summary refs log tree commit diff
path: root/v1.63/modules/spam_checker_callbacks.html
blob: 49cb139492e92a593e754591e4659eee81da8d58 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
<!DOCTYPE HTML>
<html lang="en" class="sidebar-visible no-js light">
    <head>
        <!-- Book generated using mdBook -->
        <meta charset="UTF-8">
        <title>Spam checker callbacks - Synapse</title>
        <!-- Custom HTML head -->
        <meta content="text/html; charset=utf-8" http-equiv="Content-Type">
        <meta name="description" content="">
        <meta name="viewport" content="width=device-width, initial-scale=1">
        <meta name="theme-color" content="#ffffff" />

        <link rel="icon" href="../favicon.svg">
        <link rel="shortcut icon" href="../favicon.png">
        <link rel="stylesheet" href="../css/variables.css">
        <link rel="stylesheet" href="../css/general.css">
        <link rel="stylesheet" href="../css/chrome.css">
        <link rel="stylesheet" href="../css/print.css" media="print">
        <!-- Fonts -->
        <link rel="stylesheet" href="../FontAwesome/css/font-awesome.css">
        <link rel="stylesheet" href="../fonts/fonts.css">
        <!-- Highlight.js Stylesheets -->
        <link rel="stylesheet" href="../highlight.css">
        <link rel="stylesheet" href="../tomorrow-night.css">
        <link rel="stylesheet" href="../ayu-highlight.css">

        <!-- Custom theme stylesheets -->
        <link rel="stylesheet" href="../docs/website_files/table-of-contents.css">
        <link rel="stylesheet" href="../docs/website_files/remove-nav-buttons.css">
        <link rel="stylesheet" href="../docs/website_files/indent-section-headers.css">
    </head>
    <body>
        <!-- Provide site root to javascript -->
        <script type="text/javascript">
            var path_to_root = "../";
            var default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? "navy" : "light";
        </script>

        <!-- Work around some values being stored in localStorage wrapped in quotes -->
        <script type="text/javascript">
            try {
                var theme = localStorage.getItem('mdbook-theme');
                var sidebar = localStorage.getItem('mdbook-sidebar');
                if (theme.startsWith('"') && theme.endsWith('"')) {
                    localStorage.setItem('mdbook-theme', theme.slice(1, theme.length - 1));
                }
                if (sidebar.startsWith('"') && sidebar.endsWith('"')) {
                    localStorage.setItem('mdbook-sidebar', sidebar.slice(1, sidebar.length - 1));
                }
            } catch (e) { }
        </script>

        <!-- Set the theme before any content is loaded, prevents flash -->
        <script type="text/javascript">
            var theme;
            try { theme = localStorage.getItem('mdbook-theme'); } catch(e) { }
            if (theme === null || theme === undefined) { theme = default_theme; }
            var html = document.querySelector('html');
            html.classList.remove('no-js')
            html.classList.remove('light')
            html.classList.add(theme);
            html.classList.add('js');
        </script>

        <!-- Hide / unhide sidebar before it is displayed -->
        <script type="text/javascript">
            var html = document.querySelector('html');
            var sidebar = 'hidden';
            if (document.body.clientWidth >= 1080) {
                try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                sidebar = sidebar || 'visible';
            }
            html.classList.remove('sidebar-visible');
            html.classList.add("sidebar-" + sidebar);
        </script>

