Move callback-related code from AccountData to its own class

Move callback-related code from the PasswordAuthProvider to its own class
Move callback-related code from the BackgroundUpdater to its own class
2023-03-09 16:50:31 +00:00 · 2023-03-09 16:50:31 +00:00 · 2023-03-09 16:50:31 +00:00 · 2023-03-09 16:50:31 +00:00 · 2023-03-09 16:50:31 +00:00 · 2023-03-09 16:50:31 +00:00
130 changed files with 2541 additions and 2065 deletions
--- a/.ci/scripts/calculate_jobs.py
+++ b/.ci/scripts/calculate_jobs.py
@@ -109,11 +109,26 @@ sytest_tests = [
        "postgres": "multi-postgres",
        "workers": "workers",
    },
+    {
+        "sytest-tag": "focal",
+        "postgres": "multi-postgres",
+        "workers": "workers",
+        "reactor": "asyncio",
+    },
 ]

 if not IS_PR:
    sytest_tests.extend(
        [
+            {
+                "sytest-tag": "focal",
+                "reactor": "asyncio",
+            },
+            {
+                "sytest-tag": "focal",
+                "postgres": "postgres",
+                "reactor": "asyncio",
+            },
            {
                "sytest-tag": "testing",
                "postgres": "postgres",
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -156,7 +156,8 @@ jobs:
        # We pin to a specific commit for paranoia's sake.
        uses: dtolnay/rust-toolchain@e12eda571dc9a5ee5d58eecf4738ec291c66f295
        with:
-          toolchain: 1.58.1
+          # We use nightly so that it correctly groups together imports
+          toolchain: nightly-2022-12-01
          components: rustfmt
      - uses: Swatinem/rust-cache@v2

