33 KiB
Push Notifications
+--------------------+ +-------------------+
Matrix HTTP | | | |
Notification Protocol | App Developer | | Device Vendor |
| | | |
+-------------------+ | +----------------+ | | +---------------+ |
| | | | | | | | | |
| Matrix homeserver +-----> Push Gateway +------> Push Provider | |
| | | | | | | | | |
+-^-----------------+ | +----------------+ | | +----+----------+ |
| | | | | |
Matrix | | | | | |
Client/Server API + | | | | |
| | +--------------------+ +-------------------+
| +--+-+ |
| | <-------------------------------------------+
+---+ |
| | Provider Push Protocol
+----+
Mobile Device or Client
This module adds support for push notifications. Homeservers send notifications of events to user-configured HTTP endpoints. Users may also configure a number of rules that determine which events generate notifications. These are all stored and managed by the user's homeserver. This allows user-specific push settings to be reused between client applications.
The above diagram shows the flow of push notifications being sent to a handset where push notifications are submitted via the handset vendor, such as Apple's APNS or Google's GCM. This happens as follows:
- The client app signs in to a homeserver.
- The client app registers with its vendor's Push Provider and obtains a routing token of some kind.
- The mobile app uses the Client/Server API to add a 'pusher', providing the URL of a specific Push Gateway which is configured for that application. It also provides the routing token it has acquired from the Push Provider.
- The homeserver starts sending HTTP requests to the Push Gateway using the supplied URL. The Push Gateway relays this notification to the Push Provider, passing the routing token along with any necessary private credentials the provider requires to send push notifications.
- The Push Provider sends the notification to the device.
Definitions for terms used in this section are below:
- Push Provider
-
A push provider is a service managed by the device vendor which can send notifications directly to the device. Google Cloud Messaging (GCM) and Apple Push Notification Service (APNS) are two examples of push providers.
- Push Gateway
-
A push gateway is a server that receives HTTP event notifications from homeservers and passes them on to a different protocol such as APNS for iOS devices or GCM for Android devices. Clients inform the homeserver which Push Gateway to send notifications to when it sets up a Pusher.
- Pusher
-
A pusher is a worker on the homeserver that manages the sending of HTTP notifications for a user. A user can have multiple pushers: one per device.
- Push Rule
-
A push rule is a single rule that states under what conditions an event should be passed onto a push gateway and how the notification should be presented. These rules are stored on the user's homeserver. They are manually configured by the user, who can create and view them via the Client/Server API.
- Push Ruleset
-
A push ruleset scopes a set of rules according to some criteria. For example, some rules may only be applied for messages from a particular sender, a particular room, or by default. The push ruleset contains the entire set of scopes and rules.
Push Rules
A push rule is a single rule that states under what conditions an
event should be passed onto a push gateway and how the notification
should be presented. There are different "kinds" of push rules and each
rule has an associated priority. Every push rule MUST have a kind and
rule_id. The rule_id is a unique string within the kind of rule and
its' scope: rule_ids do not need to be unique between rules of the
same kind on different devices. Rules may have extra keys depending on
the value of kind.
The different kinds of rule, in the order that they are checked, are:
-
Override rules (
override). The highest priority rules are user-configured overrides. -
Content-specific rules (
content). These configure behaviour for messages that match certain patterns. Content rules take one parameter:pattern, that gives the glob-style pattern to match against. The match is performed case-insensitively, and must match any substring of thecontent.bodyproperty which starts and ends at a word boundary. A word boundary is defined as the start or end of the value, or any character not in the sets[A-Z],[a-z],[0-9]or_.The exact meaning of "case insensitive" is defined by the implementation of the homeserver. -
Room-specific rules (
room). These rules change the behaviour of all messages for a given room. Therule_idof a room rule is always the ID of the room that it affects. -
Sender-specific rules (
sender). These rules configure notification behaviour for messages from a specific Matrix user ID. Therule_idof Sender rules is always the Matrix user ID of the user whose messages they'd apply to. -
Underride rules (
underride). These are identical tooverriderules, but have a lower priority thancontent,roomandsenderrules.
Rules with the same kind can specify an ordering priority. This
determines which rule is selected in the event of multiple matches. For
example, a rule matching "tea" and a separate rule matching "time" would
both match the sentence "It's time for tea". The ordering of the rules
would then resolve the tiebreak to determine which rule is executed.