        <nav id="sidebar" class="sidebar" aria-label="Table of contents">
            <div class="sidebar-scrollbox">
                <ol class="chapter"><li class="chapter-item expanded affix "><li class="part-title">Introduction</li><li class="chapter-item expanded "><a href="../welcome_and_overview.html">Welcome and Overview</a></li><li class="chapter-item expanded affix "><li class="part-title">Setup</li><li class="chapter-item expanded "><a href="../setup/installation.html">Installation</a></li><li class="chapter-item expanded "><a href="../postgres.html">Using Postgres</a></li><li class="chapter-item expanded "><a href="../reverse_proxy.html">Configuring a Reverse Proxy</a></li><li class="chapter-item expanded "><a href="../setup/forward_proxy.html">Configuring a Forward/Outbound Proxy</a></li><li class="chapter-item expanded "><a href="../turn-howto.html">Configuring a Turn Server</a></li><li class="chapter-item expanded "><a href="../delegate.html">Delegation</a></li><li class="chapter-item expanded affix "><li class="part-title">Upgrading</li><li class="chapter-item expanded "><a href="../upgrade.html">Upgrading between Synapse Versions</a></li><li class="chapter-item expanded affix "><li class="part-title">Usage</li><li class="chapter-item expanded "><a href="../federate.html">Federation</a></li><li class="chapter-item expanded "><a href="../usage/configuration/index.html">Configuration</a></li><li><ol class="section"><li class="chapter-item expanded "><a href="../usage/configuration/config_documentation.html">Configuration Manual</a></li><li class="chapter-item expanded "><a href="../usage/configuration/homeserver_sample_config.html">Homeserver Sample Config File</a></li><li class="chapter-item expanded "><a href="../usage/configuration/logging_sample_config.html">Logging Sample Config File</a></li><li class="chapter-item expanded "><a href="../structured_logging.html">Structured Logging</a></li><li class="chapter-item expanded "><a href="../templates.html">Templates</a></li><li class="chapter-item expanded "><a href="../usage/configuration/user_authentication/index.html">User Authentication</a></li><li><ol class="section"><li class="chapter-item expanded "><a href="../usage/configuration/user_authentication/single_sign_on/index.html">Single-Sign On</a></li><li><ol class="section"><li class="chapter-item expanded "><a href="../openid.html">OpenID Connect</a></li><li class="chapter-item expanded "><a href="../usage/configuration/user_authentication/single_sign_on/saml.html">SAML</a></li><li class="chapter-item expanded "><a href="../usage/configuration/user_authentication/single_sign_on/cas.html">CAS</a></li><li class="chapter-item expanded "><a href="../sso_mapping_providers.html">SSO Mapping Providers</a></li></ol></li><li class="chapter-item expanded "><a href="../password_auth_providers.html">Password Auth Providers</a></li><li class="chapter-item expanded "><a href="../jwt.html">JSON Web Tokens</a></li><li class="chapter-item expanded "><a href="../usage/configuration/user_authentication/refresh_tokens.html">Refresh Tokens</a></li></ol></li><li class="chapter-item expanded "><a href="../CAPTCHA_SETUP.html">Registration Captcha</a></li><li class="chapter-item expanded "><a href="../application_services.html">Application Services</a></li><li class="chapter-item expanded "><a href="../server_notices.html">Server Notices</a></li><li class="chapter-item expanded "><a href="../consent_tracking.html">Consent Tracking</a></li><li class="chapter-item expanded "><a href="../development/url_previews.html">URL Previews</a></li><li class="chapter-item expanded "><a href="../user_directory.html">User Directory</a></li><li class="chapter-item expanded "><a href="../message_retention_policies.html">Message Retention Policies</a></li><li class="chapter-item expanded "><a href="../modules/index.html">Pluggable Modules</a></li><li><ol class="section"><li class="chapter-item expanded "><a href="../modules/writing_a_module.html">Writing a module</a></li><li><ol class="section"><li class="chapter-item expanded "><a href="../modules/spam_checker_callbacks.html" class="active">Spam checker callbacks</a></li><li class="chapter-item expanded "><a href="../modules/third_party_rules_callbacks.html">Third-party rules callbacks</a></li><li class="chapter-item expanded "><a href="../modules/presence_router_callbacks.html">Presence router callbacks</a></li><li class="chapter-item expanded "><a href="../modules/account_validity_callbacks.html">Account validity callbacks</a></li><li class="chapter-item expanded "><a href="../modules/password_auth_provider_callbacks.html">Password auth provider callbacks</a></li><li class="chapter-item expanded "><a href="../modules/background_update_controller_callbacks.html">Background update controller callbacks</a></li><li class="chapter-item expanded "><a href="../modules/account_data_callbacks.html">Account data callbacks</a></li><li class="chapter-item expanded "><a href="../modules/porting_legacy_module.html">Porting a legacy module to the new interface</a></li></ol></li></ol></li><li class="chapter-item expanded "><a href="../workers.html">Workers</a></li><li><ol class="section"><li class="chapter-item expanded "><a href="../synctl_workers.html">Using synctl with Workers</a></li><li class="chapter-item expanded "><a href="../systemd-with-workers/index.html">Systemd</a></li></ol></li></ol></li><li class="chapter-item expanded "><a href="../usage/administration/index.html">Administration</a></li><li><ol class="section"><li class="chapter-item expanded "><a href="../usage/administration/admin_api/index.html">Admin API</a></li><li><ol class="section"><li class="chapter-item expanded "><a