WebFinger

Logo of WebFinger

WebFinger is a protocol specified by the Internet Engineering Task Force IETF in RFC 7033 that allows for discovery of information about people and things identified by a URI.[1] Information about a person might be discovered via an acct: URI, for example, which is a URI that looks like an email address.

WebFinger is specified as the discovery protocol for OpenID Connect,[2] which is a protocol that allows one to more easily log in to various sites on the Internet.[3]

The WebFinger protocol is used by federated software, such as GNU social,[citation needed] Diaspora,[4] or Mastodon,[5] to discover users on federated nodes and pods, as well as the remoteStorage protocol.[6]

As a historical note, the name "WebFinger" is derived from the old ARPANET Finger protocol, but it is a very different protocol designed for HTTP.[7]

The protocol payload is represented in JSON format.

Example

Basic example with profile page and business card

Example format of a WebFinger JSON data model.

Client request: 

GET /.well-known/webfinger?resource=acct%3Abob%40example.com HTTP/1.1
Host: example.com

Server response: 

{
	"subject": "acct:[email protected]",
	"aliases": [
		"https://www.example.com/~bob/"
	],
	"properties": {
		"http://example.com/ns/role": "employee"
	},
	"links": [{
			"rel": "http://webfinger.example/rel/profile-page",
			"href": "https://www.example.com/~bob/"
		},
		{
			"rel": "http://webfinger.example/rel/businesscard",
			"href": "https://www.example.com/~bob/bob.vcf"
		}
	]
}

Usage on Mastodon

On Mastodon, any federated servers can look up users by sending a request to the WebFinger endpoint on other servers.[5] Here is an example for the user@[email protected]:

Client request:

GET /.well-known/webfinger?resource=acct%3AMastodon%40mastodon.social HTTP/1.1
Host: mastodon.social

Server response:

{
    "subject": "acct:[email protected]",
    "aliases": [
        "https://mastodon.social/@Mastodon",
        "https://mastodon.social/users/Mastodon"
    ],
    "links": [
        {
            "rel": "http://webfinger.net/rel/profile-page",
            "type": "text/html",
            "href": "https://mastodon.social/@Mastodon"
        },
        {
            "rel": "self",
            "type": "application/activity+json",
            "href": "https://mastodon.social/users/Mastodon"
        },
        {
            "rel": "http://ostatus.org/schema/1.0/subscribe",
            "template": "https://mastodon.social/authorize_interaction?uri={uri}"
        }
    ]
}

See also

References

  1. ^ Jones, Paul E.; Salgueiro, Gonzalo; Jones, Michael B.; Smarr, Joseph (September 2013). "RFC 7033: WebFinger".
  2. ^ "Final: OpenID Connect Discovery 1.0 incorporating errata set 1". openid.net. Retrieved 2022-12-19.
  3. ^ "OpenID Connect | OpenID". 2011-08-01. Retrieved 2022-12-19.
  4. ^ Clemens (2011-09-17). "How Diaspora Connects Users". Sarah Mei. Retrieved 2022-12-19.
  5. ^ a b "WebFinger - Mastodon documentation". docs.joinmastodon.org. Retrieved 2022-12-19.
  6. ^ remoteStorage protocol draft at the IETF website.
  7. ^ Introducing WebFinger