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4.1.0 • Public • Published


CI NPM version js-standard-style

Determine address of proxied request.

Forked from https://github.com/jshttp/proxy-addr to address https://github.com/jshttp/forwarded/pull/9.


$ npm i @fastify/proxy-addr


var proxyaddr = require('@fastify/proxy-addr')

proxyaddr(req, trust)

Return the address of the request, using the given trust parameter.

The trust argument is a function that returns true if you trust the address, false if you don't. The closest untrusted address is returned.

proxyaddr(req, function (addr) { return addr === '' })
proxyaddr(req, function (addr, i) { return i < 1 })

The trust arugment may also be a single IP address string or an array of trusted addresses, as plain IP addresses, CIDR-formatted strings, or IP/netmask strings.

proxyaddr(req, '')
proxyaddr(req, ['', ''])
proxyaddr(req, ['', ''])

This module also supports IPv6. Your IPv6 addresses will be normalized automatically (i.e. fe80::00ed:1 equals fe80:0:0:0:0:0:ed:1).

proxyaddr(req, '::1')
proxyaddr(req, ['::1/128', 'fe80::/10'])

This module will automatically work with IPv4-mapped IPv6 addresses as well to support node.js in IPv6-only mode. This means that you do not have to specify both ::ffff:a00:1 and

As a convenience, this module also takes certain pre-defined names in addition to IP addresses, which expand into IP addresses:

proxyaddr(req, 'loopback')
proxyaddr(req, ['loopback', 'fc00:ac:1ab5:fff::1/64'])
  • loopback: IPv4 and IPv6 loopback addresses (like ::1 and
  • linklocal: IPv4 and IPv6 link-local addresses (like fe80::1:1:1:1 and
  • uniquelocal: IPv4 private addresses and IPv6 unique-local addresses (like fc00:ac:1ab5:fff::1 and

When trust is specified as a function, it will be called for each address to determine if it is a trusted address. The function is given two arguments: addr and i, where addr is a string of the address to check and i is a number that represents the distance from the socket address.

proxyaddr.all(req, [trust])

Return all the addresses of the request, optionally stopping at the first untrusted. This array is ordered from closest to furthest (i.e. arr[0] === req.connection.remoteAddress).


The optional trust argument takes the same arguments as trust does in proxyaddr(req, trust).

proxyaddr.all(req, 'loopback')


Compiles argument val into a trust function. This function takes the same arguments as trust does in proxyaddr(req, trust) and returns a function suitable for proxyaddr(req, trust).

var trust = proxyaddr.compile('loopback')
var addr = proxyaddr(req, trust)

This function is meant to be optimized for use against every request. It is recommend to compile a trust function up-front for the trusted configuration and pass that to proxyaddr(req, trust) for each request.


$ npm test


$ npm run-script bench



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npm i @fastify/proxy-addr

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