href="../admin_api/account_validity.html">Account Validity</a></li><li class="chapter-item expanded "><a href="../usage/administration/admin_api/background_updates.html">Background Updates</a></li><li class="chapter-item expanded "><a href="../admin_api/event_reports.html">Event Reports</a></li><li class="chapter-item expanded "><a href="../admin_api/media_admin_api.html">Media</a></li><li class="chapter-item expanded "><a href="../admin_api/purge_history_api.html">Purge History</a></li><li class="chapter-item expanded "><a href="../admin_api/register_api.html">Register Users</a></li><li class="chapter-item expanded "><a href="../usage/administration/admin_api/registration_tokens.html">Registration Tokens</a></li><li class="chapter-item expanded "><a href="../admin_api/room_membership.html">Manipulate Room Membership</a></li><li class="chapter-item expanded "><a href="../admin_api/rooms.html">Rooms</a></li><li class="chapter-item expanded "><a href="../admin_api/server_notices.html">Server Notices</a></li><li class="chapter-item expanded "><a href="../admin_api/statistics.html">Statistics</a></li><li class="chapter-item expanded "><a href="../admin_api/user_admin_api.html">Users</a></li><li class="chapter-item expanded "><a href="../admin_api/version_api.html">Server Version</a></li><li class="chapter-item expanded "><a href="../usage/administration/admin_api/federation.html">Federation</a></li></ol></li><li class="chapter-item expanded "><a href="../manhole.html">Manhole</a></li><li class="chapter-item expanded "><a href="../metrics-howto.html">Monitoring</a></li><li><ol class="section"><li class="chapter-item expanded "><a href="../usage/administration/monitoring/reporting_homeserver_usage_statistics.html">Reporting Homeserver Usage Statistics</a></li></ol></li><li class="chapter-item expanded "><a href="../usage/administration/understanding_synapse_through_grafana_graphs.html">Understanding Synapse Through Grafana Graphs</a></li><li class="chapter-item expanded "><a href="../usage/administration/useful_sql_for_admins.html">Useful SQL for Admins</a></li><li class="chapter-item expanded "><a href="../usage/administration/database_maintenance_tools.html">Database Maintenance Tools</a></li><li class="chapter-item expanded "><a href="../usage/administration/state_groups.html">State Groups</a></li><li class="chapter-item expanded "><a href="../usage/administration/request_log.html">Request log format</a></li><li class="chapter-item expanded "><a href="../usage/administration/admin_faq.html">Admin FAQ</a></li><li class="chapter-item expanded "><div>Scripts</div></li></ol></li><li class="chapter-item expanded "><li class="part-title">Development</li><li class="chapter-item expanded "><a href="../development/contributing_guide.html">Contributing Guide</a></li><li class="chapter-item expanded "><a href="../code_style.html">Code Style</a></li><li class="chapter-item expanded "><a href="../development/reviews.html">Reviewing Code</a></li><li class="chapter-item expanded "><a href="../development/releases.html">Release Cycle</a></li><li class="chapter-item expanded "><a href="../development/git.html">Git Usage</a></li><li class="chapter-item expanded "><div>Testing</div></li><li><ol class="section"><li class="chapter-item expanded "><a href="../development/demo.html">Demo scripts</a></li></ol></li><li class="chapter-item expanded "><a href="../opentracing.html">OpenTracing</a></li><li class="chapter-item expanded "><a href="../development/database_schema.html">Database Schemas</a></li><li class="chapter-item expanded "><a href="../development/experimental_features.html">Experimental features</a></li><li class="chapter-item expanded "><a href="../development/dependencies.html">Dependency management</a></li><li class="chapter-item expanded "><div>Synapse Architecture</div></li><li><ol class="section"><li class="chapter-item expanded "><a href="../development/synapse_architecture/cancellation.html">Cancellation</a></li><li class="chapter-item expanded "><a href="../log_contexts.html">Log Contexts</a></li><li class="chapter-item expanded "><a href="../replication.html">Replication</a></li><li class="chapter-item expanded "><a href="../tcp_replication.html">TCP Replication</a></li></ol></li><li class="chapter-item expanded "><a href="../development/internal_documentation/index.html">Internal Documentation</a></li><li><ol class="section"><li class="chapter-item expanded "><div>Single Sign-On</div></li><li><ol class="section"><li class="chapter-item expanded "><a href="../development/saml.html">SAML</a></li><li class="chapter-item expanded "><a href="../development/cas.html">CAS</a></li></ol></li><li class="chapter-item expanded "><a href="../development/room-dag-concepts.html">Room DAG concepts</a></li><li class="chapter-item expanded "><div>State Resolution</div></li><li><ol class="section"><li class="chapter-item expanded "><a href="../auth_chain_difference_algorithm.html">The Auth Chain Difference Algorithm</a></li></ol></li><li class="chapter-item expanded "><a href="../media_repository.html">Media Repository</a></li><li class="chapter-item expanded "><a href="../room_and_user_statistics.html">Room and User Statistics</a></li></ol></li><li class="chapter-item expanded "><div>Scripts</div></li><li class="chapter-item expanded affix "><li class="part-title">Other</li><li class="chapter-item expanded "><a href="../deprecation_policy.html">Dependency Deprecation Policy</a></li><li class="chapter-item expanded "><a href="../other/running_synapse_on_single_board_computers.html">Running Synapse on a Single-Board Computer</a></li></ol>
            </div>
            <div id="sidebar-resize-handle" class="sidebar-resize-handle"></div>
        </nav>