@@ -368,6 +369,7 @@ jobs:
        SYTEST_BRANCH: ${{ github.head_ref }}
        POSTGRES: ${{ matrix.job.postgres && 1}}
        MULTI_POSTGRES: ${{ (matrix.job.postgres == 'multi-postgres') && 1}}
+        ASYNCIO_REACTOR: ${{ (matrix.job.reactor == 'asyncio') && 1 }}
        WORKERS: ${{ matrix.job.workers && 1 }}
        BLACKLIST: ${{ matrix.job.workers && 'synapse-blacklist-with-workers' }}
        TOP: ${{ github.workspace }}
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,3 +1,100 @@
+Synapse 1.79.0rc1 (2023-03-07)
+==============================
+
+Features
+--------
+
+- Add two new Third Party Rules module API callbacks: [`on_add_user_third_party_identifier`](https://matrix-org.github.io/synapse/v1.79/modules/third_party_rules_callbacks.html#on_add_user_third_party_identifier) and [`on_remove_user_third_party_identifier`](https://matrix-org.github.io/synapse/v1.79/modules/third_party_rules_callbacks.html#on_remove_user_third_party_identifier). ([\#15044](https://github.com/matrix-org/synapse/issues/15044))
+- Experimental support for [MSC3967](https://github.com/matrix-org/matrix-spec-proposals/pull/3967) to not require UIA for setting up cross-signing on first use. ([\#15077](https://github.com/matrix-org/synapse/issues/15077))
+- Add media information to the command line [user data export tool](https://matrix-org.github.io/synapse/v1.79/usage/administration/admin_faq.html#how-can-i-export-user-data). ([\#15107](https://github.com/matrix-org/synapse/issues/15107))
+- Add an [admin API](https://matrix-org.github.io/synapse/latest/usage/administration/admin_api/index.html) to delete a [specific event report](https://spec.matrix.org/v1.6/client-server-api/#reporting-content). ([\#15116](https://github.com/matrix-org/synapse/issues/15116))
+- Add support for knocking to workers. ([\#15133](https://github.com/matrix-org/synapse/issues/15133))
+- Allow use of the `/filter` Client-Server APIs on workers. ([\#15134](https://github.com/matrix-org/synapse/issues/15134))
+- Update support for [MSC2677](https://github.com/matrix-org/matrix-spec-proposals/pull/2677): remove support for server-side aggregation of reactions. ([\#15172](https://github.com/matrix-org/synapse/issues/15172))
+- Stabilise support for [MSC3758](https://github.com/matrix-org/matrix-spec-proposals/pull/3758): `event_property_is` push condition. ([\#15185](https://github.com/matrix-org/synapse/issues/15185))
+
+
+Bugfixes
+--------
+
+- Fix a bug introduced in Synapse 1.75 that caused experimental support for deleting account data to raise an internal server error while using an account data writer worker. ([\#14869](https://github.com/matrix-org/synapse/issues/14869))
+- Fix a long-standing bug where Synapse handled an unspecced field on push rules. ([\#15088](https://github.com/matrix-org/synapse/issues/15088))
+- Fix a long-standing bug where a URL preview would break if the discovered oEmbed failed to download. ([\#15092](https://github.com/matrix-org/synapse/issues/15092))
+- Fix a long-standing bug where an initial sync would not respond to changes to the list of ignored users if there was an initial sync cached. ([\#15163](https://github.com/matrix-org/synapse/issues/15163))
+- Add the `transaction_id` in the events included in many endpoints' responses. ([\#15174](https://github.com/matrix-org/synapse/issues/15174))
+- Fix a bug introduced in Synapse 1.78.0 where requests to claim dehydrated devices would fail with a `405` error. ([\#15180](https://github.com/matrix-org/synapse/issues/15180))
+- Stop applying edits when bundling aggregations, per [MSC3925](https://github.com/matrix-org/matrix-spec-proposals/pull/3925). ([\#15193](https://github.com/matrix-org/synapse/issues/15193))
+- Fix a long-standing bug where the user directory search was not case-insensitive for accented characters. ([\#15143](https://github.com/matrix-org/synapse/issues/15143))
+
+
+Updates to the Docker image
+---------------------------
+
+- Improve startup logging in the with-workers Docker image. ([\#15186](https://github.com/matrix-org/synapse/issues/15186))
+
+
+Improved Documentation
+----------------------
+
+- Document how to use caches in a module. ([\#14026](https://github.com/matrix-org/synapse/issues/14026))
+- Clarify which worker processes the ThirdPartyRules' [`on_new_event`](https://matrix-org.github.io/synapse/v1.78/modules/third_party_rules_callbacks.html#on_new_event) module API callback runs on. ([\#15071](https://github.com/matrix-org/synapse/issues/15071))
+- Document using [Shibboleth](https://www.shibboleth.net/) as an OpenID Provider. ([\#15112](https://github.com/matrix-org/synapse/issues/15112))
+- Correct reference to `federation_verify_certificates` in configuration documentation. ([\#15139](https://github.com/matrix-org/synapse/issues/15139))
+- Correct small documentation errors in some `MatrixFederationHttpClient` methods. ([\#15148](https://github.com/matrix-org/synapse/issues/15148))
+- Correct the description of the behavior of `registration_shared_secret_path` on startup. ([\#15168](https://github.com/matrix-org/synapse/issues/15168))
+
+
+Deprecations and Removals
+-------------------------
+
