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Spam checker callbacks can be registered using the module API's <code>register_spam_checker_callbacks</code> method.</p> <h2 id="callbacks"><a class="header" href="#callbacks">Callbacks</a></h2> <p>The available spam checker callbacks are:</p> <h3 id="check_event_for_spam"><a class="header" href="#check_event_for_spam"><code>check_event_for_spam</code></a></h3> <p><em>First introduced in Synapse v1.37.0</em></p> <pre><code class="language-python">async def check_event_for_spam(event: "synapse.events.EventBase") -> Union[bool, str] </code></pre> <p>Called when receiving an event from a client or via federation. The module can return either a <code>bool</code> to indicate whether the event must be rejected because of spam, or a <code>str</code> to indicate the event must be rejected because of spam and to give a rejection reason to forward to clients.</p> <p>If multiple modules implement this callback, they will be considered in order. If a callback returns <code>False</code>, Synapse falls through to the next one. The value of the first callback that does not return <code>False</code> will be used. If this happens, Synapse will not call any of the subsequent implementations of this callback.</p> <h3 id="user_may_join_room"><a class="header" href="#user_may_join_room"><code>user_may_join_room</code></a></h3> <p><em>First introduced in Synapse v1.37.0</em></p> <pre><code class="language-python">async def user_may_join_room(user: str, room: str, is_invited: bool) -> bool </code></pre> <p>Called when a user is trying to join a room. The module must return a <code>bool</code> to indicate whether the user can join the room. The user is represented by their Matrix user ID (e.g. <code>@alice:example.com</code>) and the room is represented by its Matrix ID (e.g. <code>!room:example.com</code>). The module is also given a boolean to indicate whether the user currently has a pending invite in the room.</p> <p>This callback isn't called if the join is performed by a server administrator, or in the context of a room creation.</p> <p>If multiple modules implement this callback, they will be considered in order. If a callback returns <code>True</code>, Synapse falls through to the next one. The value of the first callback that does not return <code>True</code> will be used. If this happens, Synapse will not call any of the subsequent implementations of this callback.</p> <h3 id="user_may_invite"><a class="header" href="#user_may_invite"><code>user_may_invite</code></a></h3> <p><em>First introduced in Synapse v1.37.0</em></p> <pre><code class="language-python">async def user_may_invite(inviter: str, invitee: str, room_id: str) -> bool </code></pre> <p>Called when processing an invitation. The module must return a <code>bool</code> indicating whether the inviter can invite the invitee to the given room. Both inviter and invitee are represented by their Matrix user ID (e.g. <code>@alice:example.com</code>).</p> <p>If multiple modules implement this callback, they will be considered in order. If a callback returns <code>True</code>, Synapse falls through to the next one. The value of the first callback that does not return <code>True</code> will be used. If this happens, Synapse will not call any of the subsequent implementations of this callback.</p> <h3 id="user_may_send_3pid_invite"><a class="header" href="#user_may_send_3pid_invite"><code>user_may_send_3pid_invite</code></a></h3> <p><em>First introduced in Synapse v1.45.0</em></p> <pre><code class="language-python">async def user_may_send_3pid_invite( inviter: str, medium: str, address: str, room_id: str, ) -> bool </code></pre> <p>Called when processing an invitation using a third-party identifier (also called a 3PID, e.g. an email address or a phone number). The module must return a <code>bool</code> indicating whether the inviter can invite the invitee to the given room.</p> <p>The inviter is represented by their Matrix user ID (e.g. <code>@alice:example.com</code>), and the invitee is represented by its medium (e.g. "email") and its address (e.g. <code>alice@example.com</code>). See <a href="https://matrix.org/docs/spec/appendices#pid-types">the Matrix specification</a> for more information regarding third-party identifiers.</p> <p>For example, a call to this callback to send an invitation to the email address <code>alice@example.com</code> would look like this:</p> <pre><code class="language-python">await user_may_send_3pid_invite( "@bob:example.com", # The inviter's user ID "email", # The medium of the 3PID to invite "alice@example.com", # The address of the 3PID to invite "!some_room:example.com", # The ID of the room to send the invite into ) </code></pre> <p><strong>Note</strong>: If the third-party identifier is already associated with a matrix user ID, <a href="#user_may_invite"><code>user_may_invite</code></a> will be used instead.