You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
423 lines
20 KiB
Markdown
423 lines
20 KiB
Markdown
---
|
|
title: "Application Service API"
|
|
weight: 30
|
|
type: docs
|
|
---
|
|
|
|
The Matrix client-server API and server-server APIs provide the means to
|
|
implement a consistent self-contained federated messaging fabric.
|
|
However, they provide limited means of implementing custom server-side
|
|
behaviour in Matrix (e.g. gateways, filters, extensible hooks etc). The
|
|
Application Service API (AS API) defines a standard API to allow such
|
|
extensible functionality to be implemented irrespective of the
|
|
underlying homeserver implementation.
|
|
|
|
## Application Services
|
|
|
|
Application services are passive and can only observe events from
|
|
homeserver. They can inject events into rooms they are participating in.
|
|
They cannot prevent events from being sent, nor can they modify the
|
|
content of the event being sent. In order to observe events from a
|
|
homeserver, the homeserver needs to be configured to pass certain types
|
|
of traffic to the application service. This is achieved by manually
|
|
configuring the homeserver with information about the application
|
|
service.
|
|
|
|
### Registration
|
|
|
|
{{% boxes/note %}}
|
|
Previously, application services could register with a homeserver via
|
|
HTTP APIs. This was removed as it was seen as a security risk. A
|
|
compromised application service could re-register for a global `*` regex
|
|
and sniff *all* traffic on the homeserver. To protect against this,
|
|
application services now have to register via configuration files which
|
|
are linked to the homeserver configuration file. The addition of
|
|
configuration files allows homeserver admins to sanity check the
|
|
registration for suspicious regex strings.
|
|
{{% /boxes/note %}}
|
|
|
|
Application services register "namespaces" of user IDs, room aliases and
|
|
room IDs. These namespaces are represented as regular expressions. An
|
|
application service is said to be "interested" in a given event if one
|
|
of the IDs in the event match the regular expression provided by the
|
|
application service, such as the room having an alias or ID in the
|
|
relevant namespaces. Similarly, the application service is said to be
|
|
interested in a given event if one of the application service's
|
|
namespaced users is the target of the event, or is a joined member of
|
|
the room where the event occurred.
|
|
|
|
An application service can also state whether they should be the only
|
|
ones who can manage a specified namespace. This is referred to as an
|
|
"exclusive" namespace. An exclusive namespace prevents humans and other
|
|
application services from creating/deleting entities in that namespace.
|
|
Typically, exclusive namespaces are used when the rooms represent real
|
|
rooms on another service (e.g. IRC). Non-exclusive namespaces are used
|
|
when the application service is merely augmenting the room itself (e.g.
|
|
providing logging or searching facilities). Namespaces are represented
|
|
by POSIX extended regular expressions and look like:
|
|
|
|
users:
|
|
- exclusive: true
|
|
regex: "@_irc_bridge_.*"
|
|
|
|
Application services may define the following namespaces (with none
|
|
being explicitly required):
|
|
|
|
| Name | Description |
|
|
|----------|------------------------------------------------------------|
|
|
| users | Events which are sent from certain users. |
|
|
| aliases | Events which are sent in rooms with certain room aliases. |
|
|
| rooms | Events which are sent in rooms with certain room IDs. |
|
|
|
|
Each individual namespace MUST declare the following fields:
|
|
|
|
| Name | Description |
|
|
|------------|------------------------------------------------------------------------------------------------------------------------------------|
|
|
| exclusive | **Required** A true or false value stating whether this application service has exclusive access to events within this namespace. |
|
|
| regex | **Required** A regular expression defining which values this namespace includes. |
|
|
|
|
Exclusive user and alias namespaces should begin with an underscore
|
|
after the sigil to avoid collisions with other users on the homeserver.
|
|
Application services should additionally attempt to identify the service
|
|
they represent in the reserved namespace. For example, `@_irc_.*` would
|
|
be a good namespace to register for an application service which deals
|
|
with IRC.