+- Deprecate the `on_threepid_bind` module callback, to be replaced by [`on_add_user_third_party_identifier`](https://matrix-org.github.io/synapse/v1.79/modules/third_party_rules_callbacks.html#on_add_user_third_party_identifier). See [upgrade notes](https://github.com/matrix-org/synapse/blob/release-v1.79/docs/upgrade.md#upgrading-to-v1790). ([\#15044]
+- Remove the unspecced `room_alias` field from the [`/createRoom`](https://spec.matrix.org/v1.6/client-server-api/#post_matrixclientv3createroom) response. ([\#15093](https://github.com/matrix-org/synapse/issues/15093))
+- Remove the unspecced `PUT` on the `/knock/{roomIdOrAlias}` endpoint. ([\#15189](https://github.com/matrix-org/synapse/issues/15189))
+- Remove the undocumented and unspecced `type` parameter to the `/thumbnail` endpoint. ([\#15137](https://github.com/matrix-org/synapse/issues/15137))
+- Remove unspecced and buggy `PUT` method on the unstable `/rooms/<room_id>/batch_send` endpoint. ([\#15199](https://github.com/matrix-org/synapse/issues/15199))
+
+
+Internal Changes
+----------------
+
+- Run the integration test suites with the asyncio reactor enabled in CI. ([\#14101](https://github.com/matrix-org/synapse/issues/14101))
+- Batch up storing state groups when creating a new room. ([\#14918](https://github.com/matrix-org/synapse/issues/14918))
+- Update [MSC3952](https://github.com/matrix-org/matrix-spec-proposals/pull/3952) support based on changes to the MSC. ([\#15051](https://github.com/matrix-org/synapse/issues/15051))
+- Refactor writing json data in `FileExfiltrationWriter`. ([\#15095](https://github.com/matrix-org/synapse/issues/15095))
+- Tighten the login ratelimit defaults. ([\#15135](https://github.com/matrix-org/synapse/issues/15135))
+- Fix a typo in an experimental config setting. ([\#15138](https://github.com/matrix-org/synapse/issues/15138))
+- Refactor the media modules. ([\#15146](https://github.com/matrix-org/synapse/issues/15146), [\#15175](https://github.com/matrix-org/synapse/issues/15175))
+- Improve type hints. ([\#15164](https://github.com/matrix-org/synapse/issues/15164))
+- Move `get_event_report` and `get_event_reports_paginate` from `RoomStore` to `RoomWorkerStore`. ([\#15165](https://github.com/matrix-org/synapse/issues/15165))
+- Remove dangling reference to being a reference implementation in docstring. ([\#15167](https://github.com/matrix-org/synapse/issues/15167))
+- Add an option to force a rebuild of the "editable" complement image. ([\#15184](https://github.com/matrix-org/synapse/issues/15184))
+- Use nightly rustfmt in CI. ([\#15188](https://github.com/matrix-org/synapse/issues/15188))
+- Add a `get_next_txn` method to `StreamIdGenerator` to match `MultiWriterIdGenerator`. ([\#15191](https://github.com/matrix-org/synapse/issues/15191))
+- Combine `AbstractStreamIdTracker` and `AbstractStreamIdGenerator`. ([\#15192](https://github.com/matrix-org/synapse/issues/15192))
+- Automatically fix errors with `ruff`. ([\#15194](https://github.com/matrix-org/synapse/issues/15194))
+- Refactor database transaction for query users' devices to reduce database pool contention. ([\#15215](https://github.com/matrix-org/synapse/issues/15215))
+- Correct `test_icu_word_boundary_punctuation` so that it passes with the ICU versions available in Alpine and macOS. ([\#15177](https://github.com/matrix-org/synapse/issues/15177))
+
+<details><summary>Locked dependency updates</summary>
+
+  - Bump actions/checkout from 2 to 3. ([\#15155](https://github.com/matrix-org/synapse/issues/15155))
+  - Bump black from 22.12.0 to 23.1.0. ([\#15103](https://github.com/matrix-org/synapse/issues/15103))
+  - Bump dawidd6/action-download-artifact from 2.25.0 to 2.26.0. ([\#15152](https://github.com/matrix-org/synapse/issues/15152))
+  - Bump docker/login-action from 1 to 2. ([\#15154](https://github.com/matrix-org/synapse/issues/15154))
+  - Bump matrix-org/backend-meta from 1 to 2. ([\#15156](https://github.com/matrix-org/synapse/issues/15156))
+  - Bump ruff from 0.0.237 to 0.0.252. ([\#15159](https://github.com/matrix-org/synapse/issues/15159))
+  - Bump serde_json from 1.0.93 to 1.0.94. ([\#15214](https://github.com/matrix-org/synapse/issues/15214))
+  - Bump types-commonmark from 0.9.2.1 to 0.9.2.2. ([\#15209](https://github.com/matrix-org/synapse/issues/15209))
+  - Bump types-opentracing from 2.4.10.1 to 2.4.10.3. ([\#15158](https://github.com/matrix-org/synapse/issues/15158))
+  - Bump types-pillow from 9.4.0.13 to 9.4.0.17. ([\#15211](https://github.com/matrix-org/synapse/issues/15211))
+  - Bump types-psycopg2 from 2.9.21.4 to 2.9.21.8. ([\#15210](https://github.com/matrix-org/synapse/issues/15210))
+  - Bump types-pyopenssl from 22.1.0.2 to 23.0.0.4. ([\#15213](https://github.com/matrix-org/synapse/issues/15213))
+  - Bump types-setuptools from 67.3.0.1 to 67.4.0.3. ([\#15160](https://github.com/matrix-org/synapse/issues/15160))
+  - Bump types-setuptools from 67.4.0.3 to 67.5.0.0. ([\#15212](https://github.com/matrix-org/synapse/issues/15212))
+  - Bump typing-extensions from 4.4.0 to 4.5.0. ([\#15157](https://github.com/matrix-org/synapse/issues/15157))
+</details>
+
+
 Synapse 1.78.0 (2023-02-28)
 ===========================

