Application Services HTTP API ============================= .. contents:: Table of Contents .. sectnum:: Application Service -> Home Server ---------------------------------- This contains home server APIs which are used by the application service. Registration API ``[Draft]`` ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. NOTE:: - Do we really have to use regex for this? Can't we do this a nicer way? This API registers the application service with its host homeserver to offer its services. Inputs: - Credentials (e.g. some kind of string token) - Namespace[users] - Namespace[room aliases] - URL base to receive inbound comms Output: - The credentials the HS will use to query the AS with in return. (e.g. some kind of string token) Side effects: - The HS will start delivering events to the URL base specified if this 200s. API called when: - The application service wants to register with a brand new home server. Notes: - Namespaces are represented by POSIX extended regular expressions in JSON. They look like:: users: [ "@irc\.freenode\.net/.*", ] :: POST /register Request format { url: "https://my.application.service.com/matrix/", as_token: "some_AS_token", namespaces: { users: [ "@irc\.freenode\.net/.*" ], aliases: [ "#irc\.freenode\.net/.*" ], rooms: [ "!irc\.freenode\.net/.*" ] } } Returns: 200 : Registration accepted. 400 : Namespaces do not conform to regex 401 : Credentials need to be supplied. 403 : AS credentials rejected. 200 OK response format { hs_token: "string" } Unregister API ``[Draft]`` ~~~~~~~~~~~~~~~~~~~~~~~~~~ This API unregisters a previously registered AS from the home server. Inputs: - AS token Output: - None. Side effects: - The HS will stop delivering events to the URL base specified for this AS if this 200s. API called when: - The application service wants to stop receiving all events from the HS. :: POST /unregister Request format { as_token: "string" } Home Server -> Application Service ---------------------------------- This contains application service APIs which are used by the home server. User Query ``[Draft]`` ~~~~~~~~~~~~~~~~~~~~~~ This API is called by the HS to query the existence of a user on the Application Service's namespace. Inputs: - User ID - HS Credentials Output: - Whether the user exists. Side effects: - User is created on the HS by the AS via CS APIs during the processing of this request. API called when: - HS receives an event for an unknown user ID in the AS's namespace, e.g. an invite event to a room. Notes: - When the AS receives this request, if the user exists, it must create the user via the CS API. - It can also set arbitrary information about the user (e.g. display name, join rooms, etc) using the CS API. - When this setup is complete, the AS should respond to the HS request. This means the AS blocks the HS until the user is created. - This is deemed more flexible than alternative methods (e.g. returning a JSON blob with the user's display name and get the HS to provision the user). Retry notes: - The home server cannot respond to the client's request until the response to this API is obtained from the AS. - Recommended that home servers try a few times then time out, returning a 408 Request Timeout to the client. :: GET /users/$user_id?access_token=$hs_token Returns: 200 : User is recognised. 404 : User not found. 401 : Credentials need to be supplied. 403 : HS credentials rejected. 200 OK response format {} Room Alias Query ``[Draft]`` ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ This API is called by the HS to query the existence of a room alias on the Application Service's namespace. Inputs: - Room alias - HS Credentials Output: - The current state events for the room if any. - The message events for the room if any. Side effects: - Room is created on the HS by the AS via CS APIs during the processing of this request. API called when: - HS receives an event to join a room alias in the AS's namespace. Notes: - When the AS receives this request, if the room exists, it must create the room via the CS API. - It can also set arbitrary information about the room (e.g. name, topic, etc) using the CS API. - When this setup is complete, the AS should respond to the HS request. This means the AS blocks the HS until the room is created and configured. - This is deemed more flexible than alternative methods (e.g. returning an initial sync style JSON blob and get the HS to provision the room). It also means that the AS knows the room ID -> alias mapping. Retry notes: - The home server cannot respond to the client's request until the response to this API is obtained from the AS. - Recommended that home servers try a few times then time out, returning a 408 Request Timeout to the client. :: GET /rooms/$room_alias?access_token=$hs_token Returns: 200 : Room is recognised. 404 : Room not found. 401 : Credentials need to be supplied. 403 : HS credentials rejected. 200 OK response format {} Pushing ``[Draft]`` ~~~~~~~~~~~~~~~~~~~ This API is called by the HS when the HS wants to push an event (or batch of events) to the AS. Inputs: - HS Credentials - Event(s) to give to the AS - HS-generated transaction ID Output: - None. Data flows: :: Typical HS ---> AS : Home server sends events with transaction ID T. <--- : AS sends back 200 OK. AS ACK Lost HS ---> AS : Home server sends events with transaction ID T. <-/- : AS 200 OK is lost. HS ---> AS : Home server retries with the same transaction ID of T. <--- : AS sends back 200 OK. If the AS had processed these events already, it can NO-OP this request (and it knows if it is the same events based on the transacton ID). Retry notes: - If the HS fails to pass on the events to the AS, it must retry the request. - Since ASes by definition cannot alter the traffic being passed to it (unlike say, a Policy Server), these requests can be done in parallel to general HS processing; the HS doesn't need to block whilst doing this. - Home servers