|
|
|
|
The registration is represented by a series of key-value pairs, which
|
|
this specification will present as YAML. See below for the possible
|
|
options along with their explanation:
|
|
|
|
|
|
| Name | Description |
|
|
|-------------------|-----------------------------------------------------------------------------------------------------------------------------------------------|
|
|
| id | **Required** A unique, user-defined ID of the application service which will never change. |
|
|
| url | **Required** The URL for the application service. May include a path after the domain name. Optionally set to null if no traffic is required. |
|
|
| as_token | **Required** A unique token for application services to use to authenticate requests to Homeservers. |
|
|
| hs_token | **Required** A unique token for Homeservers to use to authenticate requests to application services. |
|
|
| sender_localpart | **Required** The localpart of the user associated with the application service. |
|
|
| namespaces | **Required** A list of `users`, `aliases` and `rooms` namespaces that the application service controls. |
|
|
| rate_limited | Whether requests from masqueraded users are rate-limited. The sender is excluded. |
|
|
| protocols | The external protocols which the application service provides (e.g. IRC). |
|
|
|
|
An example registration file for an IRC-bridging application service is
|
|
below:
|
|
|
|
id: "IRC Bridge"
|
|
url: "http://127.0.0.1:1234"
|
|
as_token: "30c05ae90a248a4188e620216fa72e349803310ec83e2a77b34fe90be6081f46"
|
|
hs_token: "312df522183efd404ec1cd22d2ffa4bbc76a8c1ccf541dd692eef281356bb74e"
|
|
sender_localpart: "_irc_bot" # Will result in @_irc_bot:example.org
|
|
namespaces:
|
|
users:
|
|
- exclusive: true
|
|
regex: "@_irc_bridge_.*"
|
|
aliases:
|
|
- exclusive: false
|
|
regex: "#_irc_bridge_.*"
|
|
rooms: []
|
|
|
|
{{% boxes/warning %}}
|
|
If the homeserver in question has multiple application services, each
|
|
`as_token` and `id` MUST be unique per application service as these are
|
|
used to identify the application service. The homeserver MUST enforce
|
|
this.
|
|
{{% /boxes/warning %}}
|
|
|
|
### Homeserver -> Application Service API
|
|
|
|
#### Authorization
|
|
|
|
Homeservers MUST include a query parameter named `access_token`
|
|
containing the `hs_token` from the application service's registration
|
|
when making requests to the application service. Application services
|
|
MUST verify the provided `access_token` matches their known `hs_token`,
|
|
failing the request with an `M_FORBIDDEN` error if it does not match.
|
|
|
|
#### Legacy routes
|
|
|
|
Previous drafts of the application service specification had a mix of
|
|
endpoints that have been used in the wild for a significant amount of
|
|
time. The application service specification now defines a version on all
|
|
endpoints to be more compatible with the rest of the Matrix
|
|
specification and the future.
|
|
|
|
Homeservers should attempt to use the specified endpoints first when
|
|
communicating with application services. However, if the application
|
|
service receives an HTTP status code that does not indicate success
|
|
(i.e.: 404, 500, 501, etc) then the homeserver should fall back to the
|
|
older endpoints for the application service.
|
|
|
|
The older endpoints have the exact same request body and response
|
|
format, they just belong at a different path. The equivalent path for
|
|
each is as follows:
|
|
|
|
- `/_matrix/app/v1/transactions/{txnId}` should fall back to
|
|
`/transactions/{txnId}`
|
|
- `/_matrix/app/v1/users/{userId}` should fall back to
|
|
`/users/{userId}`
|
|
- `/_matrix/app/v1/rooms/{roomAlias}` should fall back to
|
|
`/rooms/{roomAlias}`
|
|
- `/_matrix/app/v1/thirdparty/protocol/{protocol}` should fall back to
|
|
`/_matrix/app/unstable/thirdparty/protocol/{protocol}`
|
|
- `/_matrix/app/v1/thirdparty/user/{user}` should fall back to
|
|
`/_matrix/app/unstable/thirdparty/user/{user}`
|
|
- `/_matrix/app/v1/thirdparty/location/{location}` should fall back to
|
|
`/_matrix/app/unstable/thirdparty/location/{location}`
|
|
- `/_matrix/app/v1/thirdparty/user` should fall back to
|
|
`/_matrix/app/unstable/thirdparty/user`
|
|
- `/_matrix/app/v1/thirdparty/location` should fall back to
|
|
`/_matrix/app/unstable/thirdparty/location`
|
|
|
|
Homeservers should periodically try again for the newer endpoints
|
|
because the application service may have been updated.
|
|
|
|
#### Pushing events
|
|
|
|
The application service API provides a transaction API for sending a
|
|
list of events. Each list of events includes a transaction ID, which
|
|
works as follows:
|
|
|
|
```
|
|
Typical
|
|
HS ---> AS : Homeserver sends events with transaction ID T.
|
|
<--- : Application Service sends back 200 OK.
|
|
```
|
|
|
|
```
|
|
AS ACK Lost
|
|
HS ---> AS : Homeserver sends events with transaction ID T.
|
|
<-/- : AS 200 OK is lost.
|
|
HS ---> AS : Homeserver retries with the same transaction ID of T.
|
|
<--- : Application Service 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 transaction ID).
|
|
```
|
|
|
|
The events sent to the application service should be linearised, as if
|
|
they were from the event stream. The homeserver MUST maintain a queue of
|
|
transactions to send to the application service. If the application
|
|
service cannot be reached, the homeserver SHOULD backoff exponentially
|
|
until the application service is reachable again. As application
|
|
services cannot *modify* the events in any way, these requests can be
|
|
made without blocking other aspects of the homeserver. Homeservers MUST
|
|
NOT alter (e.g. add more) events they were going to send within that
|
|
transaction ID on retries, as the application service may have already
|
|
processed the events.