        <div id="page-wrapper" class="page-wrapper">

            <div class="page">
                <div id="menu-bar-hover-placeholder"></div>
                <div id="menu-bar" class="menu-bar sticky bordered">
                    <div class="left-buttons">
                        <button id="sidebar-toggle" class="icon-button" type="button" title="Toggle Table of Contents" aria-label="Toggle Table of Contents" aria-controls="sidebar">
                            <i class="fa fa-bars"></i>
                        </button>
                        <button id="theme-toggle" class="icon-button" type="button" title="Change theme" aria-label="Change theme" aria-haspopup="true" aria-expanded="false" aria-controls="theme-list">
                            <i class="fa fa-paint-brush"></i>
                        </button>
                        <ul id="theme-list" class="theme-popup" aria-label="Themes" role="menu">
                            <li role="none"><button role="menuitem" class="theme" id="light">Light (default)</button></li>
                            <li role="none"><button role="menuitem" class="theme" id="rust">Rust</button></li>
                            <li role="none"><button role="menuitem" class="theme" id="coal">Coal</button></li>
                            <li role="none"><button role="menuitem" class="theme" id="navy">Navy</button></li>
                            <li role="none"><button role="menuitem" class="theme" id="ayu">Ayu</button></li>
                        </ul>
                        <button id="search-toggle" class="icon-button" type="button" title="Search. (Shortkey: s)" aria-label="Toggle Searchbar" aria-expanded="false" aria-keyshortcuts="S" aria-controls="searchbar">
                            <i class="fa fa-search"></i>
                        </button>
                    </div>

                    <h1 class="menu-title">Synapse</h1>

                    <div class="right-buttons">
                        <a href="../print.html" title="Print this book" aria-label="Print this book">
                            <i id="print-button" class="fa fa-print"></i>
                        </a>
                        <a href="https://github.com/matrix-org/synapse" title="Git repository" aria-label="Git repository">
                            <i id="git-repository-button" class="fa fa-github"></i>
                        </a>
                        <a href="https://github.com/matrix-org/synapse/edit/develop/docs/modules/spam_checker_callbacks.md" title="Suggest an edit" aria-label="Suggest an edit">
                            <i id="git-edit-button" class="fa fa-edit"></i>
                        </a>
                    </div>
                </div>