--- a/Cargo.lock
+++ b/Cargo.lock
@@ -343,9 +343,9 @@ dependencies = [

 [[package]]
 name = "serde_json"
-version = "1.0.93"
+version = "1.0.94"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cad406b69c91885b5107daf2c29572f6c8cdb3c66826821e286c533490c0bc76"
+checksum = "1c533a59c9d8a93a09c6ab31f0fd5e5f4dd1b8fc9434804029839884765d04ea"
 dependencies = [
 "itoa",
 "ryu",
--- a/changelog.d/14026.doc
+++ b/changelog.d/14026.doc
@@ -1 +0,0 @@
-Document how to use caches in a module.
--- a/changelog.d/14918.misc
+++ b/changelog.d/14918.misc
@@ -1 +0,0 @@
-Batch up storing state groups when creating a new room.
--- a/changelog.d/15044.feature
+++ b/changelog.d/15044.feature
@@ -1 +0,0 @@
-Add two new Third Party Rules module API callbacks: [`on_add_user_third_party_identifier`](https://matrix-org.github.io/synapse/v1.79/modules/third_party_rules_callbacks.html#on_add_user_third_party_identifier) and [`on_remove_user_third_party_identifier`](https://matrix-org.github.io/synapse/v1.79/modules/third_party_rules_callbacks.html#on_remove_user_third_party_identifier).
--- a/changelog.d/15071.doc
+++ b/changelog.d/15071.doc
@@ -1 +0,0 @@
-Clarify which worker processes the ThirdPartyRules' [`on_new_event`](https://matrix-org.github.io/synapse/v1.78/modules/third_party_rules_callbacks.html#on_new_event) module API callback runs on.
--- a/changelog.d/15088.bugfix
+++ b/changelog.d/15088.bugfix
@@ -1 +0,0 @@
-Fix a long-standing bug where Synapse handled an unspecced field on push rules.
--- a/changelog.d/15092.bugfix
+++ b/changelog.d/15092.bugfix
@@ -1 +0,0 @@
-Fix a long-standing bug where a URL preview would break if the discovered oEmbed failed to download.
--- a/changelog.d/15093.bugfix
+++ b/changelog.d/15093.bugfix
@@ -1 +0,0 @@
-Remove the unspecced `room_alias` field from the [`/createRoom`](https://spec.matrix.org/v1.6/client-server-api/#post_matrixclientv3createroom) response.
--- a/changelog.d/15095.misc
+++ b/changelog.d/15095.misc
@@ -1 +0,0 @@
-Refactor writing json data in `FileExfiltrationWriter`.
--- a/changelog.d/15103.misc
+++ b/changelog.d/15103.misc
@@ -1 +0,0 @@
-Bump black from 22.12.0 to 23.1.0.
--- a/changelog.d/15107.feature
+++ b/changelog.d/15107.feature
@@ -1 +0,0 @@
-Add media information to the command line [user data export tool](https://matrix-org.github.io/synapse/v1.79/usage/administration/admin_faq.html#how-can-i-export-user-data).
--- a/changelog.d/15112.doc
+++ b/changelog.d/15112.doc
@@ -1 +0,0 @@
-Document using [Shibboleth](https://www.shibboleth.net/) as an OpenID Provider.
--- a/changelog.d/15116.feature
+++ b/changelog.d/15116.feature
@@ -1 +0,0 @@
-Add an [admin API](https://matrix-org.github.io/synapse/latest/usage/administration/admin_api/index.html) to delete a [specific event report](https://spec.matrix.org/v1.6/client-server-api/#reporting-content).
--- a/changelog.d/15134.feature
+++ b/changelog.d/15134.feature
@@ -1 +0,0 @@
-Allow use of the `/filter` Client-Server APIs on workers.
--- a/changelog.d/15135.misc
+++ b/changelog.d/15135.misc
@@ -1 +0,0 @@
-Tighten the login ratelimit defaults.
--- a/changelog.d/15137.removal
+++ b/changelog.d/15137.removal
@@ -1 +0,0 @@
-Remove the undocumented and unspecced `type` parameter to the `/thumbnail` endpoint.
--- a/changelog.d/15138.misc
+++ b/changelog.d/15138.misc
@@ -1 +0,0 @@
-Fix a typo in an experimental config setting.
--- a/changelog.d/15139.doc
+++ b/changelog.d/15139.doc
@@ -1 +0,0 @@
-Correct reference to `federation_verify_certificates` in configuration documentation.
--- a/changelog.d/15143.misc
+++ b/changelog.d/15143.misc
@@ -1 +0,0 @@
-Fix a long-standing bug where the user directory search was not case-insensitive for accented characters.
--- a/changelog.d/15146.misc
+++ b/changelog.d/15146.misc
@@ -1 +0,0 @@
-Refactor the media modules.
--- a/changelog.d/15148.doc
+++ b/changelog.d/15148.doc
@@ -1 +0,0 @@
-Correct small documentation errors in some `MatrixFederationHttpClient` methods.
--- a/changelog.d/15152.misc
+++ b/changelog.d/15152.misc
@@ -1 +0,0 @@
-Bump dawidd6/action-download-artifact from 2.25.0 to 2.26.0.
--- a/changelog.d/15154.misc
+++ b/changelog.d/15154.misc
@@ -1 +0,0 @@
-Bump docker/login-action from 1 to 2.
--- a/changelog.d/15155.misc
+++ b/changelog.d/15155.misc
@@ -1 +0,0 @@
-Bump actions/checkout from 2 to 3.
--- a/changelog.d/15156.misc
+++ b/changelog.d/15156.misc
@@ -1 +0,0 @@
-Bump matrix-org/backend-meta from 1 to 2.
--- a/changelog.d/15157.misc
+++ b/changelog.d/15157.misc
@@ -1 +0,0 @@
-Bump typing-extensions from 4.4.0 to 4.5.0.
--- a/changelog.d/15158.misc
+++ b/changelog.d/15158.misc
@@ -1 +0,0 @@
-Bump types-opentracing from 2.4.10.1 to 2.4.10.3.
--- a/changelog.d/15159.misc
+++ b/changelog.d/15159.misc
@@ -1 +0,0 @@
-Bump ruff from 0.0.237 to 0.0.252.
--- a/changelog.d/15160.misc
+++ b/changelog.d/15160.misc
@@ -1 +0,0 @@
-Bump types-setuptools from 67.3.0.1 to 67.4.0.3.
--- a/changelog.d/15163.bugfix
+++ b/changelog.d/15163.bugfix
@@ -1 +0,0 @@
-Fix a long-standing bug where an initial sync would not respond to changes to the list of ignored users if there was an initial sync cached.
--- a/changelog.d/15164.misc
+++ b/changelog.d/15164.misc
@@ -1 +0,0 @@
-Improve type hints.
--- a/changelog.d/15167.misc
+++ b/changelog.d/15167.misc
@@ -1 +0,0 @@
-Remove dangling reference to being a reference implementation in docstring.
--- a/changelog.d/15168.doc
+++ b/changelog.d/15168.doc
@@ -1 +0,0 @@
-Correct the description of the behavior of `registration_shared_secret_path` on startup.
--- a/changelog.d/15172.feature
+++ b/changelog.d/15172.feature
@@ -1 +0,0 @@
-Remove support for server-side aggregation of reactions.
--- a/changelog.d/15175.misc
+++ b/changelog.d/15175.misc
@@ -1 +0,0 @@
-Refactor the media modules.
--- a/changelog.d/15187.feature
+++ b/changelog.d/15187.feature
@@ -0,0 +1 @@
+Stabilise support for [MSC3966](https://github.com/matrix-org/matrix-spec-proposals/pull/3966): `event_property_contains` push condition.
--- a/changelog.d/15190.bugfix
+++ b/changelog.d/15190.bugfix
@@ -0,0 +1 @@
+Implement [MSC3873](https://github.com/matrix-org/matrix-spec-proposals/pull/3873) to fix a long-standing bug where properties with dots were handled ambiguously in push rules.
--- a/changelog.d/15195.misc
+++ b/changelog.d/15195.misc
@@ -0,0 +1 @@
+Improve performance of creating and authenticating events.
--- a/changelog.d/15200.misc
+++ b/changelog.d/15200.misc
@@ -0,0 +1 @@
+Make the `HttpTransactionCache` use the `Requester` in addition of the just the `Request` to build the transaction key.
--- a/changelog.d/15223.doc
+++ b/changelog.d/15223.doc
@@ -0,0 +1 @@
+Add a missing endpoint to the workers documentation.
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,9 @@
+matrix-synapse-py3 (1.79.0~rc1) stable; urgency=medium
+
+  * New Synapse release 1.79.0rc1.
+
+ -- Synapse Packaging team <packages@matrix.org>  Tue, 07 Mar 2023 12:03:49 +0000
+
 matrix-synapse-py3 (1.78.0) stable; urgency=medium