should use exponential backoff as their retry algorithm. - Home servers MUST NOT alter (e.g. add more) events they were going to send within that transaction ID on retries, as the AS may have already processed the events. Ordering notes: - The events sent to the AS should be linearised, as they are from the event stream. - The home server will need to maintain a queue of transactions to send to the AS. :: PUT /transactions/$transaction_id?access_token=$hs_token Request format { events: [ ... ] } Client-Server v2 API Extensions ------------------------------- Identity assertion ~~~~~~~~~~~~~~~~~~ The client-server API infers the user ID from the ``access_token`` provided in every request. It would be an annoying amount of book-keeping to maintain tokens for every virtual user. It would be preferable if the application service could use the CS API with its own ``as_token`` instead, and specify the virtual user they wish to be acting on behalf of. For real users, this would require additional permissions (see "C-AS Linking"). Inputs: - Application service token (``access_token``) Either: - User ID in the AS namespace to act as. Or: - OAuth2 token of real user (which may end up being an access token) Notes: - This will apply on all aspects of the CS API, except for Account Management. - The ``as_token`` is inserted into ``access_token`` which is usually where the client token is. This is done on purpose to allow application services to reuse client SDKs. :: /path?access_token=$token&user_id=$userid Query Parameters: access_token: The application service token user_id: The desired user ID to act as. /path?access_token=$token&user_token=$token Query Parameters: access_token: The application service token user_token: The token granted to the AS by the real user Timestamp massaging ~~~~~~~~~~~~~~~~~~~ The application service may want to inject events at a certain time (reflecting the time on the network they are tracking e.g. irc, xmpp). Application services need to be able to adjust the ``origin_server_ts`` value to do this. Inputs: - Application service token (``as_token``) - Desired timestamp Notes: - This will only apply when sending events. :: /path?access_token=$token&ts=$timestamp Query Parameters added to the send event APIs only: access_token: The application service token ts: The desired timestamp Server admin style permissions ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The home server needs to give the application service *full control* over its namespace, both for users and for room aliases. This means that the AS should be able to create/edit/delete any room alias in its namespace, as well as create/delete any user in its namespace. This does not require any additional public APIs. ID conventions ``[TODO]`` ------------------------- This concerns the well-defined conventions for mapping 3P network IDs to matrix IDs, which we expect clients to be able to do by themselves. - What do user IDs look like? Butchered URIs? Can all 3P network IDs be reasonably expressed as URIs? (e.g. tel, email, irc, xmpp, ...) - What do room aliases look like? Some cases are clear (e.g. IRC) but others are a lot more fiddly (e.g. email? You don't want to share a room with everyone who has ever sent an email to ``bob@gmail.com``)... Examples -------- .. NOTE:: - User/Alias namespaces are subject to change depending on ID conventions. IRC ~~~ Pre-conditions: - Server admin stores the AS token "T_a" on the home server. - Home server has a token "T_h". - Home server has the domain "hsdomain.com" 1. Application service registration :: AS -> HS: Registers itself with the home server POST /register { url: "https://someapp.com/matrix", as_token: "T_a", namespaces: { users: [ "@irc\.freenode\.net/.*" ], aliases: [ "#irc\.freenode\.net/.*" ], rooms: [ "!irc\.freenode\.net/.*" ] } } Returns 200 OK: { hs_token: "T_h" } 2. IRC user "Bob" says "hello?" on "#matrix" at timestamp 1421416883133: :: - AS stores message as potential scrollback. - Nothing happens as no Matrix users are in the room. 3. Matrix user "@alice:hsdomain.com" wants to join "#matrix": :: User -> HS: Request to join "#irc.freenode.net/#matrix:hsdomain.com" HS -> AS: Room Query "#irc.freenode.net/#matrix:hsdomain.com" GET /rooms/%23irc.freenode.net%2F%23matrix%3Ahsdomain.com?access_token=T_h [Starts blocking] AS -> HS: Creates room. Gets room ID "!aasaasasa:matrix.org". AS -> HS: Sets room name to "#matrix". AS -> HS: Sends message as ""@irc.freenode.net/Bob:hsdomain.com" PUT /rooms/%21irc.freenode.net%2F%23matrix%3Ahsdomain.com/send/m.room.message ?access_token=T_a &user_id=%40irc.freenode.net%2FBob%3Ahsdomain.com &ts=1421416883133 { body: "hello?" msgtype: "m.text" } HS -> AS: User Query "@irc.freenode.net/Bob:hsdomain.com" GET /users/%40irc.freenode.net%2FBob%3Ahsdomain.com?access_token=T_h [Starts blocking] AS -> HS: Creates user using CS API extension. AS -> HS: Set user display name to "Bob". [Finishes blocking] [Finished blocking] - HS sends room information back to client. 4. @alice:hsdomain.com says "hi!" in this room: :: User -> HS: Send message "hi!" in room !irc.freenode.net/#matrix:hsdomain.com - HS sends message. - HS sees the room ID is in the AS namespace and pushes it to the AS. HS -> AS: Push event PUT /transactions/1?access_token=T_h { events: [ { content: { body: "hi!", msgtype: "m.text" }, origin_server_ts: , user_id: "@alice:hsdomain.com", room_id: "!irc.freenode.net/#matrix:hsdomain.com", type: "m.room.message" } ] } - AS passes this through to IRC. 5. IRC user "Bob" says "what's up?" on "#matrix" at timestamp 1421418084816: :: IRC -> AS: "what's up?" AS -> HS: Send message via CS API extension PUT /rooms/%21irc.freenode.net%2F%23matrix%3Ahsdomain.com/send/m.room.message ?access_token=T_a &user_id=%40irc.freenode.net%2FBob%3Ahsdomain.com &ts=1421418084816 { body: "what's up?" msgtype: "m.text" } - HS modifies the user_id and origin_server_ts on the event and sends it.