in the BitTorrent DHT. In the case of DHT the client searches through a set of pre-known nodes and requests the metadata for an infohash; those nodes will make the same request to other known nodes until eventually a swarm is found and returned.
xt also allows for a group setting. Multiple files can be included by adding a count number preceded by a dot (".") to each link parameter.
:magnet:?xt.1= [ URN
An urn is a vase, often with a cover, with a typically narrowed neck above a rounded body and a footed pedestal. Describing a vessel as an "urn", as opposed to a vase or other terms, generally reflects its use rather than any particular shape ...
of the first file]&xt.2=[ URN of the second file]xt=urn:tree:tiger : TTH hash sum">Hash
Hash, hashes, hash mark, or hashing may refer to:
Substances
* Hash (food), a coarse mixture of ingredients, often based on minced meat
* Hash (stew), a pork and onion-based gravy found in South Carolina
* Hash, a nickname for hashish, a canna ...
Base32
Base32 is an encoding method based on the Radix, base-32 numeral system. It uses an alphabet of 32 Numerical digit, digits, each of which represents a different combination of 5 bits (25). Since base32 is not very widely adopted, the question of no ...
) ]
; SHA-1, Secure Hash Algorithm 1 (SHA-1): These hash sums are used on gnutella
Gnutella is a peer-to-peer network protocol. Founded in 2000, it was the first decentralized peer-to-peer network of its kind, leading to other, later networks adopting the model.
In June 2005, Gnutella's population was 1.81 million computer ...
and G2 (Gnutella2).
:xt=urn:sha1 : SHA-1 hash function">Hash
Hash, hashes, hash mark, or hashing may refer to:
Substances
* Hash (food), a coarse mixture of ingredients, often based on minced meat
* Hash (stew), a pork and onion-based gravy found in South Carolina
* Hash, a nickname for hashish, a canna ...
Base32
Base32 is an encoding method based on the Radix, base-32 numeral system. It uses an alphabet of 32 Numerical digit, digits, each of which represents a different combination of 5 bits (25). Since base32 is not very widely adopted, the question of no ...
) ]
; BitPrint: Such hash sums consist of an SHA-1 Hash, followed by a TTH Hash, delimited by a point; they are used on gnutella
Gnutella is a peer-to-peer network protocol. Founded in 2000, it was the first decentralized peer-to-peer network of its kind, leading to other, later networks adopting the model.
In June 2005, Gnutella's population was 1.81 million computer ...
and G2 (Gnutella2).
:xt=urn:bitprint : SHA-1 hash function">Hash
Hash, hashes, hash mark, or hashing may refer to:
Substances
* Hash (food), a coarse mixture of ingredients, often based on minced meat
* Hash (stew), a pork and onion-based gravy found in South Carolina
* Hash, a nickname for hashish, a canna ...
(Base32
Base32 is an encoding method based on the Radix, base-32 numeral system. It uses an alphabet of 32 Numerical digit, digits, each of which represents a different combination of 5 bits (25). Since base32 is not very widely adopted, the question of no ...
) ]. TTH hash sum">Hash
Hash, hashes, hash mark, or hashing may refer to:
Substances
* Hash (food), a coarse mixture of ingredients, often based on minced meat
* Hash (stew), a pork and onion-based gravy found in South Carolina
* Hash, a nickname for hashish, a canna ...
(Base32
Base32 is an encoding method based on the Radix, base-32 numeral system. It uses an alphabet of 32 Numerical digit, digits, each of which represents a different combination of 5 bits (25). Since base32 is not very widely adopted, the question of no ...
) ]
; EDonkey network#Hash identification, ED2K (eDonkey2000) hash: These hash sums are used on eDonkey2000
eDonkey2000 (nicknamed "ed2k") was a peer-to-peer file sharing application developed by US company MetaMachine ( Jed McCaleb and Sam Yagan), using the Multisource File Transfer Protocol. It supported both the eDonkey2000 network and the Over ...
.
:xt=urn:ed2k :[ EDonkey network#Hash identification, ED2K hash sum, Hash (Hex
Hex usually refers to:
* A curse or supposed real and potentially supernaturally realized malicious wish
* Hexadecimal, a base-16 number system often used in computer nomenclature
Hex, HEX, or The Hex may also refer to:
Magic
* Hex sign, a b ...