  * New Synapse release 1.78.0.
--- a/docker/configure_workers_and_start.py
+++ b/docker/configure_workers_and_start.py
@@ -205,6 +205,7 @@ WORKERS_CONFIG: Dict[str, Dict[str, Any]] = {
            "^/_matrix/client/(api/v1|r0|v3|unstable)/rooms/.*/send",
            "^/_matrix/client/(api/v1|r0|v3|unstable)/rooms/.*/(join|invite|leave|ban|unban|kick)$",
            "^/_matrix/client/(api/v1|r0|v3|unstable)/join/",
+            "^/_matrix/client/(api/v1|r0|v3|unstable)/knock/",
            "^/_matrix/client/(api/v1|r0|v3|unstable)/profile/",
            "^/_matrix/client/(v1|unstable/org.matrix.msc2716)/rooms/.*/batch_send",
        ],
@@ -675,17 +676,21 @@ def main(args: List[str], environ: MutableMapping[str, str]) -> None:
    if not os.path.exists(config_path):
        log("Generating base homeserver config")
        generate_base_homeserver_config()
-
+    else:
+        log("Base homeserver config exists—not regenerating")
    # This script may be run multiple times (mostly by Complement, see note at top of file).
    # Don't re-configure workers in this instance.
    mark_filepath = "/conf/workers_have_been_configured"
    if not os.path.exists(mark_filepath):
        # Always regenerate all other config files
+        log("Generating worker config files")
        generate_worker_files(environ, config_path, data_dir)

        # Mark workers as being configured
        with open(mark_filepath, "w") as f:
            f.write("")
+    else:
+        log("Worker config exists—not regenerating")

    # Lifted right out of start.py
    jemallocpath = "/usr/lib/%s-linux-gnu/libjemalloc.so.2" % (platform.machine(),)
--- a/docs/workers.md
+++ b/docs/workers.md
@@ -231,6 +231,7 @@ information.
    ^/_matrix/client/(api/v1|r0|v3|unstable)/rooms/.*/event/
    ^/_matrix/client/(api/v1|r0|v3|unstable)/joined_rooms$
    ^/_matrix/client/v1/rooms/.*/timestamp_to_event$
+    ^/_matrix/client/(api/v1|r0|v3|unstable/.*)/rooms/.*/aliases
    ^/_matrix/client/(api/v1|r0|v3|unstable)/search$
    ^/_matrix/client/(r0|v3|unstable)/user/.*/filter(/|$)