</p> <p>If multiple modules implement this callback, they will be considered in order. If a callback returns <code>True</code>, Synapse falls through to the next one. The value of the first callback that does not return <code>True</code> will be used. If this happens, Synapse will not call any of the subsequent implementations of this callback.</p> <h3 id="user_may_create_room"><a class="header" href="#user_may_create_room"><code>user_may_create_room</code></a></h3> <p><em>First introduced in Synapse v1.37.0</em></p> <pre><code class="language-python">async def user_may_create_room(user: str) -> bool </code></pre> <p>Called when processing a room creation request. The module must return a <code>bool</code> indicating whether the given user (represented by their Matrix user ID) is allowed to create a room.</p> <p>If multiple modules implement this callback, they will be considered in order. If a callback returns <code>True</code>, Synapse falls through to the next one. The value of the first callback that does not return <code>True</code> will be used. If this happens, Synapse will not call any of the subsequent implementations of this callback.</p> <h3 id="user_may_create_room_alias"><a class="header" href="#user_may_create_room_alias"><code>user_may_create_room_alias</code></a></h3> <p><em>First introduced in Synapse v1.37.0</em></p> <pre><code class="language-python">async def user_may_create_room_alias(user: str, room_alias: "synapse.types.RoomAlias") -> bool </code></pre> <p>Called when trying to associate an alias with an existing room. The module must return a <code>bool</code> indicating whether the given user (represented by their Matrix user ID) is allowed to set the given alias.</p> <p>If multiple modules implement this callback, they will be considered in order. If a callback returns <code>True</code>, Synapse falls through to the next one. The value of the first callback that does not return <code>True</code> will be used. If this happens, Synapse will not call any of the subsequent implementations of this callback.</p> <h3 id="user_may_publish_room"><a class="header" href="#user_may_publish_room"><code>user_may_publish_room</code></a></h3> <p><em>First introduced in Synapse v1.37.0</em></p> <pre><code class="language-python">async def user_may_publish_room(user: str, room_id: str) -> bool </code></pre> <p>Called when trying to publish a room to the homeserver's public rooms directory. The module must return a <code>bool</code> indicating whether the given user (represented by their Matrix user ID) is allowed to publish the given room.</p> <p>If multiple modules implement this callback, they will be considered in order. If a callback returns <code>True</code>, Synapse falls through to the next one. The value of the first callback that does not return <code>True</code> will be used. If this happens, Synapse will not call any of the subsequent implementations of this callback.</p> <h3 id="check_username_for_spam"><a class="header" href="#check_username_for_spam"><code>check_username_for_spam</code></a></h3> <p><em>First introduced in Synapse v1.37.0</em></p> <pre><code class="language-python">async def check_username_for_spam(user_profile: Dict[str, str]) -> bool </code></pre> <p>Called when computing search results in the user directory. The module must return a <code>bool</code> indicating whether the given user profile can appear in search results. The profile is represented as a dictionary with the following keys:</p> <ul> <li><code>user_id</code>: The Matrix ID for this user.</li> <li><code>display_name</code>: The user's display name.</li> <li><code>avatar_url</code>: The <code>mxc://</code> URL to the user's avatar.</li> </ul> <p>The module is given a copy of the original dictionary, so modifying it from within the module cannot modify a user's profile when included in user directory search results.</p> <p>If multiple modules implement this callback, they will be considered in order. If a callback returns <code>False</code>, Synapse falls through to the next one. The value of the first callback that does not return <code>False</code> will be used. If this happens, Synapse will not call any of the subsequent implementations of this callback.</p> <h3 id="check_registration_for_spam"><a class="header" href="#check_registration_for_spam"><code>check_registration_for_spam</code></a></h3> <p><em>First introduced in Synapse v1.37.0</em></p> <pre><code class="language-python">async def check_registration_for_spam( email_threepid: Optional[dict], username: Optional[str], request_info: Collection[Tuple[str, str]], auth_provider_id: Optional[str] = None, ) -> "synapse.spam_checker_api.RegistrationBehaviour" </code></pre> <p>Called when registering a new user. The module must return a <code>RegistrationBehaviour</code> indicating whether the registration can go through or must be denied, or whether the user may be allowed to register but will be shadow banned.</p> <p>The arguments passed to this callback are:</p> <ul> <li><code>email_threepid</code>: The email address used for registering, if any.</li> <li><code>username</code>: The username the user would like to register. Can be <code>None</code>, meaning that Synapse will generate one later.