Only actions for highest priority rule will be sent to the Push
Gateway.
Each rule can be enabled or disabled. Disabled rules never match. If no rules match an event, the homeserver MUST NOT notify the Push Gateway for that event. Homeservers MUST NOT notify the Push Gateway for events that the user has sent themselves.
Actions
All rules have an associated list of actions. An action affects if and
how a notification is delivered for a matching event. The following
actions are defined:
notify-
This causes each matching event to generate a notification.
set_tweak-
Sets an entry in the
tweaksdictionary key that is sent in the notification request to the Push Gateway. This takes the form of a dictionary with aset_tweakkey whose value is the name of the tweak to set. It may also have avaluekey which is the value to which it should be set.The following tweaks are defined:
sound-
A string representing the sound to be played when this notification arrives. A value of
defaultmeans to play a default sound. A device may choose to alert the user by some other means if appropriate, eg. vibration. highlight-
A boolean representing whether or not this message should be highlighted in the UI. This will normally take the form of presenting the message in a different colour and/or style. The UI might also be adjusted to draw particular attention to the room in which the event occurred. If a
highlighttweak is given with no value, its value is defined to betrue. If no highlight tweak is given at all then the value ofhighlightis defined to be false.
Tweaks are passed transparently through the homeserver so client applications and Push Gateways may agree on additional tweaks. For example, a tweak may be added to specify how to flash the notification light on a mobile device.
Actions that have no parameters are represented as a string. Otherwise,
they are represented as a dictionary with a key equal to their name and
other keys as their parameters, e.g.
{ "set_tweak": "sound", "value": "default" }.
{{% boxes/note %}}
Older versions of the Matrix specification included the dont_notify and
coalesce actions. These should both be considered no-ops (ignored, not
rejected) if received from a client.
{{% /boxes/note %}}
Conditions
override and underride rules MAY have a list of 'conditions'. All
conditions must hold true for an event in order for the rule to match. A
rule with no conditions always matches.
Unrecognised conditions MUST NOT match any events, effectively making the push rule disabled.
room, sender and content rules do not have conditions in the same
way, but instead have predefined conditions. In the cases of room and
sender rules, the rule_id of the rule determines its behaviour.
The following conditions are defined:
event_match
This is a glob pattern match on a property of the event. Parameters:
-
key: The dot-separated path of the property of the event to match, e.g.content.body. -
pattern: The glob-style pattern to match against.
The match is performed case-insensitively, and must match the entire value of
the event property given by key (though see below regarding content.body). The
exact meaning of "case insensitive" is defined by the implementation of the
homeserver.
If the property specified by key is completely absent from the event, or does
not have a string value, then the condition will not match, even if pattern
is *.
{{% boxes/note %}}
For example, if key is content.topic, and pattern is lunc?*, then
the following event will match:
{
"content": {
"topic": "Lunch plans",
},
"event_id": "$143273582443PhrSn:example.org",
"room_id": "!636q39766251:example.com",
"sender": "@example:example.org",
"state_key": "",
"type": "m.room.topic"
}
Other topic values which will match are:
"LUNCH"(case-insensitive;*may match zero characters)
The following topic values will NOT match:
" lunch"(note leading space)"lunc"(?must match a character)null(not a string) {{% /boxes/note %}}
As a special case, if key is content.body, then pattern must instead
match any substring of the value of the property which starts and ends at a
word boundary. A word boundary is defined as the start or end of the value, or
any character not in the sets [A-Z], [a-z], [0-9] or _.
{{% boxes/note %}}
For example, if key is content.body and pattern is ex*ple, the
following event will match:
{
"content": {
"body": "An example event."
},
"event_id": "$143273976499sgjks:example.org",
"room_id": "!636q39766251:example.com",
"sender": "@example:example.org",
"type": "m.room.message"
}
Other body values which will match are:
"exple"(the pattern can match at the start and end of the body.)"An exciting triple-whammy"(the pattern can span multiple words, and-acts as a word separator.) {{% /boxes/note %}}
{{% boxes/warning %}}
Note that there is no implicit condition for state_key. In other words, push
rules which should match only state events must include an explicit condition
for state_key.
For an example of this, see the default rule
.m.rule.tombstone below.
