Chat: Allow posting without content if an attachment is present.
[akkoma] / docs / API / chats.md
1 # Chats
2
3 Chats are a way to represent an IM-style conversation between two actors. They are not the same as direct messages and they are not `Status`es, even though they have a lot in common.
4
5 ## Why Chats?
6
7 There are no 'visibility levels' in ActivityPub, their definition is purely a Mastodon convention. Direct Messaging between users on the fediverse has mostly been modeled by using ActivityPub addressing following Mastodon conventions on normal `Note` objects. In this case, a 'direct message' would be a message that has no followers addressed and also does not address the special public actor, but just the recipients in the `to` field. It would still be a `Note` and is presented with other `Note`s as a `Status` in the API.
8
9 This is an awkward setup for a few reasons:
10
11 - As DMs generally still follow the usual `Status` conventions, it is easy to accidentally pull somebody into a DM thread by mentioning them. (e.g. "I hate @badguy so much")
12 - It is possible to go from a publicly addressed `Status` to a DM reply, back to public, then to a 'followers only' reply, and so on. This can be become very confusing, as it is unclear which user can see which part of the conversation.
13 - The standard `Status` format of implicit addressing also leads to rather ugly results if you try to display the messages as a chat, because all the recipients are always mentioned by name in the message.
14 - As direct messages are posted with the same api call (and usually same frontend component) as public messages, accidentally making a public message private or vice versa can happen easily. Client bugs can also lead to this, accidentally making private messages public.
15
16 As a measure to improve this situation, the `Conversation` concept and related Pleroma extensions were introduced. While it made it possible to work around a few of the issues, many of the problems remained and it didn't see much adoption because it was too complicated to use correctly.
17
18 ## Chats explained
19 For this reasons, Chats are a new and different entity, both in the API as well as in ActivityPub. A quick overview:
20
21 - Chats are meant to represent an instant message conversation between two actors. For now these are only 1-on-1 conversations, but the other actor can be a group in the future.
22 - Chat messages have the ActivityPub type `ChatMessage`. They are not `Note`s. Servers that don't understand them will just drop them.
23 - The only addressing allowed in `ChatMessage`s is one single ActivityPub actor in the `to` field.
24 - There's always only one Chat between two actors. If you start chatting with someone and later start a 'new' Chat, the old Chat will be continued.
25 - `ChatMessage`s are posted with a different api, making it very hard to accidentally send a message to the wrong person.
26 - `ChatMessage`s don't show up in the existing timelines.
27 - Chats can never go from private to public. They are always private between the two actors.
28
29 ## Caveats
30
31 - Chats are NOT E2E encrypted (yet). Security is still the same as email.
32
33 ## API
34
35 In general, the way to send a `ChatMessage` is to first create a `Chat`, then post a message to that `Chat`. `Group`s will later be supported by making them a sub-type of `Account`.
36
37 This is the overview of using the API. The API is also documented via OpenAPI, so you can view it and play with it by pointing SwaggerUI or a similar OpenAPI tool to `https://yourinstance.tld/api/openapi`.
38
39 ### Creating or getting a chat.
40
41 To create or get an existing Chat for a certain recipient (identified by Account ID)
42 you can call:
43
44 `POST /api/v1/pleroma/chats/by-account-id/{account_id}`
45
46 The account id is the normal FlakeId of the user
47 ```
48 POST /api/v1/pleroma/chats/by-account-id/someflakeid
49 ```
50
51 If you already have the id of a chat, you can also use
52
53 ```
54 GET /api/v1/pleroma/chats/:id
55 ```
56
57 There will only ever be ONE Chat for you and a given recipient, so this call
58 will return the same Chat if you already have one with that user.
59
60 Returned data:
61
62 ```json
63 {
64 "account": {
65 "id": "someflakeid",
66 "username": "somenick",
67 ...
68 },
69 "id" : "1",
70 "unread" : 2,
71 "last_message" : {...} // The last message in that chat
72 }
73 ```
74
75 ### Marking a chat as read
76
77 To set the `unread` count of a chat to 0, call
78
79 `POST /api/v1/pleroma/chats/:id/read`
80
81 Returned data:
82
83 ```json
84 {
85 "account": {
86 "id": "someflakeid",
87 "username": "somenick",
88 ...
89 },
90 "id" : "1",
91 "unread" : 0
92 }
93 ```
94
95
96 ### Getting a list of Chats
97
98 `GET /api/v1/pleroma/chats`
99
100 This will return a list of chats that you have been involved in, sorted by their
101 last update (so new chats will be at the top).
102
103 Returned data:
104
105 ```json
106 [
107 {
108 "account": {
109 "id": "someflakeid",
110 "username": "somenick",
111 ...
112 },
113 "id" : "1",
114 "unread" : 2,
115 "last_message" : {...} // The last message in that chat
116 }
117 ]
118 ```
119
120 The recipient of messages that are sent to this chat is given by their AP ID.
121 The usual pagination options are implemented.
122
123 ### Getting the messages for a Chat
124
125 For a given Chat id, you can get the associated messages with
126
127 `GET /api/v1/pleroma/chats/{id}/messages`
128
129 This will return all messages, sorted by most recent to least recent. The usual
130 pagination options are implemented.
131
132 Returned data:
133
134 ```json
135 [
136 {
137 "account_id": "someflakeid",
138 "chat_id": "1",
139 "content": "Check this out :firefox:",
140 "created_at": "2020-04-21T15:11:46.000Z",
141 "emojis": [
142 {
143 "shortcode": "firefox",
144 "static_url": "https://dontbulling.me/emoji/Firefox.gif",
145 "url": "https://dontbulling.me/emoji/Firefox.gif",
146 "visible_in_picker": false
147 }
148 ],
149 "id": "13"
150 },
151 {
152 "account_id": "someflakeid",
153 "chat_id": "1",
154 "content": "Whats' up?",
155 "created_at": "2020-04-21T15:06:45.000Z",
156 "emojis": [],
157 "id": "12"
158 }
159 ]
160 ```
161
162 ### Posting a chat message
163
164 Posting a chat message for given Chat id works like this:
165
166 `POST /api/v1/pleroma/chats/{id}/messages`
167
168 Parameters:
169 - content: The text content of the message. Optional if media is attached.
170 - media_id: The id of an upload that will be attached to the message.
171
172 Currently, no formatting beyond basic escaping and emoji is implemented.
173
174 Returned data:
175
176 ```json
177 {
178 "account_id": "someflakeid",
179 "chat_id": "1",
180 "content": "Check this out :firefox:",
181 "created_at": "2020-04-21T15:11:46.000Z",
182 "emojis": [
183 {
184 "shortcode": "firefox",
185 "static_url": "https://dontbulling.me/emoji/Firefox.gif",
186 "url": "https://dontbulling.me/emoji/Firefox.gif",
187 "visible_in_picker": false
188 }
189 ],
190 "id": "13"
191 }
192 ```
193
194 ### Deleting a chat message
195
196 Deleting a chat message for given Chat id works like this:
197
198 `DELETE /api/v1/pleroma/chats/{chat_id}/messages/{message_id}`
199
200 Returned data is the deleted message.
201
202 ### Notifications
203
204 There's a new `pleroma:chat_mention` notification, which has this form:
205
206 ```json
207 {
208 "id": "someid",
209 "type": "pleroma:chat_mention",
210 "account": { ... } // User account of the sender,
211 "chat_message": {
212 "chat_id": "1",
213 "id": "10",
214 "content": "Hello",
215 "account_id": "someflakeid"
216 },
217 "created_at": "somedate"
218 }
219 ```