</li> <li><code>request_info</code>: A collection of tuples, which first item is a user agent, and which second item is an IP address. These user agents and IP addresses are the ones that were used during the registration process.</li> <li><code>auth_provider_id</code>: The identifier of the SSO authentication provider, if any.</li> </ul> <p>If multiple modules implement this callback, they will be considered in order. If a callback returns <code>RegistrationBehaviour.ALLOW</code>, Synapse falls through to the next one. The value of the first callback that does not return <code>RegistrationBehaviour.ALLOW</code> will be used. If this happens, Synapse will not call any of the subsequent implementations of this callback.</p> <h3 id="check_media_file_for_spam"><a class="header" href="#check_media_file_for_spam"><code>check_media_file_for_spam</code></a></h3> <p><em>First introduced in Synapse v1.37.0</em></p> <pre><code class="language-python">async def check_media_file_for_spam( file_wrapper: "synapse.rest.media.v1.media_storage.ReadableFileWrapper", file_info: "synapse.rest.media.v1._base.FileInfo", ) -> bool </code></pre> <p>Called when storing a local or remote file. The module must return a boolean indicating whether the given file can be stored in the homeserver's media store.</p> <p>If multiple modules implement this callback, they will be considered in order. If a callback returns <code>False</code>, Synapse falls through to the next one. The value of the first callback that does not return <code>False</code> will be used. If this happens, Synapse will not call any of the subsequent implementations of this callback.</p> <h2 id="example"><a class="header" href="#example">Example</a></h2> <p>The example below is a module that implements the spam checker callback <code>check_event_for_spam</code> to deny any message sent by users whose Matrix user IDs are mentioned in a configured list, and registers a web resource to the path <code>/_synapse/client/list_spam_checker/is_evil</code> that returns a JSON object indicating whether the provided user appears in that list.</p> <pre><code class="language-python">import json from typing import Union from twisted.web.resource import Resource from twisted.web.server import Request from synapse.module_api import ModuleApi class IsUserEvilResource(Resource): def __init__(self, config): super(IsUserEvilResource, self).__init__() self.evil_users = config.get("evil_users") or [] def render_GET(self, request: Request): user = request.args.get(b"user")[0].decode() request.setHeader(b"Content-Type", b"application/json") return json.dumps({"evil": user in self.evil_users}).encode() class ListSpamChecker: def __init__(self, config: dict, api: ModuleApi): self.api = api self.evil_users = config.get("evil_users") or [] self.api.register_spam_checker_callbacks( check_event_for_spam=self.check_event_for_spam, ) self.api.register_web_resource( path="/_synapse/client/list_spam_checker/is_evil", resource=IsUserEvilResource(config), ) async def check_event_for_spam(self, event: "synapse.events.EventBase") -> Union[bool, str]: return event.sender not in self.evil_users </code></pre> </main> <nav class="nav-wrapper" aria-label="Page navigation"> <!-- Mobile navigation buttons --> <a rel="prev" href="../modules/writing_a_module.html" class="mobile-nav-chapters previous" title="Previous chapter" aria-label="Previous chapter" aria-keyshortcuts="Left"> <i class="fa fa-angle-left"></i> </a> <a rel="next" href="../modules/third_party_rules_callbacks.html" class="mobile-nav-chapters next" title="Next chapter" aria-label="Next chapter" aria-keyshortcuts="Right"> <i class="fa fa-angle-right"></i> </a> <div style="clear: both"></div> </nav> </div> </div> <nav class="nav-wide-wrapper" aria-label="Page navigation"> <a rel="prev" href="../modules/writing_a_module.html" class="nav-chapters previous" title="Previous chapter" aria-label="Previous chapter" aria-keyshortcuts="Left"> <i class="fa fa-angle-left"></i> </a> <a rel="next" href="../modules/third_party_rules_callbacks.html" class="nav-chapters next" title="Next chapter" aria-label="Next chapter" aria-keyshortcuts="Right"> <i class="fa fa-angle-right"></i> </a> </nav> </div> <script type="text/javascript"> window.playground_copyable = true; </script> <script src="../elasticlunr.min.js" type="text/javascript" charset="utf-8"></script> <script src="../mark.min.js" type="text/javascript" charset="utf-8"></script> <script src="../searcher.js" type="text/javascript" charset="utf-8"></script> <script src="../clipboard.min.js" type="text/javascript" charset="utf-8"></script> <script src="../highlight.js" type="text/javascript" charset="utf-8"></script> <script src="../book.js" type="text/javascript" charset="utf-8"></script> <!-- Custom JS scripts --> <script type="text/javascript" src="../docs/website_files/table-of-contents.js"></script> <script type="text/javascript" src="../docs/website_files/version-picker.js"></script> <script type="text/javascript" src="../docs/website_files/version.js"></script> </body> </html>