akkoma/FEDERATION.md

# Federation

## Supported federation protocols and standards

- [ActivityPub](https://www.w3.org/TR/activitypub/) (Server-to-Server)
- [WebFinger](https://webfinger.net/)
- [Http Signatures](https://datatracker.ietf.org/doc/html/draft-cavage-http-signatures)
- [NodeInfo](https://nodeinfo.diaspora.software/)

## Supported FEPs

- [FEP-67ff: FEDERATION](https://codeberg.org/fediverse/fep/src/branch/main/fep/67ff/fep-67ff.md)
- [FEP-dc88: Formatting Mathematics](https://codeberg.org/fediverse/fep/src/branch/main/fep/dc88/fep-dc88.md)
- [FEP-f1d5: NodeInfo in Fediverse Software](https://codeberg.org/fediverse/fep/src/branch/main/fep/f1d5/fep-f1d5.md)
- [FEP-fffd: Proxy Objects](https://codeberg.org/fediverse/fep/src/branch/main/fep/fffd/fep-fffd.md)
- [FEP-c16b: Formatting MFM functions](https://codeberg.org/fediverse/fep/src/branch/main/fep/c16b/fep-c16b.md)

## ActivityPub

Akkoma mostly follows the server-to-server parts of the ActivityPub standard,
but implements quirks for Mastodon compatibility as well as Mastodon-specific
and custom extensions.

See our documentation and Mastodon’s federation information
linked further below for details on these quirks and extensions.

Akkoma does not perform JSON-LD processing.

### Required extensions

#### HTTP Signatures
All AP S2S POST requests to Akkoma instances MUST be signed.
Depending on instance configuration the same may be true for GET requests.

### FEP-c16b: Formatting MFM functions

The optional extension term `htmlMfm` is currently not used.

## Nodeinfo

Akkoma provides many additional entries in its nodeinfo response,
see the documentation linked below for details.

## Additional documentation

- [Akkoma’s ActivityPub extensions](https://docs.akkoma.dev/develop/development/ap_extensions/)
- [Akkoma’s nodeinfo extensions](https://docs.akkoma.dev/develop/development/nodeinfo_extensions/)
- [Mastodon’s federation requirements](https://github.com/mastodon/mastodon/blob/main/FEDERATION.md)