|
|
|
|
{{% http-api spec="application-service" api="transactions" %}}
|
|
|
|
#### Querying
|
|
|
|
The application service API includes two querying APIs: for room aliases
|
|
and for user IDs. The application service SHOULD create the queried
|
|
entity if it desires. During this process, the application service is
|
|
blocking the homeserver until the entity is created and configured. If
|
|
the homeserver does not receive a response to this request, the
|
|
homeserver should retry several times before timing out. This should
|
|
result in an HTTP status 408 "Request Timeout" on the client which
|
|
initiated this request (e.g. to join a room alias).
|
|
|
|
{{% boxes/rationale %}}
|
|
Blocking the homeserver and expecting the application service to create
|
|
the entity using the client-server API is simpler and more flexible than
|
|
alternative methods such as returning an initial sync style JSON blob
|
|
and get the HS to provision the room/user. This also meant that there
|
|
didn't need to be a "backchannel" to inform the application service
|
|
about information about the entity such as room ID to room alias
|
|
mappings.
|
|
{{% /boxes/rationale %}}
|
|
|
|
{{% http-api spec="application-service" api="query_user" %}}
|
|
|
|
{{% http-api spec="application-service" api="query_room" %}}
|
|
|
|
#### Third party networks
|
|
|
|
Application services may declare which protocols they support via their
|
|
registration configuration for the homeserver. These networks are
|
|
generally for third party services such as IRC that the application
|
|
service is managing. Application services may populate a Matrix room
|
|
directory for their registered protocols, as defined in the
|
|
Client-Server API Extensions.
|
|
|
|
Each protocol may have several "locations" (also known as "third party
|
|
locations" or "3PLs"). A location within a protocol is a place in the
|
|
third party network, such as an IRC channel. Users of the third party
|
|
network may also be represented by the application service.
|
|
|
|
Locations and users can be searched by fields defined by the application
|
|
service, such as by display name or other attribute. When clients
|
|
request the homeserver to search in a particular "network" (protocol),
|
|
the search fields will be passed along to the application service for
|
|
filtering.
|
|
|
|
{{% http-api spec="application-service" api="protocols" %}}
|
|
|
|
### Client-Server API Extensions
|
|
|
|
Application services can use a more powerful version of the
|
|
client-server API by identifying itself as an application service to the
|
|
homeserver.
|
|
|
|
Endpoints defined in this section MUST be supported by homeservers in
|
|
the client-server API as accessible only by application services.
|
|
|
|
#### Identity assertion
|
|
|
|
The client-server API infers the user ID from the `access_token`
|
|
provided in every request. To avoid the application service from having
|
|
to keep track of each user's access token, the application service
|
|
should identify itself to the Client-Server API by providing its
|
|
`as_token` for the `access_token` alongside the user the application
|
|
service would like to masquerade as.
|
|
|
|
Inputs:
|
|
- Application service token (`as_token`)
|
|
- User ID in the AS namespace to act as.
|
|
|
|
Notes:
|
|
- This applies to all aspects of the Client-Server API, except for
|
|
Account Management.
|
|
- The `as_token` is inserted into `access_token` which is usually
|
|
where the client token is, such as via the query string or
|
|
`Authorization` header. This is done on purpose to allow application
|
|
services to reuse client SDKs.
|
|
- The `access_token` should be supplied through the `Authorization`
|
|
header where possible to prevent the token appearing in HTTP request
|
|
logs by accident.
|
|
|
|
The application service may specify the virtual user to act as through
|
|
use of a `user_id` query string parameter on the request. The user
|
|
specified in the query string must be covered by one of the application
|
|
service's `user` namespaces. If the parameter is missing, the homeserver
|
|
is to assume the application service intends to act as the user implied
|
|
by the `sender_localpart` property of the registration.
|
|
|
|
An example request would be:
|
|
|
|
GET /_matrix/client/v3/account/whoami?user_id=@_irc_user:example.org
|
|
Authorization: Bearer YourApplicationServiceTokenHere
|
|
|
|
#### Timestamp massaging
|
|
|
|
{{% added-in v="1.3" %}}
|
|
|
|
Application services can alter the timestamp associated with an event, allowing
|
|
the application service to better represent the "real" time an event was sent
|
|
at. While this doesn't affect the server-side ordering of the event, it can allow
|
|
an application service to better represent when an event would have been sent/received
|
|
at, such as in the case of bridges where the remote network might have a slight
|
|
delay and the application service wishes to bridge the proper time onto the message.
