multiformats/go-multiaddr

Composable and future-proof network addresses

297

stars

584

commits

Go

primary language

Feb 23, 2026

updated

github.com/multiformats/multiaddrBrowse cluster: IPFS, libp2p, and distributed networking

README

go-multiaddr

GoDoc Travis CI codecov.io

multiaddr implementation in go

Multiaddr is a standard way to represent addresses that:

  • Support any standard network protocols.
  • Self-describe (include protocols).
  • Have a binary packed format.
  • Have a nice string representation.
  • Encapsulate well.

Table of Contents

Install

go get github.com/multiformats/go-multiaddr

Usage

Example

Simple

import ma "github.com/multiformats/go-multiaddr"

// construct from a string (err signals parse failure)
m1, err := ma.NewMultiaddr("/ip4/127.0.0.1/udp/1234")

// construct from bytes (err signals parse failure)
m2, err := ma.NewMultiaddrBytes(m1.Bytes())

// true
strings.Equal(m1.String(), "/ip4/127.0.0.1/udp/1234")
strings.Equal(m1.String(), m2.String())
bytes.Equal(m1.Bytes(), m2.Bytes())
m1.Equal(m2)
m2.Equal(m1)

Protocols

// get the multiaddr protocol description objects
m1.Protocols()
// []Protocol{
//   Protocol{ Code: 4, Name: 'ip4', Size: 32},
//   Protocol{ Code: 17, Name: 'udp', Size: 16},
// }

En/decapsulate

import ma "github.com/multiformats/go-multiaddr"

m, err := ma.NewMultiaddr("/ip4/127.0.0.1/udp/1234")
// <Multiaddr /ip4/127.0.0.1/udp/1234>

sctpMA, err := ma.NewMultiaddr("/sctp/5678")

m.Encapsulate(sctpMA)
// <Multiaddr /ip4/127.0.0.1/udp/1234/sctp/5678>

udpMA, err := ma.NewMultiaddr("/udp/1234")

m.Decapsulate(udpMA) // up to + inc last occurrence of subaddr
// <Multiaddr /ip4/127.0.0.1>

Tunneling

Multiaddr allows expressing tunnels very nicely.

printer, _ := ma.NewMultiaddr("/ip4/192.168.0.13/tcp/80")
proxy, _ := ma.NewMultiaddr("/ip4/10.20.30.40/tcp/443")
printerOverProxy := proxy.Encapsulate(printer)
// /ip4/10.20.30.40/tcp/443/ip4/192.168.0.13/tcp/80

proxyAgain := printerOverProxy.Decapsulate(printer)
// /ip4/10.20.30.40/tcp/443

Contribute

Contributions welcome. Please check out the issues.

Check out our contributing document for more information on how we work, and about contributing in general. Please be aware that all interactions related to multiformats are subject to the IPFS Code of Conduct.

Small note: If editing the README, please conform to the standard-readme specification.

License

MIT © 2014 Juan Batiz-Benet

Contributors

(top 30 of 41)

Stebalien

145 commits

jbenet

97 commits

whyrusleeping

54 commits

marten-seemann

52 commits

multiformats/go-multiaddr

Composable and future-proof network addresses

297

stars

584

commits

Go

primary language

Feb 23, 2026

updated

github.com/multiformats/multiaddrBrowse cluster: IPFS, libp2p, and distributed networking

README

go-multiaddr

GoDoc Travis CI codecov.io

multiaddr implementation in go

Multiaddr is a standard way to represent addresses that:

  • Support any standard network protocols.
  • Self-describe (include protocols).
  • Have a binary packed format.
  • Have a nice string representation.
  • Encapsulate well.

Table of Contents

Install

go get github.com/multiformats/go-multiaddr

Usage

Example

Simple

import ma "github.com/multiformats/go-multiaddr"

// construct from a string (err signals parse failure)
m1, err := ma.NewMultiaddr("/ip4/127.0.0.1/udp/1234")

// construct from bytes (err signals parse failure)
m2, err := ma.NewMultiaddrBytes(m1.Bytes())

// true
strings.Equal(m1.String(), "/ip4/127.0.0.1/udp/1234")
strings.Equal(m1.String(), m2.String())
bytes.Equal(m1.Bytes(), m2.Bytes())
m1.Equal(m2)
m2.Equal(m1)

Protocols

// get the multiaddr protocol description objects
m1.Protocols()
// []Protocol{
//   Protocol{ Code: 4, Name: 'ip4', Size: 32},
//   Protocol{ Code: 17, Name: 'udp', Size: 16},
// }

En/decapsulate

import ma "github.com/multiformats/go-multiaddr"

m, err := ma.NewMultiaddr("/ip4/127.0.0.1/udp/1234")
// <Multiaddr /ip4/127.0.0.1/udp/1234>

sctpMA, err := ma.NewMultiaddr("/sctp/5678")

m.Encapsulate(sctpMA)
// <Multiaddr /ip4/127.0.0.1/udp/1234/sctp/5678>

udpMA, err := ma.NewMultiaddr("/udp/1234")

m.Decapsulate(udpMA) // up to + inc last occurrence of subaddr
// <Multiaddr /ip4/127.0.0.1>

Tunneling

Multiaddr allows expressing tunnels very nicely.

printer, _ := ma.NewMultiaddr("/ip4/192.168.0.13/tcp/80")
proxy, _ := ma.NewMultiaddr("/ip4/10.20.30.40/tcp/443")
printerOverProxy := proxy.Encapsulate(printer)
// /ip4/10.20.30.40/tcp/443/ip4/192.168.0.13/tcp/80

proxyAgain := printerOverProxy.Decapsulate(printer)
// /ip4/10.20.30.40/tcp/443

Contribute

Contributions welcome. Please check out the issues.

Check out our contributing document for more information on how we work, and about contributing in general. Please be aware that all interactions related to multiformats are subject to the IPFS Code of Conduct.

Small note: If editing the README, please conform to the standard-readme specification.

License

MIT © 2014 Juan Batiz-Benet

Contributors

(top 30 of 41)

Stebalien

145 commits

jbenet

97 commits

whyrusleeping

54 commits

marten-seemann

52 commits

Languages

Go

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