@@ -252,6 +253,7 @@ information.
    ^/_matrix/client/(api/v1|r0|v3|unstable)/rooms/.*/state/
    ^/_matrix/client/(api/v1|r0|v3|unstable)/rooms/.*/(join|invite|leave|ban|unban|kick)$
    ^/_matrix/client/(api/v1|r0|v3|unstable)/join/
+    ^/_matrix/client/(api/v1|r0|v3|unstable)/knock/
    ^/_matrix/client/(api/v1|r0|v3|unstable)/profile/

    # Account data requests
--- a/poetry.lock
+++ b/poetry.lock
@@ -2575,54 +2575,14 @@ files = [

 [[package]]
 name = "types-commonmark"
-version = "0.9.2.1"
+version = "0.9.2.2"
 description = "Typing stubs for commonmark"
 category = "dev"
 optional = false
 python-versions = "*"
 files = [
-    {file = "types-commonmark-0.9.2.1.tar.gz", hash = "sha256:db8277e6aeb83429265eccece98a24954a9a502dde7bc7cf840a8741abd96b86"},
-    {file = "types_commonmark-0.9.2.1-py3-none-any.whl", hash = "sha256:9d5f500cb7eced801bde728137b0a10667bd853d328db641d03141f189e3aab4"},
-]
-
-[[package]]
-name = "types-cryptography"
-version = "3.3.15"
-description = "Typing stubs for cryptography"
-category = "dev"
-optional = false
-python-versions = "*"
-files = [
-    {file = "types-cryptography-3.3.15.tar.gz", hash = "sha256:a7983a75a7b88a18f88832008f0ef140b8d1097888ec1a0824ec8fb7e105273b"},
-    {file = "types_cryptography-3.3.15-py3-none-any.whl", hash = "sha256:d9b0dd5465d7898d400850e7f35e5518aa93a7e23d3e11757cd81b4777089046"},
-]
-
-[package.dependencies]
-types-enum34 = "*"
-types-ipaddress = "*"
-
-[[package]]
-name = "types-enum34"
-version = "1.1.8"
-description = "Typing stubs for enum34"
-category = "dev"
-optional = false
-python-versions = "*"
-files = [
-    {file = "types-enum34-1.1.8.tar.gz", hash = "sha256:6f9c769641d06d73a55e11c14d38ac76fcd37eb545ce79cebb6eec9d50a64110"},
-    {file = "types_enum34-1.1.8-py3-none-any.whl", hash = "sha256:05058c7a495f6bfaaca0be4aeac3cce5cdd80a2bad2aab01fd49a20bf4a0209d"},
-]
-
-[[package]]
-name = "types-ipaddress"
-version = "1.0.8"
-description = "Typing stubs for ipaddress"
-category = "dev"
-optional = false
-python-versions = "*"
-files = [
-    {file = "types-ipaddress-1.0.8.tar.gz", hash = "sha256:a03df3be5935e50ba03fa843daabff539a041a28e73e0fce2c5705bee54d3841"},
-    {file = "types_ipaddress-1.0.8-py3-none-any.whl", hash = "sha256:4933b74da157ba877b1a705d64f6fa7742745e9ffd65e51011f370c11ebedb55"},
+    {file = "types-commonmark-0.9.2.2.tar.gz", hash = "sha256:f3259350634c2ce68ae503398430482f7cf44e5cae3d344995e916fbf453b4be"},
+    {file = "types_commonmark-0.9.2.2-py3-none-any.whl", hash = "sha256:d3d878692615e7fbe47bf19ba67497837b135812d665012a3d42219c1f2c3a61"},
 ]

 [[package]]
@@ -2651,42 +2611,42 @@ files = [

 [[package]]
 name = "types-pillow"
-version = "9.4.0.13"
+version = "9.4.0.17"
 description = "Typing stubs for Pillow"
 category = "dev"
 optional = false
 python-versions = "*"
 files = [
-    {file = "types-Pillow-9.4.0.13.tar.gz", hash = "sha256:4510aa98a28947bf63f2b29edebbd11b7cff8647d90b867cec9b3674c0a8c321"},
-    {file = "types_Pillow-9.4.0.13-py3-none-any.whl", hash = "sha256:14a8a19021b8fe569a9fef9edc64a8d8a4aef340e38669d4fb3dc05cfd941130"},
+    {file = "types-Pillow-9.4.0.17.tar.gz", hash = "sha256:7f0e871d2d46fbb6bc7deca3e02dc552cf9c1e8b49deb9595509551be3954e49"},
+    {file = "types_Pillow-9.4.0.17-py3-none-any.whl", hash = "sha256:f8b848a05f17cb4d53d245c59bf560372b9778d4cfaf9705f6245009bf9f65f3"},
 ]

