1.\"
  2.\" Copyright (c) 2019 Ted Unangst
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 16.Dd $Mdocdate$
 17.Dt ACTIVITYPUB 7
 18.Os
 19.Sh NAME
 20.Nm activitypub
 21.Nd notes about the honk implementation
 22.Sh DESCRIPTION
 23The
 24.Xr honk 1
 25utility processes status updates and other microblog activities using the
 26.Nm ActivityPub
 27protocol to exchange messages with other servers.
 28The specification is subject to interpretation, and not all implementations
 29behave in the same way.
 30This document attempts to clarify honk's behavior.
 31It is not intended to be a complete description of
 32.Nm ActivityPub ,
 33but may be useful as a guide to other implementors looking to interoperate.
 34.Ss OBJECTS
 35The following object or document types are supported.
 36.Bl -tag -width tenletters
 37.It Vt Note
 38Fully supported.
 39The default object type for honk.
 40.It Vt Article
 41Fully supported.
 42.It Vt Page
 43Supported.
 44.It Vt Question
 45Read only support.
 46Appears similar to a Note.
 47.It Vt Event
 48Supported.
 49Appears similar to a Note.
 50Can be both created and received, but
 51.Vt Invite
 52activities are ignored.
 53.It Vt Video
 54Limited support.
 55.It Vt Audio
 56Limited Support.
 57.It Vt GuessWord
 58Guess the word game.
 59(Unofficial extension.)
 60The solution is stored in
 61.Fa content
 62with the possible words, one per line, in a file located at
 63.Fa wordlist .
 64.El
 65.Pp
 66Honk primarily supports HTML content, not markdown or other formats,
 67with a wide range of permitted HTML tags in object
 68.Fa content
 69fields.
 70The following tags are supported.
 71.Bd -literal -offset indent
 72a, img, span,
 73div, h1, h2, h3, h4, h5, h6, hr,
 74table, thead, tbody, tfoot, th, tr, td, colgroup, col,
 75p, br, pre, code, blockquote, q,
 76caption, kbd, time, wbr, aside,
 77ruby, rtc, rb, rt, details, summary,
 78samp, mark, ins, dfn, cite, abbr, address,
 79strong, em, b, i, s, u, sub, sup, del, tt, small,
 80ol, ul, li, dl, dt, dd
 81.Ed
 82.Pp
 83The following tag attributes are permitted.
 84.Bd -literal -offset indent
 85href, src, alt, colspan, rowspan
 86.Ed
 87.Pp
 88The following class names are used for syntax highlighting code blocks.
 89.Bd -literal -offset indent
 90kw, bi, st, nm, tp, op, cm, al, dl
 91.Ed
 92.Ss ACTIVITIES
 93The following activities are supported.
 94.Bl -tag -width tenletters
 95.It Vt Create
 96Fully supported.
 97.It Vt Announce
 98Supported with share semantics.
 99.It Vt Read
100Supported.
101Primarily used to acknowledge replies and complete threads.
102Can be interpreted to mean reply is approved, if not endorsed.
103.It Vt Add
104Works with collections.
105.It Vt Follow
106Supported.
107Can follow both actors and collections.
108.It Vt Update
109Supported.
110Honk sends and receives
111.Vt Update
112activities.
113.It Vt Delete
114Does what it can.
115.It Vt Like
116Don't be ridiculous.
117.It Vt EmojiReact
118Be ridiculous.
119.El
120.Ss METADATA
121The following additional object types are supported, typically as
122.Fa tag
123or
124.Fa attachment .
125.Bl -tag -width tenletters
126.It Mention
127Pretty @ machine.
128.It Emoji
129Inline text :emoji: with image replacement.
130.It Place
131Included as a
132.Fa location .
133Supports
134.Fa name ,
135.Fa url ,
136.Fa latitude ,
137and
138.Fa longitude .
139.It Document
140Plain text and images in jpeg, gif, png, and webp formats are supported.
141Other formats are linked to origin.
142.El
143.Pp
144The
145.Fa replies
146array will be populated with a list of acknowledged replies.
147.Ss EXTENSIONS
148Honk also supports a
149.Vt Ping
150activity and will respond with a
151.Vt Pong
152activity.
153This is useful for debugging networking connectivity issues without
154visible side effects.
155See ping.txt for details.
156.Ss SECURITY
157Honk uses http signatures.
158.Ss WEBFINGER
159Honk implements the
160.Vt webfinger
161end point and will use it for @mention resolution.
162It is not required for federation.
163.Ss LD-JSON
164Not really.
165.Sh SEE ALSO
166.Xr intro 1 ,
167.Xr honk 1
168.Sh STANDARDS
169.Pp
170.Lk https://www.w3.org/TR/activitypub/ "ActivityPub"
171.Pp
172.Lk https://www.w3.org/TR/activitystreams-vocabulary/ "Activity Vocabulary"
173.Sh CAVEATS
174The ActivityPub standard is subject to interpretation, and not all
175implementations are as enlightened as honk.