) ]
; AICH, Advanced Intelligent Corruption Handler (AICH): Not formal URNs for Magnet links, such hash sums are used by eDonkey2000
eDonkey2000 (nicknamed "ed2k") was a peer-to-peer file sharing application developed by US company MetaMachine ( Jed McCaleb and Sam Yagan), using the Multisource File Transfer Protocol. It supported both the eDonkey2000 network and the Over ...
to restore and control the integrity of downloading and already downloaded files.
:xt=urn:aich : AICH, aich hash sum, Hash (Base32
Base32 is an encoding method based on the Radix, base-32 numeral system. It uses an alphabet of 32 Numerical digit, digits, each of which represents a different combination of 5 bits (25). Since base32 is not very widely adopted, the question of no ...
) ]
; Kazaa hash: Used on FastTrack, these hash sums are vulnerable to Collision attack, hash collision attacks.
:xt=urn:kzhash :[ Kazaa hash sum, Hash (Hex
Hex usually refers to:
* A curse or supposed real and potentially supernaturally realized malicious wish
* Hexadecimal, a base-16 number system often used in computer nomenclature
Hex, HEX, or The Hex may also refer to:
Magic
* Hex sign, a b ...
) ]
; BitTorrent info hash (BTIH): These are hex-encoded SHA-1
In cryptography, SHA-1 (Secure Hash Algorithm 1) is a hash function which takes an input and produces a 160-bit (20-byte) hash value known as a message digest – typically rendered as 40 hexadecimal digits. It was designed by the United States ...
hash sums of the "info" sections of BitTorrent metafiles as used by BitTorrent
BitTorrent is a Protocol (computing), communication protocol for peer-to-peer file sharing (P2P), which enables users to distribute data and electronic files over the Internet in a Decentralised system, decentralized manner. The protocol is d ...
to identify downloadable files or sets of files. For backwards compatibility with existing links, clients should also support the Base32
Base32 is an encoding method based on the Radix, base-32 numeral system. It uses an alphabet of 32 Numerical digit, digits, each of which represents a different combination of 5 bits (25). Since base32 is not very widely adopted, the question of no ...
encoded version of the hash.
:xt=urn:btih :[ BitTorrent
BitTorrent is a Protocol (computing), communication protocol for peer-to-peer file sharing (P2P), which enables users to distribute data and electronic files over the Internet in a Decentralised system, decentralized manner. The protocol is d ...
Info hash sum, Hash (Hex
Hex usually refers to:
* A curse or supposed real and potentially supernaturally realized malicious wish
* Hexadecimal, a base-16 number system often used in computer nomenclature
Hex, HEX, or The Hex may also refer to:
Magic
* Hex sign, a b ...
) ]
: Some clients require Base32
Base32 is an encoding method based on the Radix, base-32 numeral system. It uses an alphabet of 32 Numerical digit, digits, each of which represents a different combination of 5 bits (25). Since base32 is not very widely adopted, the question of no ...
of info_hash (e.g., Vuze
Vuze (previously Azureus) is a BitTorrent client used to transfer files via the BitTorrent protocol. Vuze is written in Java, and uses the Azureus Engine. In addition to downloading data linked to .torrent files, Azureus allows users to view, p ...
).
; BitTorrent info hash v2 (BTMH): BitTorrent v2 replaces the obsolete SHA-1 hash with a SHA-256
SHA-2 (Secure Hash Algorithm 2) is a set of cryptographic hash functions designed by the United States National Security Agency (NSA) and first published in 2001. They are built using the Merkle–Damgård construction, from a one-way compressi ...
info hash. The v2 info-hash is given a new prefix (btmh) to allow for torrents that can participate in both v1 and v2 swarms.
:xt=urn:btmh :[1220: (v2 prefix) BitTorrent
BitTorrent is a Protocol (computing), communication protocol for peer-to-peer file sharing (P2P), which enables users to distribute data and electronic files over the Internet in a Decentralised system, decentralized manner. The protocol is d ...
Info hash sum, Hash (Hex
Hex usually refers to:
* A curse or supposed real and potentially supernaturally realized malicious wish
* Hexadecimal, a base-16 number system often used in computer nomenclature
Hex, HEX, or The Hex may also refer to:
Magic
* Hex sign, a b ...