                <div id="search-wrapper" class="hidden">
                    <form id="searchbar-outer" class="searchbar-outer">
                        <input type="search" id="searchbar" name="searchbar" placeholder="Search this book ..." aria-controls="searchresults-outer" aria-describedby="searchresults-header">
                    </form>
                    <div id="searchresults-outer" class="searchresults-outer hidden">
                        <div id="searchresults-header" class="searchresults-header"></div>
                        <ul id="searchresults">
                        </ul>
                    </div>
                </div>
                <!-- Apply ARIA attributes after the sidebar and the sidebar toggle button are added to the DOM -->
                <script type="text/javascript">
                    document.getElementById('sidebar-toggle').setAttribute('aria-expanded', sidebar === 'visible');
                    document.getElementById('sidebar').setAttribute('aria-hidden', sidebar !== 'visible');
                    Array.from(document.querySelectorAll('#sidebar a')).forEach(function(link) {
                        link.setAttribute('tabIndex', sidebar === 'visible' ? 0 : -1);
                    });
                </script>

                <div id="content" class="content">
                    <main>
                        <!-- Page table of contents -->
                        <div class="sidetoc">
                            <nav class="pagetoc"></nav>
                        </div>

                        <h1 id="spam-checker-callbacks"><a class="header" href="#spam-checker-callbacks">Spam checker callbacks</a></h1>
<p>Spam checker callbacks allow module developers to implement spam mitigation actions for
Synapse instances. 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>
<p><em>Changed in Synapse v1.60.0: <code>synapse.module_api.NOT_SPAM</code> and <code>synapse.module_api.errors.Codes</code> can be returned by this callback. Returning a boolean or a string is now deprecated.</em> </p>
<pre><code class="language-python">async def check_event_for_spam(event: &quot;synapse.module_api.EventBase&quot;) -&gt; Union[&quot;synapse.module_api.NOT_SPAM&quot;, &quot;synapse.module_api.errors.Codes&quot;, str, bool]
</code></pre>
<p>Called when receiving an event from a client or via federation. The callback must return one of:</p>
<ul>
<li><code>synapse.module_api.NOT_SPAM</code>, to allow the operation. Other callbacks may still 
decide to reject it.</li>
<li><code>synapse.module_api.errors.Codes</code> to reject the operation with an error code. In case
of doubt, <code>synapse.module_api.errors.Codes.FORBIDDEN</code> is a good error code.</li>
<li>(deprecated) a non-<code>Codes</code> <code>str</code> to reject the operation and specify an error message. Note that clients
typically will not localize the error message to the user's preferred locale.</li>
<li>(deprecated) <code>False</code>, which is the same as returning <code>synapse.module_api.NOT_SPAM</code>.</li>
<li>(deprecated) <code>True</code>, which is the same as returning <code>synapse.module_api.errors.Codes.FORBIDDEN</code>.</li>
</ul>
<p>If multiple modules implement this callback, they will be considered in order. If a
callback returns <code>synapse.module_api.NOT_SPAM</code>, Synapse falls through to the next one.
The value of the first callback that does not return <code>synapse.module_api.NOT_SPAM</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>
<p><em>Changed in Synapse v1.61.0: <code>synapse.module_api.NOT_SPAM</code> and <code>synapse.module_api.errors.Codes</code> can be returned by this callback. Returning a boolean is now deprecated.</em> </p>
<pre><code class="language-python">async def user_may_join_room(user: str, room: str, is_invited: bool) -&gt; Union[&quot;synapse.module_api.NOT_SPAM&quot;, &quot;synapse.module_api.errors.Codes&quot;, bool]
</code></pre>
<p>Called when a user is trying to join a 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>The callback must return one of:</p>
<ul>
<li><code>synapse.module_api.NOT_SPAM</code>, to allow the operation. Other callbacks may still 
decide to reject it.</li>
<li><code>synapse.module_api.errors.Codes</code> to reject the operation with an error code. In case