 [[package]]
 name = "types-psycopg2"
-version = "2.9.21.4"
+version = "2.9.21.8"
 description = "Typing stubs for psycopg2"
 category = "dev"
 optional = false
 python-versions = "*"
 files = [
-    {file = "types-psycopg2-2.9.21.4.tar.gz", hash = "sha256:d43dda166a70d073ddac40718e06539836b5844c99b58ef8d4489a8df2edf5c0"},
-    {file = "types_psycopg2-2.9.21.4-py3-none-any.whl", hash = "sha256:6a05dca0856996aa37d7abe436751803bf47ec006cabbefea092e057f23bc95d"},
+    {file = "types-psycopg2-2.9.21.8.tar.gz", hash = "sha256:b629440ffcfdebd742fab07f777ff69aefdd19394a138c18e921a1964c3cf5f6"},
+    {file = "types_psycopg2-2.9.21.8-py3-none-any.whl", hash = "sha256:e747fbec6e0e2502b625bc7686d13cc62fc170e8ae920e5ba27fac946778eeb9"},
 ]

 [[package]]
 name = "types-pyopenssl"
-version = "22.1.0.2"
+version = "23.0.0.4"
 description = "Typing stubs for pyOpenSSL"
 category = "dev"
 optional = false
 python-versions = "*"
 files = [
-    {file = "types-pyOpenSSL-22.1.0.2.tar.gz", hash = "sha256:7a350e29e55bc3ee4571f996b4b1c18c4e4098947db45f7485b016eaa35b44bc"},
-    {file = "types_pyOpenSSL-22.1.0.2-py3-none-any.whl", hash = "sha256:54606a6afb203eb261e0fca9b7f75fa6c24d5ff71e13903c162ffb951c2c64c6"},
+    {file = "types-pyOpenSSL-23.0.0.4.tar.gz", hash = "sha256:8b3550b6e19d51ce78aabd724b0d8ebd962081a5fce95e7f85a592dfcdbc16bf"},
+    {file = "types_pyOpenSSL-23.0.0.4-py3-none-any.whl", hash = "sha256:ad49e15bb8bb2f251b8fc24776f414d877629e44b1b049240063ab013b5a6a7d"},
 ]

 [package.dependencies]
-types-cryptography = "*"
+cryptography = ">=35.0.0"

 [[package]]
 name = "types-pyyaml"
@@ -2717,14 +2677,14 @@ types-urllib3 = "<1.27"

 [[package]]
 name = "types-setuptools"
-version = "67.4.0.3"
+version = "67.5.0.0"
 description = "Typing stubs for setuptools"
 category = "dev"
 optional = false
 python-versions = "*"
 files = [
-    {file = "types-setuptools-67.4.0.3.tar.gz", hash = "sha256:19e958dfdbf1c5a628e54c2a7ee84935051afb7278d0c1cdb08ac194757ee3b1"},
-    {file = "types_setuptools-67.4.0.3-py3-none-any.whl", hash = "sha256:3c83c3a6363dd3ddcdd054796705605f0fa8b8e5a39390e07a05e5f7af054978"},
+    {file = "types-setuptools-67.5.0.0.tar.gz", hash = "sha256:fa6f231eeb27e86b1d6e8260f73de300e91f99c205b9a5e21debd49f3726a849"},
+    {file = "types_setuptools-67.5.0.0-py3-none-any.whl", hash = "sha256:f7f4bf4ab777e88631d3a387bbfdd4d480a2a4693ca896130f8ef738370377b8"},
 ]

 [[package]]
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -89,7 +89,7 @@ manifest-path = "rust/Cargo.toml"

 [tool.poetry]
 name = "matrix-synapse"
-version = "1.78.0"
+version = "1.79.0rc1"
 description = "Homeserver for the Matrix decentralised comms protocol"
 authors = ["Matrix.org Team and Contributors <packages@matrix.org>"]
 license = "Apache-2.0"
--- a/rust/benches/evaluator.rs
+++ b/rust/benches/evaluator.rs
@@ -14,6 +14,7 @@

 #![feature(test)]
 use std::collections::BTreeSet;
+
 use synapse::push::{
    evaluator::PushRuleEvaluator, Condition, EventMatchCondition, FilteredPushRules, JsonValue,
    PushRules, SimpleJsonValue,
@@ -44,7 +45,6 @@ fn bench_match_exact(b: &mut Bencher) {
    let eval = PushRuleEvaluator::py_new(
        flattened_keys,
        false,
-        BTreeSet::new(),
        10,
        Some(0),
        Default::default(),
@@ -52,8 +52,6 @@ fn bench_match_exact(b: &mut Bencher) {
        true,
        vec![],
        false,
-        false,
-        false,
    )
    .unwrap();