{{% /boxes/warning %}}
event_property_is
This is an exact value match on a property of the event. Parameters:
-
key: The dot-separated path of the property of the event to match, e.g.content.body. -
value: The value to match against.
The match is performed exactly and only supports non-compound canonical JSON
values: strings, integers in the range of [-(2**53)+1, (2**53)-1], booleans, and
null.
If the property specified by key is completely absent from the event, or does
not have a string, integer, boolean, or null value, then the condition will not
match.
{{% boxes/note %}}
For example, if key is content.m\.federate, and value is true, then
the following event will match:
{
"content": {
"creator": "@example:example.org",
"m.federate": true,
"predecessor": {
"event_id": "$something:example.org",
"room_id": "!oldroom:example.org"
},
"room_version": "1"
},
"event_id": "$143273582443PhrSn:example.org",
"room_id": "!636q39766251:example.com",
"sender": "@example:example.org",
"state_key": "",
"type": "m.room.create"
}
The following m.federate values will NOT match:
"true"(note the string value)1(do not cast types) {{% /boxes/note %}}
event_property_contains
This matches if an array property of an event exactly contains a value. Parameters:
-
key: The dot-separated path of the property of the event to match, e.g.content.body. -
value: The value to match against.
The array values are matched exactly and only supports non-compound canonical JSON
values: strings, integers in the range of [-(2**53)+1, (2**53)-1], booleans,
and null. Array values not of those types are ignored.
If the property specified by key is completely absent from the event, or is not
an array, then the condition will not match.
{{% boxes/note %}}
For example, if key is content.alt_aliases, and value is "#myroom:example.com",
then the following event will match:
{
"content": {
"alias": "#somewhere:localhost",
"alt_aliases": [
"#somewhere:example.org",
"#myroom:example.com"
]
},
"event_id": "$143273582443PhrSn:example.org",
"origin_server_ts": 1432735824653,
"room_id": "!jEsUZKDJdhlrceRyVU:example.org",
"sender": "@example:example.org",
"state_key": "",
"type": "m.room.canonical_alias",
"unsigned": {
"age": 1234
}
}
The following alt_aliases values will NOT match:
":example.com"(partial values do not match) {{% /boxes/note %}}
contains_display_name
This matches messages where content.body contains the owner's display name in
that room. This is a separate condition because display names may change and as such
it would be hard to maintain a rule that matched the user's display name. This
condition has no parameters.
room_member_count
This matches the current number of members in the room. Parameters:
is: A decimal integer optionally prefixed by one of,==,<,>,>=or<=. A prefix of<matches rooms where the member count is strictly less than the given number and so forth. If no prefix is present, this parameter defaults to==.
sender_notification_permission
This takes into account the current power levels in the room, ensuring the sender of the event has high enough power to trigger the notification.
Parameters:
key: A string that determines the power level the sender must have to trigger notifications of a given type, such asroom. Refer to the m.room.power_levels event schema for information about what the defaults are and how to interpret the event. Thekeyis used to look up the power level required to send a notification type from thenotificationsobject in the power level event content.
Predefined Rules
Homeservers can specify "server-default rules". They operate at a lower
priority than "user-defined rules", except for the .m.rule.master rule
which has always a higher priority than any other rule. The rule_id
for all server-default rules MUST start with a dot (".") to identify
them as "server-default". The following server-default rules are
specified:
Default Override Rules
.m.rule.master
Matches all events. This can be enabled to turn off all push notifications. Unlike other server-default rules, this one has always a higher priority than other rules, even user defined ones. By default this rule is disabled.
Definition:
{
"rule_id": ".m.rule.master",
"default": true,
"enabled": false,
"conditions": [],
"actions": []
}
.m.rule.suppress_notices
Matches messages with a msgtype of notice.
Definition:
{
"rule_id": ".m.rule.suppress_notices",
"default": true,
"enabled": true,
"conditions": [
{
"kind": "event_match",
"key": "content.msgtype",
"pattern": "m.notice",
}
],
"actions": []
}
.m.rule.invite_for_me
Matches any invites to a new room for this user.