of doubt, <code>synapse.module_api.errors.Codes.FORBIDDEN</code> is a good error code.</li>
<li>(deprecated) <code>False</code>, which is the same as returning <code>synapse.module_api.NOT_SPAM</code>.</li>
<li>(deprecated) <code>True</code>, which is the same as returning <code>synapse.module_api.errors.Codes.FORBIDDEN</code>.</li>
</ul>
<p>If multiple modules implement this callback, they will be considered in order. If a
callback returns <code>synapse.module_api.NOT_SPAM</code>, Synapse falls through to the next one.
The value of the first callback that does not return <code>synapse.module_api.NOT_SPAM</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>
<p><em>Changed in Synapse v1.62.0: <code>synapse.module_api.NOT_SPAM</code> and <code>synapse.module_api.errors.Codes</code> can be returned by this callback. Returning a boolean is now deprecated.</em> </p>
<pre><code class="language-python">async def user_may_invite(inviter: str, invitee: str, room_id: str) -&gt; Union[&quot;synapse.module_api.NOT_SPAM&quot;, &quot;synapse.module_api.errors.Codes&quot;, bool]
</code></pre>
<p>Called when processing an invitation. Both inviter and invitee are
represented by their Matrix user ID (e.g. <code>@alice:example.com</code>).</p>
<p>The callback must return one of:</p>
<ul>
<li>
<p><code>synapse.module_api.NOT_SPAM</code>, to allow the operation. Other callbacks may still 
decide to reject it.</p>
</li>
<li>
<p><code>synapse.module_api.errors.Codes</code> to reject the operation with an error code. In case
of doubt, <code>synapse.module_api.errors.Codes.FORBIDDEN</code> is a good error code.</p>
</li>
<li>
<p>(deprecated) <code>False</code>, which is the same as returning <code>synapse.module_api.NOT_SPAM</code>.</p>
</li>
<li>
<p>(deprecated) <code>True</code>, which is the same as returning <code>synapse.module_api.errors.Codes.FORBIDDEN</code>.</p>
</li>
</ul>
<p>If multiple modules implement this callback, they will be considered in order. If a
callback returns <code>synapse.module_api.NOT_SPAM</code>, Synapse falls through to the next one.
The value of the first callback that does not return <code>synapse.module_api.NOT_SPAM</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>
<p><em>Changed in Synapse v1.62.0: <code>synapse.module_api.NOT_SPAM</code> and <code>synapse.module_api.errors.Codes</code> can be returned by this callback. Returning a boolean is now deprecated.</em> </p>
<pre><code class="language-python">async def user_may_send_3pid_invite(
    inviter: str,
    medium: str,
    address: str,
    room_id: str,
) -&gt; Union[&quot;synapse.module_api.NOT_SPAM&quot;, &quot;synapse.module_api.errors.Codes&quot;, 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). </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. &quot;email&quot;) 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(
    &quot;@bob:example.com&quot;,  # The inviter's user ID
    &quot;email&quot;,  # The medium of the 3PID to invite
    &quot;alice@example.com&quot;,  # The address of the 3PID to invite
    &quot;!some_room:example.com&quot;,  # 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>The callback must return one of:</p>
<ul>
<li>
<p><code>synapse.module_api.NOT_SPAM</code>, to allow the operation. Other callbacks may still 
decide to reject it.</p>
</li>
<li>
<p><code>synapse.module_api.errors.Codes</code> to reject the operation with an error code. In case
of doubt, <code>synapse.module_api.errors.Codes.FORBIDDEN</code> is a good error code.</p>
</li>
<li>
<p>(deprecated) <code>False</code>, which is the same as returning <code>synapse.module_api.NOT_SPAM</code>.</p>
</li>
<li>
<p>(deprecated) <code>True</code>, which is the same as returning <code>synapse.module_api.errors.Codes.FORBIDDEN</code>.</p>
</li>
</ul>
<p>If multiple modules implement this callback, they will be considered in order. If a
callback returns <code>synapse.module_api.NOT_SPAM</code>, Synapse falls through to the next one.
The value of the first callback that does not return <code>synapse.module_api.NOT_SPAM</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>
<p><em>Changed in Synapse v1.62.0: <code>synapse.module_api.NOT_SPAM</code> and <code>synapse.module_api.errors.Codes</code> can be returned by this callback. Returning a boolean is now deprecated.</em> </p>