) ]
; MD5, Message Digest 5 (MD5): Supported by G2 (Gnutella2), such hashes are vulnerable to Collision attack, hash collision attacks.
:xt=urn:md5 : MD5 hash sum, Hash (Hex
Hex usually refers to:
* A curse or supposed real and potentially supernaturally realized malicious wish
* Hexadecimal, a base-16 number system often used in computer nomenclature
Hex, HEX, or The Hex may also refer to:
Magic
* Hex sign, a b ...
) ]
Web links to the file
There are two types of download links that a Magnet link can include as a direct or backup source. ; "as" ("acceptable source"): Most clients treat "as" as equal to the "xs" token when it comes to priority, and ignore the timeout before contacting "as" sources denoted by the specs. ; Content-Addressable Web URL: This type of -based link is used bygnutella
Gnutella is a peer-to-peer network protocol. Founded in 2000, it was the first decentralized peer-to-peer network of its kind, leading to other, later networks adopting the model.
In June 2005, Gnutella's population was 1.81 million computer ...
as well as G2 applications.
:xs=http:// lient Address ort of clienturi-res/N2R?URN
An urn is a vase, often with a cover, with a typically narrowed neck above a rounded body and a footed pedestal. Describing a vessel as an "urn", as opposed to a vase or other terms, generally reflects its use rather than any particular shape ...
containing a file hash sum">hash
Hash, hashes, hash mark, or hashing may refer to:
Substances
* Hash (food), a coarse mixture of ingredients, often based on minced meat
* Hash (stew), a pork and onion-based gravy found in South Carolina
* Hash, a nickname for hashish, a canna ...
]
:xs=http://192.0.2.27:6346/uri-res/N2R?urn:sha1:FINYVGHENTHSMNDSQQYDNLPONVBZTICF
;Link to a DirectConnect hub to find sources for a file: This type of link connects a DirectConnect client immediately to the hub in question.
:xs=dchub:// ub address ub port/code>
;Reference to a web-based source cache for a file on Gnutella2
Gnutella2, often referred to as G2, is a peer-to-peer protocol developed mainly by Michael Stokes and released in 2002.
While inspired by the gnutella protocol, G2 shares little of its design with the exception of its connection handshake and ...
: In this case, the included link points, not to a client IP or direct source, but to a source cache which stores the IPs of other clients contacting it to download the same file. Once a client connects to the cache, it is served IPs for alternate sources, while its own IP is stored within the cache and forwarded to the next one connecting to the cache. This system operates similar to a BitTorrent tracker
A BitTorrent tracker is a special type of server that assists in the communication between peers using the BitTorrent protocol.
In peer-to-peer file sharing, a software client on an end-user PC requests a file, and portions of the requested ...
.
:xs=http://cache.freebase.be/ SHA-1 hash sum">hash
Hash, hashes, hash mark, or hashing may refer to:
Substances
* Hash (food), a coarse mixture of ingredients, often based on minced meat
* Hash (stew), a pork and onion-based gravy found in South Carolina
* Hash, a nickname for hashish, a canna ...
]
;Reference to an eD2k source
:xs=ed2kftp://[client address]:[client port]/[ed2k hash]/[file size]/
Supplement format (x.)
For experimental and self-complementing informal options, the prefix followed by a chosen suffix letter can be used. These names are guaranteed to never be standardized.
:x. ame of the new parameter ata of the new parameter (URL encoded)">URL.html" ;"title="ata of the new parameter (URL">ata of the new parameter (URL encoded)/code>
Clients
See also
* BitTorrent
BitTorrent is a Protocol (computing), communication protocol for peer-to-peer file sharing (P2P), which enables users to distribute data and electronic files over the Internet in a Decentralised system, decentralized manner. The protocol is d ...
* Burnbit
* ed2k URI scheme
* InterPlanetary File System
* Metalink
* Named data networking
* Peer-to-peer
Explanatory notes
References
External links
* , an early definition of the format (last update 2002)
CHK
Freeware checksum utility with SHA1-Base32 and ED2K support
* , an open source
Open source is source code that is made freely available for possible modification and redistribution. Products include permission to use and view the source code, design documents, or content of the product. The open source model is a decentrali ...
command-line tool, which can calculate magnet links
{{DEFAULTSORT:Magnet Uri Scheme
File sharing
URI schemes