Fediverse Protocol: following

This document gives an overview the process used to follow someone (or something) on the Fediverse.

What it describes is the idealized process.

When a particular Fediverse software does not implement a step described in this document, it is mentioned.

Table of Contents

• Step 0: Actor
• Step 1: DNS SRV
• Step 2: Web Host Metadata
• Step 3: WebFinger
• Step 4:

Step 0: Actor

People on the Fediverse are identified with identifiers that look like these:

• @joeblow@example.com
• @janedoe@apple.banana.cherry.social
• @dariush@changelog.ca

There are 2 parts of these identifiers —

1. actor name, and
2. host.

Let's take a look at an example to help make this clearer:

  @dariush@changelog.ca
   \--+--/ \-----+----/
      |          |
actor name      host

In this example —

• the actor name is dariush, and
• the host is changelog.ca

Let's look at another example:

  @joeblow@example.com
   \--+--/ \----+----/
      |         |
actor name     host

In this example —

• the actor name is joeblow, and
• the host is example.com

Here are a number of other examples:

Actor	Actor Name	Host
@joeblow@example.com	joeblow	example.com
@janedoe@apple.banana.cherry.social	janedoe	apple.banana.cherry.social
@dariush@changelog.ca	dariush	changelog.ca
@malekeh@social.example.net	malekeh	social.example.net
tom@apple.aaa	tom	apple.aaa
dick@banana.bbb	dick	banana.bbb
harry@cherry.ccc	harry	cherry.ccc

Now on to the next step....

Step 1: DNS SRV

The next step to follow someone on the Fediverse is —

Do a DNS SRV look-up on the host (you inferred in the previous), with protocol = "tcp" and service = "webfinger", to discover if the WebFinger is on this host or another host.

So, for example, if your actor identifier was:

@joeblow@example.com

Then that means that the actor name and host is as follows:

Actor	Actor Name	Host
@joeblow@example.com	joeblow	example.com

So then, a DNS SRV look-up on host = example.com with protocol = "tcp" and service = "webfinger" means we look-up _webfinger._tcp.example.com.

If something comes up, then that is the new value for host in the next step. If nothing came up, then keep the same value for host in the next step.

Step 2: Web Host Metadata