Definition:
{
"rule_id": ".m.rule.invite_for_me",
"default": true,
"enabled": true,
"conditions": [
{
"key": "type",
"kind": "event_match",
"pattern": "m.room.member"
},
{
"key": "content.membership",
"kind": "event_match",
"pattern": "invite"
},
{
"key": "state_key",
"kind": "event_match",
"pattern": "[the user's Matrix ID]"
}
],
"actions": [
"notify",
{
"set_tweak": "sound",
"value": "default"
}
]
}
.m.rule.member_event
Matches any m.room.member_event.
Definition:
{
"rule_id": ".m.rule.member_event",
"default": true,
"enabled": true,
"conditions": [
{
"key": "type",
"kind": "event_match",
"pattern": "m.room.member"
}
],
"actions": []
}
{{< added-in v="1.7" >}}
Matches any message which contains the user's Matrix ID in the list of user_ids
under the m.mentions property.
Definition:
{
"rule_id": ".m.rule.is_user_mention",
"default": true,
"enabled": true,
"conditions": [
{
"kind": "event_property_contains",
"key": "content.m\\.mentions.user_ids",
"value": "[the user's Matrix ID]"
}
],
"actions": [
"notify",
{
"set_tweak": "sound",
"value": "default"
},
{
"set_tweak": "highlight"
}
]
}
{{% changed-in v="1.7" %}}
As of v1.7, this rule is deprecated and should only be enabled if the event
does not have an m.mentions property.
Matches any message whose content contains the user's current display name in the room in which it was sent.
Definition:
{
"rule_id": ".m.rule.contains_display_name",
"default": true,
"enabled": true,
"conditions": [
{
"kind": "contains_display_name"
}
],
"actions": [
"notify",
{
"set_tweak": "sound",
"value": "default"
},
{
"set_tweak": "highlight"
}
]
}
{{< added-in v="1.7" >}}
Matches any message from a sender with the proper power level with the room
property of the m.mentions property set to true.
Definition:
{
"rule_id": ".m.rule.is_room_mention",
"default": true,
"enabled": true,
"conditions": [
{
"kind": "event_property_is",
"key": "content.m\\.mentions.room",
"value": true
},
{
"kind": "sender_notification_permission",
"key": "room"
}
],
"actions": [
"notify",
{
"set_tweak": "highlight"
}
]
}
{{% changed-in v="1.7" %}}
As of v1.7, this rule is deprecated and should only be enabled if the event
does not have an m.mentions property.
Matches any message from a sender with the proper power level whose content
contains the text @room, signifying the whole room should be notified of
the event.
Definition:
{
"rule_id": ".m.rule.roomnotif",
"default": true,
"enabled": true,
"conditions": [
{
"kind": "event_match",
"key": "content.body",
"pattern": "@room"
},
{
"kind": "sender_notification_permission",
"key": "room"
}
],
"actions": [
"notify",
{
"set_tweak": "highlight"
}
]
}
Matches any state event whose type is m.room.tombstone. This is
intended to notify users of a room when it is upgraded, similar to what
an @room notification would accomplish.
Definition:
{
"rule_id": ".m.rule.tombstone",
"default": true,
"enabled": true,
"conditions": [
{
"kind": "event_match",
"key": "type",
"pattern": "m.room.tombstone"
},
{
"kind": "event_match",
"key": "state_key",
"pattern": ""
}
],
"actions": [
"notify",
{
"set_tweak": "highlight"
}
]
}
{{% added-in v="1.7" %}}
Matches any event whose type is m.reaction. This suppresses notifications for m.reaction events.
Definition:
{
"rule_id": ".m.rule.reaction",
"default": true,
"enabled": true,
"conditions": [
{
"kind": "event_match",
"key": "type",
"pattern": "m.reaction"
}
],
"actions": []
}
.m.rule.room.server_acl
{{% added-in v="1.4" %}}
Suppresses notifications for m.room.server_acl events.
Definition:
{
"rule_id": ".m.rule.room.server_acl",
"default": true,
"enabled": true,
"conditions": [
{
"kind": "event_match",
"key": "type",
"pattern": "m.room.server_acl"
},
{
"kind": "event_match",
"key": "state_key",
"pattern": ""
}
],
"actions": []
}
.m.rule.suppress_edits
{{% added-in v="1.9" %}}
Suppresses notifications related to event replacements.
Definition:
{
"rule_id": ".m.rule.suppress_edits",
"default": true,
"enabled": true,
"conditions": [
{
"kind": "event_property_is",
"key": "content.m\\.relates_to.rel_type",
"value": "m.replace"
}
],
"actions": []
}
Default Content Rules
{{% changed-in v="1.7" %}}
As of v1.7, this rule is deprecated and should only be enabled if the event
does not have an m.mentions property.