|
|
|
|
When authenticating requests as an application service, the caller can append a `ts`
|
|
query string argument to change the `origin_server_ts` of the resulting event. Attempting
|
|
to set the timestamp to anything other than what is accepted by `origin_server_ts` should
|
|
be rejected by the server as a bad request.
|
|
|
|
When not present, the server's behaviour is unchanged: the local system time of the server
|
|
will be used to provide a timestamp, representing "now".
|
|
|
|
The `ts` query string argument is only valid on the following endpoints:
|
|
|
|
* [`PUT /rooms/{roomId}/send/{eventType}/{txnId}`](/client-server-api/#put_matrixclientv3roomsroomidsendeventtypetxnid)
|
|
* [`PUT /rooms/{roomId}/state/{eventType}/{stateKey}`](/client-server-api/#put_matrixclientv3roomsroomidstateeventtypestatekey)
|
|
|
|
Other endpoints, such as `/kick`, do not support `ts`: instead, callers can use the
|
|
`PUT /state` endpoint to mimic the behaviour of the other APIs.
|
|
|
|
{{% boxes/warning %}}
|
|
Changing the time of an event does not change the server-side (DAG) ordering for the
|
|
event. The event will still be appended at the tip of the DAG as though the timestamp
|
|
was set to "now". Future MSCs, like [MSC2716](https://github.com/matrix-org/matrix-spec-proposals/pull/2716),
|
|
are expected to provide functionality which can allow DAG order manipulation (for history
|
|
imports and similar behaviour).
|
|
{{% /boxes/warning %}}
|
|
|
|
#### Server admin style permissions
|
|
|
|
The homeserver 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 manage any users and room alias in its namespace. No additional API
|
|
changes need to be made in order for control of room aliases to be
|
|
granted to the AS.
|
|
|
|
Creation of users needs API changes in order to:
|
|
|
|
- Work around captchas.
|
|
- Have a 'passwordless' user.
|
|
|
|
This involves bypassing the registration flows entirely. This is
|
|
achieved by including the `as_token` on a `/register` request, along
|
|
with a login type of `m.login.application_service` to set the desired
|
|
user ID without a password.
|
|
|
|
POST /_matrix/client/v3/register
|
|
Authorization: Bearer YourApplicationServiceTokenHere
|
|
|
|
Content:
|
|
{
|
|
type: "m.login.application_service",
|
|
username: "_irc_example"
|
|
}
|
|
|
|
Similarly, logging in as users needs API changes in order to allow the AS to
|
|
log in without needing the user's password. This is achieved by including the
|
|
`as_token` on a `/login` request, along with a login type of
|
|
`m.login.application_service`:
|
|
|
|
{{% added-in v="1.2" %}}
|
|
|
|
POST /_matrix/client/v3/login
|
|
Authorization: Bearer YourApplicationServiceTokenHere
|
|
|
|
Content:
|
|
{
|
|
type: "m.login.application_service",
|
|
"identifier": {
|
|
"type": "m.id.user",
|
|
"user": "_irc_example"
|
|
}
|
|
}
|
|
|
|
Application services which attempt to create users or aliases *outside*
|
|
of their defined namespaces, or log in as users outside of their defined
|
|
namespaces will receive an error code `M_EXCLUSIVE`.
|
|
Similarly, normal users who attempt to create users or aliases *inside*
|
|
an application service-defined namespace will receive the same
|
|
`M_EXCLUSIVE` error code, but only if the application service has
|
|
defined the namespace as `exclusive`.
|
|
|
|
#### Using `/sync` and `/events`
|
|
|
|
Application services wishing to use `/sync` or `/events` from the
|
|
Client-Server API MUST do so with a virtual user (provide a `user_id`
|
|
via the query string). It is expected that the application service use
|
|
the transactions pushed to it to handle events rather than syncing with
|
|
the user implied by `sender_localpart`.
|
|
|
|
#### Application service room directories
|
|
|
|
Application services can maintain their own room directories for their
|
|
defined third party protocols. These room directories may be accessed by
|
|
clients through additional parameters on the `/publicRooms`
|
|
client-server endpoint.
|
|
|
|
{{% http-api spec="client-server" api="appservice_room_directory" %}}
|
|
|
|
### Referencing messages from a third party network
|
|
|
|
Application services should include an `external_url` in the `content`
|
|
of events it emits to indicate where the message came from. This
|
|
typically applies to application services that bridge other networks
|
|
into Matrix, such as IRC, where an HTTP URL may be available to
|
|
reference.
|
|
|
|
Clients should provide users with a way to access the `external_url` if
|
|
it is present. Clients should additionally ensure the URL has a scheme
|
|
of `https` or `http` before making use of it.
|
|
|
|
The presence of an `external_url` on an event does not necessarily mean
|
|
the event was sent from an application service. Clients should be wary
|
|
of the URL contained within, as it may not be a legitimate reference to
|
|
the event's source.
|