<pre><code class="language-python">async def user_may_create_room(user_id: str) -&gt; Union[&quot;synapse.module_api.NOT_SPAM&quot;, &quot;synapse.module_api.errors.Codes&quot;, bool]
</code></pre>
<p>Called when processing a room creation request.</p>
<p>The callback must return one of:</p>
<ul>
<li>
<p><code>synapse.module_api.NOT_SPAM</code>, to allow the operation. Other callbacks may still 
decide to reject it.</p>
</li>
<li>
<p><code>synapse.module_api.errors.Codes</code> to reject the operation with an error code. In case
of doubt, <code>synapse.module_api.errors.Codes.FORBIDDEN</code> is a good error code.</p>
</li>
<li>
<p>(deprecated) <code>False</code>, which is the same as returning <code>synapse.module_api.NOT_SPAM</code>.</p>
</li>
<li>
<p>(deprecated) <code>True</code>, which is the same as returning <code>synapse.module_api.errors.Codes.FORBIDDEN</code>.</p>
</li>
</ul>
<p>If multiple modules implement this callback, they will be considered in order. If a
callback returns <code>synapse.module_api.NOT_SPAM</code>, Synapse falls through to the next one.
The value of the first callback that does not return <code>synapse.module_api.NOT_SPAM</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>
<p><em>Changed in Synapse v1.62.0: <code>synapse.module_api.NOT_SPAM</code> and <code>synapse.module_api.errors.Codes</code> can be returned by this callback. Returning a boolean is now deprecated.</em> </p>
<pre><code class="language-python">async def user_may_create_room_alias(user_id: str, room_alias: &quot;synapse.module_api.RoomAlias&quot;) -&gt; Union[&quot;synapse.module_api.NOT_SPAM&quot;, &quot;synapse.module_api.errors.Codes&quot;, bool]
</code></pre>
<p>Called when trying to associate an alias with an existing room.</p>
<p>The callback must return one of:</p>
<ul>
<li>
<p><code>synapse.module_api.NOT_SPAM</code>, to allow the operation. Other callbacks may still 
decide to reject it.</p>
</li>
<li>
<p><code>synapse.module_api.errors.Codes</code> to reject the operation with an error code. In case
of doubt, <code>synapse.module_api.errors.Codes.FORBIDDEN</code> is a good error code.</p>
</li>
<li>
<p>(deprecated) <code>False</code>, which is the same as returning <code>synapse.module_api.NOT_SPAM</code>.</p>
</li>
<li>
<p>(deprecated) <code>True</code>, which is the same as returning <code>synapse.module_api.errors.Codes.FORBIDDEN</code>.</p>
</li>
</ul>
<p>If multiple modules implement this callback, they will be considered in order. If a
callback returns <code>synapse.module_api.NOT_SPAM</code>, Synapse falls through to the next one.
The value of the first callback that does not return <code>synapse.module_api.NOT_SPAM</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>
<p><em>Changed in Synapse v1.62.0: <code>synapse.module_api.NOT_SPAM</code> and <code>synapse.module_api.errors.Codes</code> can be returned by this callback. Returning a boolean is now deprecated.</em> </p>
<pre><code class="language-python">async def user_may_publish_room(user_id: str, room_id: str) -&gt; Union[&quot;synapse.module_api.NOT_SPAM&quot;, &quot;synapse.module_api.errors.Codes&quot;, bool]
</code></pre>
<p>Called when trying to publish a room to the homeserver's public rooms directory.</p>
<p>The callback must return one of:</p>
<ul>
<li>
<p><code>synapse.module_api.NOT_SPAM</code>, to allow the operation. Other callbacks may still 
decide to reject it.</p>
</li>
<li>
<p><code>synapse.module_api.errors.Codes</code> to reject the operation with an error code. In case
of doubt, <code>synapse.module_api.errors.Codes.FORBIDDEN</code> is a good error code.</p>
</li>
<li>
<p>(deprecated) <code>False</code>, which is the same as returning <code>synapse.module_api.NOT_SPAM</code>.</p>
</li>
<li>
<p>(deprecated) <code>True</code>, which is the same as returning <code>synapse.module_api.errors.Codes.FORBIDDEN</code>.</p>
</li>
</ul>
<p>If multiple modules implement this callback, they will be considered in order. If a
callback returns <code>synapse.module_api.NOT_SPAM</code>, Synapse falls through to the next one.
The value of the first callback that does not return <code>synapse.module_api.NOT_SPAM</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: synapse.module_api.UserProfile) -&gt; 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 should be excluded from user directory 