Matches any message whose content contains the local part of the user's Matrix ID, separated by word boundaries.
Definition (as a content rule):
{
"rule_id": ".m.rule.contains_user_name",
"default": true,
"enabled": true,
"pattern": "[the local part of the user's Matrix ID]",
"actions": [
"notify",
{
"set_tweak": "sound",
"value": "default"
},
{
"set_tweak": "highlight"
}
]
}
Default Underride Rules
.m.rule.call
Matches any incoming VOIP call.
Definition:
{
"rule_id": ".m.rule.call",
"default": true,
"enabled": true,
"conditions": [
{
"key": "type",
"kind": "event_match",
"pattern": "m.call.invite"
}
],
"actions": [
"notify",
{
"set_tweak": "sound",
"value": "ring"
}
]
}
.m.rule.encrypted_room_one_to_one
Matches any encrypted event sent in a room with exactly two members. Unlike other push rules, this rule cannot be matched against the content of the event by nature of it being encrypted. This causes the rule to be an "all or nothing" match where it either matches all events that are encrypted (in 1:1 rooms) or none.
Definition:
{
"rule_id": ".m.rule.encrypted_room_one_to_one",
"default": true,
"enabled": true,
"conditions": [
{
"kind": "room_member_count",
"is": "2"
},
{
"kind": "event_match",
"key": "type",
"pattern": "m.room.encrypted"
}
],
"actions": [
"notify",
{
"set_tweak": "sound",
"value": "default"
}
]
}
.m.rule.room_one_to_one
Matches any message sent in a room with exactly two members.
Definition:
{
"rule_id": ".m.rule.room_one_to_one",
"default": true,
"enabled": true,
"conditions": [
{
"kind": "room_member_count",
"is": "2"
},
{
"kind": "event_match",
"key": "type",
"pattern": "m.room.message"
}
],
"actions": [
"notify",
{
"set_tweak": "sound",
"value": "default"
}
]
}
.m.rule.message
Matches all chat messages.
Definition:
{
"rule_id": ".m.rule.message",
"default": true,
"enabled": true,
"conditions": [
{
"kind": "event_match",
"key": "type",
"pattern": "m.room.message"
}
],
"actions": [
"notify"
]
}
.m.rule.encrypted
Matches all encrypted events. Unlike other push rules, this rule cannot be matched against the content of the event by nature of it being encrypted. This causes the rule to be an "all or nothing" match where it either matches all events that are encrypted (in group rooms) or none.
Definition:
{
"rule_id": ".m.rule.encrypted",
"default": true,
"enabled": true,
"conditions": [
{
"kind": "event_match",
"key": "type",
"pattern": "m.room.encrypted"
}
],
"actions": [
"notify"
]
}
Push Rules: API
Clients can retrieve, add, modify and remove push rules globally or per-device using the APIs below.
{{% http-api spec="client-server" api="pushrules" %}}
Push Rules: Events
When a user changes their push rules a m.push_rules event is sent to
all clients in the account_data section of their next /sync request.
The content of the event is the current push rules for the user.
