#fep 1 hashtag

Todd Sundsted

Before creating and publishing FEDERATION.md for #ktistec I wanted to understand what existing practice looked like across the Fediverse.

FEP-67ff describes the requirements of the FEDERATION.md file in loose terms and provides a non-normative template. I scraped the URLs of FEDERATION.md files from FEP-67ff itself and confirmed I could fetch them. The FEP listed 30 accessible projects (31 total, but one project—FIRM—does not appear to exist).

If a file had a section with the heading "Supported FEPs" per the non-normative template, I only looked there for supported FEPs. Otherwise I scanned the entire document.

Implemented FEPs, ranked by the number of implementations that attest support, are:

FEP   Name                                                        #
----  ---------------------------------------------------------  --
67ff  FEDERATION.md                                              18
f1d5  NodeInfo in Fediverse Software                             16
8b32  Object Integrity Proofs                                     7
044f  Consent-respecting quote posts                              7
2677  Identifying the Application Actor                           7
e232  Object Links                                                6
1b12  Group federation                                            6
3b86  Activity Intents                                            6
521a  Representing actor's public keys                            5
2c59  Discovery of a Webfinger address from an ActivityPub actor  5
7888  Demystifying the context property                           5
5feb  Search indexing consent for actors                          5
4adb  Dereferencing identifiers with webfinger                    4
d556  Server-Level Actor Discovery Using WebFinger                4
fb2a  Actor metadata                                              4
ef61  Portable Objects                                            4
8fcf  Followers collection synchronization across servers         4
844e  Capability discovery                                        4
7628  Move actor                                                  3
61cf  The OpenWebAuth Protocol                                    3
c390  Identity Proofs                                             3
400e  Publicly-appendable ActivityPub collections                 3
c0e0  Emoji reactions                                             3
0151  NodeInfo in Fediverse Software (2025 edition)               3
fffd  Proxy Objects                                               2
f228  Backfilling conversations                                   2
fe34  Origin-based security model                                 2
eb48  Hashtags                                                    2
171b  Conversation Containers                                     2
a5c5  Web Syndication Methods                                     2

There are obvious flaws in the methodology. Or maybe in the data. Only 18 out of the 30 projects I could access had a FEDERATION.md that attested FEDERATION.md support. Only 19 mentioned "FEDERATION.md". Only 21 mentioned "67ff". The remaining projects clearly did support FEP-67ff—the file itself was evidence. (FEDERATION.md is not meant to be machine readable—there's an issue about that).

It was more difficult to rank implemented federation protocols. I extracted keywords from documents with a  "Supported federation protocols and standards" section and created a dictionary of terms. If a file had a section with the heading "Supported federation protocols and standards", I only looked there. Otherwise I scanned the entire document.

Feature            #
----------------  --
activitypub       26
webfinger         24
http_signatures   21
nodeinfo          19
json_ld            2
ld_signatures      2
ostatus            2
authorized_fetch   1
atproto            1

If time allows, I'm going to try to rank these documents by "utility", though I haven't yet determined the exact metric. These documents clearly provide valuable information, but their lack of standardization makes them harder to analyze systematically.

#ActivityPub #Fediverse #Fep67ff #fep