From e62f8542a1933ba71dfd236741ad3afc76b89f22 Mon Sep 17 00:00:00 2001 From: lain Date: Mon, 27 Apr 2020 13:48:09 +0200 Subject: [PATCH] Docs: Add chat motivation and api description. --- docs/API/chats.md | 197 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 197 insertions(+) create mode 100644 docs/API/chats.md diff --git a/docs/API/chats.md b/docs/API/chats.md new file mode 100644 index 000000000..39f493b47 --- /dev/null +++ b/docs/API/chats.md @@ -0,0 +1,197 @@ +# Chats + +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. + +## Why Chats? + +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. + +This is an awkward setup for a few reasons: + +- 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") +- 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. +- 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. +- 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. + +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. + +## Chats explained +For this reasons, Chats are a new and different entity, both in the API as well as in ActivityPub. A quick overview: + +- 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. +- Chat messages have the ActivityPub type `ChatMessage`. They are not `Note`s. Servers that don't understand them will just drop them. +- The only addressing allowed in `ChatMessage`s is one single ActivityPub actor in the `to` field. +- 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. +- `ChatMessage`s are posted with a different api, making it very hard to accidentally send a message to the wrong person. +- `ChatMessage`s don't show up in the existing timelines. +- Chats can never go from private to public. They are always private between the two actors. + +## Caveats + +- Chats are NOT E2E encrypted (yet). Security is still the same as email. + +## API + +In general, the way to send a `ChatMessage` is to first create a `Chat`, then post a message to that `Chat`. The actors in the API are generally given by their ActivityPub id to make it easier to support later `Group` scenarios. + +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`. + +### Creating or getting a chat. + +To create or get an existing Chat for a certain recipient (identified by AP ID) +you can call: + +`POST /api/v1/pleroma/chats/by-ap-id/{ap_id}` + +The ap_id of the recipients needs to be www-form encoded, so + +``` +https://originalpatchou.li/user/lambda +``` + +would become + +``` +https%3A%2F%2Foriginalpatchou.li%2Fuser%2Flambda +``` + +The full call would then be + +``` +POST /api/v1/pleroma/chats/by-ap-id/https%3A%2F%2Foriginalpatchou.li%2Fuser%2Flambda +``` + +There will only ever be ONE Chat for you and a given recipient, so this call +will return the same Chat if you already have one with that user. + +Returned data: + +```json +{ + "recipient" : "https://dontbulling.me/users/lain", + "recipient_account": { + "id": "someflakeid", + "username": "somenick", + ... + }, + "id" : "1", + "unread" : 2 +} +``` + +### Getting a list of Chats + +`GET /api/v1/pleroma/chats` + +This will return a list of chats that you have been involved in, sorted by their +last update (so new chats will be at the top). + +Returned data: + +```json +[ + { + "recipient" : "https://dontbulling.me/users/lain", + "recipient_account": { + "id": "someflakeid", + "username": "somenick", + ... + }, + "id" : "1", + "unread" : 2 + } +] +``` + +The recipient of messages that are sent to this chat is given by their AP ID. +The usual pagination options are implemented. + +### Getting the messages for a Chat + +For a given Chat id, you can get the associated messages with + +`GET /api/v1/pleroma/chats/{id}/messages` + +This will return all messages, sorted by most recent to least recent. The usual +pagination options are implemented + +Returned data: + +```json +[ + { + "actor": "https://dontbulling.me/users/lain", + "chat_id": "1", + "content": "Check this out :firefox:", + "created_at": "2020-04-21T15:11:46.000Z", + "emojis": [ + { + "shortcode": "firefox", + "static_url": "https://dontbulling.me/emoji/Firefox.gif", + "url": "https://dontbulling.me/emoji/Firefox.gif", + "visible_in_picker": false + } + ], + "id": "13" + }, + { + "actor": "https://dontbulling.me/users/lain", + "chat_id": "1", + "content": "Whats' up?", + "created_at": "2020-04-21T15:06:45.000Z", + "emojis": [], + "id": "12" + } +] +``` + +### Posting a chat message + +Posting a chat message for given Chat id works like this: + +`POST /api/v1/pleroma/chats/{id}/messages` + +Parameters: +- content: The text content of the message + +Currently, no formatting beyond basic escaping and emoji is implemented, as well as no +attachments. This will most probably change. + +Returned data: + +```json +{ + "actor": "https://dontbulling.me/users/lain", + "chat_id": "1", + "content": "Check this out :firefox:", + "created_at": "2020-04-21T15:11:46.000Z", + "emojis": [ + { + "shortcode": "firefox", + "static_url": "https://dontbulling.me/emoji/Firefox.gif", + "url": "https://dontbulling.me/emoji/Firefox.gif", + "visible_in_picker": false + } + ], + "id": "13" +} +``` + +### Notifications + +There's a new `pleroma:chat_mention` notification, which has this form: + +```json +{ + "id": "someid", + "type": "pleroma:chat_mention", + "account": { ... } // User account of the sender, + "chat_message": { + "chat_id": "1", + "id": "10", + "content": "Hello", + "actor": "https://dontbulling.me/users/lain" + }, + "created_at": "somedate" +} +```