{{% event event="m.push_rules" %}}
Examples
To create a rule that suppresses notifications for the room with ID
!dj234r78wl45Gh4D:matrix.org:
curl -X PUT -H "Content-Type: application/json" "https://example.com/_matrix/client/v3/pushrules/global/room/%21dj234r78wl45Gh4D%3Amatrix.org?access_token=123456" -d \
'{
"actions" : []
}'
To suppress notifications for the user @spambot:matrix.org:
curl -X PUT -H "Content-Type: application/json" "https://example.com/_matrix/client/v3/pushrules/global/sender/%40spambot%3Amatrix.org?access_token=123456" -d \
'{
"actions" : []
}'
To always notify for messages that contain the work 'cake' and set a
specific sound (with a rule_id of SSByZWFsbHkgbGlrZSBjYWtl):
curl -X PUT -H "Content-Type: application/json" "https://example.com/_matrix/client/v3/pushrules/global/content/SSByZWFsbHkgbGlrZSBjYWtl?access_token=123456" -d \
'{
"pattern": "cake",
"actions" : ["notify", {"set_tweak":"sound", "value":"cakealarm.wav"}]
}'
To add a rule suppressing notifications for messages starting with 'cake' but ending with 'lie', superseding the previous rule:
curl -X PUT -H "Content-Type: application/json" "https://example.com/_matrix/client/v3/pushrules/global/content/U3BvbmdlIGNha2UgaXMgYmVzdA?access_token=123456&before=SSByZWFsbHkgbGlrZSBjYWtl" -d \
'{
"pattern": "cake*lie",
"actions" : ["notify"]
}'
To add a custom sound for notifications messages containing the word 'beer' in any rooms with 10 members or fewer (with greater importance than the room, sender and content rules):
curl -X PUT -H "Content-Type: application/json" "https://example.com/_matrix/client/v3/pushrules/global/override/U2VlIHlvdSBpbiBUaGUgRHVrZQ?access_token=123456" -d \
'{
"conditions": [
{"kind": "event_match", "key": "content.body", "pattern": "beer" },
{"kind": "room_member_count", "is": "<=10"}
],
"actions" : [
"notify",
{"set_tweak":"sound", "value":"beeroclock.wav"}
]
}'
Client behaviour
Clients MUST configure a Pusher before they will receive push notifications. There is a single API endpoint for this, as described below.
{{% http-api spec="client-server" api="pusher" %}}
Listing Notifications
A client can retrieve a list of events that it has been notified about. This may be useful so that users can see a summary of what important messages they have received.
{{% http-api spec="client-server" api="notifications" %}}
Receiving notifications
Servers MUST include the number of unread notifications in a client's
/sync stream, and MUST update it as it changes. Notifications are
determined by the push rules which apply to an event.
For encrypted events, the homeserver has limited access to the event content and properly processing push rules falls on the client. Clients should process push rules for each incoming event after decrypting them. This may result in needing to modify the number of unread notifications received from the homeserver.
Marking notifications as read
When the user updates their read receipt (either by using the API or by
sending an event), notifications prior to and including that event MUST
be marked as read. Which specific events are affected can vary depending
on whether a threaded read receipt was used.
Note that users can send both an m.read and m.read.private receipt,
both of which are capable of clearing notifications.
If the user has both m.read and m.read.private set in the room then
the receipt which is more recent/ahead must be used to determine where
the user has read up to. For example, given an oldest-first set of events A,
B, C, and D the m.read receipt could be at event C and m.read.private
at event A - the user is considered to have read up to event C. If the
m.read.private receipt is then updated to point to B or C, the user's
notification state doesn't change (the m.read receipt is still more
ahead), however if the m.read.private receipt were to be updated to
event D then the user has read up to D (the m.read receipt is now
behind the m.read.private receipt).
{{< added-in v="1.4" >}} When handling threaded read receipts, the server
is to partition the notification count to each thread (with the main timeline
being its own thread). To determine if an event is part of a thread the
server follows the event relationship
until it finds a thread root (as specified by the threading module),
however it is not recommended that the server traverse infinitely. Instead,
implementations are encouraged to do a maximum of 3 hops to find a thread
before deciding that the event does not belong to a thread. This is primarily
to ensure that future events, like m.reaction, are correctly considered
"part of" a given thread.
Server behaviour
When receiving a new event homeservers process push rules for each of the local users in the room (excluding the sender). This may result in:
- Generating a new number of unread notifications for the user.
- Making a request to the configured push gateway.
The updated notification count from a new event MUST appear in the same /sync
response as the event itself.
Push Gateway behaviour
Recommendations for APNS
The exact format for sending APNS notifications is flexible and up to the client app and its push gateway to agree on. As APNS requires that the sender has a private key owned by the app developer, each app must have its own push gateway. It is recommended that:
- The APNS token be base64 encoded and used as the pushkey.
- A different app_id be used for apps on the production and sandbox APS environments.
- APNS push gateways do not attempt to wait for errors from the APNS gateway before returning and instead to store failures and return 'rejected' responses next time that pushkey is used.
Security considerations
Clients specify the Push Gateway URL to use to send event notifications to. This URL should be over HTTPS and never over HTTP.
As push notifications will pass through a Push Provider, message content shouldn't be sent in the push itself where possible. Instead, Push Gateways should send a "sync" command to instruct the client to get new events from the homeserver directly.