ACTIVITYPUB(7)

NAME
activitypub - notes about the honk implementation

DESCRIPTION
The honk(1) utility processes status updates and other microblog activities using the ActivityPub protocol to exchange messages with other servers. The specification is subject to interpretation, and not all implementations behave in the same way. This document attempts to clarify honk's behavior. It is not intended to be a complete description of ActivityPub, but may be useful as a guide to other implementors looking to interoperate.

  OBJECTS
The following object or document types are supported.

Note
    Fully supported. The default object type for honk.

Article
    Fully supported.

Page
    Supported.

Question
    Read only support. Appears similar to a Note.

Event
    Supported. Appears similar to a Note. Can be both created and received, but Invite activities are ignored.

Video
    Limited support.

Audio
    Limited Support.

Honk primarily supports HTML content, not markdown or other formats, with a wide range of permitted HTML tags in object content fields. The following tags are supported.

    a, img, span,
    div, h1, h2, h3, h4, h5, h6, hr,
    table, thead, tbody, tfoot, th, tr, td, colgroup, col,
    p, br, pre, code, blockquote, q,
    caption, kbd, time, wbr, aside,
    ruby, rtc, rb, rt, details, summary,
    samp, mark, ins, dfn, cite, abbr, address,
    strong, em, b, i, s, u, sub, sup, del, tt, small,
    ol, ul, li, dl, dt, dd

The following tag attributes are permitted.

    href, src, alt, colspan, rowspan

The following class names are used for syntax highlighting code blocks.

    kw, bi, st, nm, tp, op, cm, al, dl

  ACTIVITIES
The following activities are supported.

Create
    Fully supported.

Announce
    Supported with share semantics.

Read
    Supported. Primarily used to acknowledge replies and complete threads. Can be interpreted to mean reply is approved, if not endorsed.

Add Works with collections.

Follow
    Supported. Can follow both actors and collections. Accept and Undo require that the original request be quoted, not referred to by URI.

Update
    Supported. Honk sends and receives Update activities.

Delete
    Does what it can.

Like
    Don't be ridiculous.

EmojiReact
    Be ridiculous.

  METADATA
The following additional object types are supported, typically as tag or attachment.

Mention
    Pretty @ machine.

Emoji
    Inline text :emoji: with image replacement.

Place
    Included as a location. Supports name, url, latitude, and longitude.

Document
    Plain text and images in jpeg, gif, png, and webp formats are supported. Other formats are linked to origin.

The replies array will be populated with a list of acknowledged replies.

  EXTENSIONS
Honk also supports a Ping activity and will respond with a Pong activity. This is useful for debugging networking connectivity issues without visible side effects. See ping.txt for details.

  SECURITY
Honk uses http signatures.

  WEBFINGER
Honk implements the webfinger end point and will use it for @mention resolution. It is not required for federation.

  LD-JSON
Not really.

SEE ALSO
intro(1), honk(1)

STANDARDS

ActivityPub: https://www.w3.org/TR/activitypub/

Activity Vocabulary: https://www.w3.org/TR/activitystreams-vocabulary/

CAVEATS
The ActivityPub standard is subject to interpretation, and not all implementations are as enlightened as honk.