searches. Return <code>True</code> to indicate that the user is spammy and exclude them from 
search results; otherwise return <code>False</code>.</p>
<p>The profile is represented as a dictionary with the following keys:</p>
<ul>
<li><code>user_id: str</code>. The Matrix ID for this user.</li>
<li><code>display_name: Optional[str]</code>. The user's display name, or <code>None</code> if this user
has not set a display name.</li>
<li><code>avatar_url: Optional[str]</code>. The <code>mxc://</code> URL to the user's avatar, or <code>None</code>
if this user has not set an 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,
) -&gt; &quot;synapse.spam_checker_api.RegistrationBehaviour&quot;
</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>
<p><em>Changed in Synapse v1.62.0: <code>synapse.module_api.NOT_SPAM</code> and <code>synapse.module_api.errors.Codes</code> can be returned by this callback. Returning a boolean is now deprecated.</em> </p>
<pre><code class="language-python">async def check_media_file_for_spam(
    file_wrapper: &quot;synapse.rest.media.v1.media_storage.ReadableFileWrapper&quot;,
    file_info: &quot;synapse.rest.media.v1._base.FileInfo&quot;,
) -&gt; Union[&quot;synapse.module_api.NOT_SPAM&quot;, &quot;synapse.module_api.errors.Codes&quot;, bool]
</code></pre>
<p>Called when storing a local or remote file.</p>
<p>The callback must return one of:</p>
<ul>
<li>
<p><code>synapse.module_api.NOT_SPAM</code>, to allow the operation. Other callbacks may still 
decide to reject it.</p>
</li>
<li>
<p><code>synapse.module_api.errors.Codes</code> to reject the operation with an error code. In case
of doubt, <code>synapse.module_api.errors.Codes.FORBIDDEN</code> is a good error code.</p>
</li>
<li>
<p>(deprecated) <code>False</code>, which is the same as returning <code>synapse.module_api.NOT_SPAM</code>.</p>
</li>
<li>
<p>(deprecated) <code>True</code>, which is the same as returning <code>synapse.module_api.errors.Codes.FORBIDDEN</code>.</p>
</li>
</ul>
<p>If multiple modules implement this callback, they will be considered in order. If a
callback returns <code>synapse.module_api.NOT_SPAM</code>, Synapse falls through to the next one.
The value of the first callback that does not return <code>synapse.module_api.NOT_SPAM</code> will
be used. If this happens, Synapse will not call any of the subsequent implementations of
this callback.</p>
<h3 id="should_drop_federated_event"><a class="header" href="#should_drop_federated_event"><code>should_drop_federated_event</code></a></h3>
<p><em>First introduced in Synapse v1.60.0</em></p>
<pre><code class="language-python">async def should_drop_federated_event(event: &quot;synapse.events.EventBase&quot;) -&gt; bool
</code></pre>
<p>Called when checking whether a remote server can federate an event with us. <strong>Returning
<code>True</code> from this function will silently drop a federated event and split-brain our view
of a room's DAG, and thus you shouldn't use this callback unless you know what you are
doing.</strong></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(&quot;evil_users&quot;) or []

    def render_GET(self, request: Request):
        user = request.args.get(b&quot;user&quot;)[0].decode()
        request.setHeader(b&quot;Content-Type&quot;, b&quot;application/json&quot;)
        return json.dumps({&quot;evil&quot;: user in self.evil_users}).encode()


class ListSpamChecker:
    def __init__(self, config: dict, api: ModuleApi):
        self.api = api
        self.evil_users = config.get(&quot;evil_users&quot;) or []

        self.api.register_spam_checker_callbacks(
            check_event_for_spam=self.check_event_for_spam,
        )

        self.api.register_web_resource(
            path=&quot;/_synapse/client/list_spam_checker/is_evil&quot;,
            resource=IsUserEvilResource(config),
        )

    async def check_event_for_spam(self, event: &quot;synapse.events.EventBase&quot;) -&gt; Union[Literal[&quot;NOT_SPAM&quot;], Codes]:
        if event.sender in self.evil_users:
          return Codes.FORBIDDEN
        else:
          return synapse.module_api.NOT_SPAM
</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>
    </body>
</html>