@@ -92,7 +90,6 @@ fn bench_match_word(b: &mut Bencher) {
    let eval = PushRuleEvaluator::py_new(
        flattened_keys,
        false,
-        BTreeSet::new(),
        10,
        Some(0),
        Default::default(),
@@ -100,8 +97,6 @@ fn bench_match_word(b: &mut Bencher) {
        true,
        vec![],
        false,
-        false,
-        false,
    )
    .unwrap();

@@ -140,7 +135,6 @@ fn bench_match_word_miss(b: &mut Bencher) {
    let eval = PushRuleEvaluator::py_new(
        flattened_keys,
        false,
-        BTreeSet::new(),
        10,
        Some(0),
        Default::default(),
@@ -148,8 +142,6 @@ fn bench_match_word_miss(b: &mut Bencher) {
        true,
        vec![],
        false,
-        false,
-        false,
    )
    .unwrap();

@@ -188,7 +180,6 @@ fn bench_eval_message(b: &mut Bencher) {
    let eval = PushRuleEvaluator::py_new(
        flattened_keys,
        false,
-        BTreeSet::new(),
        10,
        Some(0),
        Default::default(),
@@ -196,8 +187,6 @@ fn bench_eval_message(b: &mut Bencher) {
        true,
        vec![],
        false,
-        false,
-        false,
    )
    .unwrap();

--- a/rust/src/push/base_rules.rs
+++ b/rust/src/push/base_rules.rs
@@ -21,13 +21,13 @@ use lazy_static::lazy_static;
 use serde_json::Value;

 use super::KnownCondition;
-use crate::push::PushRule;
 use crate::push::RelatedEventMatchTypeCondition;
 use crate::push::SetTweak;
 use crate::push::TweakValue;
-use crate::push::{Action, ExactEventMatchCondition, SimpleJsonValue};
+use crate::push::{Action, EventPropertyIsCondition, SimpleJsonValue};
 use crate::push::{Condition, EventMatchTypeCondition};
 use crate::push::{EventMatchCondition, EventMatchPatternType};
+use crate::push::{EventPropertyIsTypeCondition, PushRule};

 const HIGHLIGHT_ACTION: Action = Action::SetTweak(SetTweak {
    set_tweak: Cow::Borrowed("highlight"),
@@ -71,7 +71,7 @@ pub const BASE_APPEND_OVERRIDE_RULES: &[PushRule] = &[
        priority_class: 5,
        conditions: Cow::Borrowed(&[Condition::Known(KnownCondition::EventMatch(
            EventMatchCondition {
-                key: Cow::Borrowed("content.m.relates_to.rel_type"),
+                key: Cow::Borrowed("content.m\\.relates_to.rel_type"),
                pattern: Cow::Borrowed("m.replace"),
            },
        ))]),
@@ -144,7 +144,12 @@ pub const BASE_APPEND_OVERRIDE_RULES: &[PushRule] = &[
    PushRule {
        rule_id: Cow::Borrowed(".org.matrix.msc3952.is_user_mention"),
        priority_class: 5,
-        conditions: Cow::Borrowed(&[Condition::Known(KnownCondition::IsUserMention)]),
+        conditions: Cow::Borrowed(&[Condition::Known(
+            KnownCondition::ExactEventPropertyContainsType(EventPropertyIsTypeCondition {
+                key: Cow::Borrowed("content.org\\.matrix\\.msc3952\\.mentions.user_ids"),
+                value_type: Cow::Borrowed(&EventMatchPatternType::UserId),
+            }),
+        )]),
        actions: Cow::Borrowed(&[Action::Notify, HIGHLIGHT_ACTION, SOUND_ACTION]),
        default: true,
        default_enabled: true,
@@ -161,8 +166,8 @@ pub const BASE_APPEND_OVERRIDE_RULES: &[PushRule] = &[
        rule_id: Cow::Borrowed(".org.matrix.msc3952.is_room_mention"),
        priority_class: 5,
        conditions: Cow::Borrowed(&[
-            Condition::Known(KnownCondition::ExactEventMatch(ExactEventMatchCondition {
-                key: Cow::Borrowed("content.org.matrix.msc3952.mentions.room"),
+            Condition::Known(KnownCondition::EventPropertyIs(EventPropertyIsCondition {
+                key: Cow::Borrowed("content.org\\.matrix\\.msc3952\\.mentions.room"),
                value: Cow::Borrowed(&SimpleJsonValue::Bool(true)),
            })),
            Condition::Known(KnownCondition::SenderNotificationPermission {
--- a/rust/src/push/evaluator.rs
+++ b/rust/src/push/evaluator.rs
@@ -13,9 +13,8 @@
 // limitations under the License.

 use std::borrow::Cow;
-use std::collections::{BTreeMap, BTreeSet};
+use std::collections::BTreeMap;

-use crate::push::{EventMatchPatternType, JsonValue};
 use anyhow::{Context, Error};
 use lazy_static::lazy_static;
 use log::warn;
@@ -24,9 +23,10 @@ use regex::Regex;

 use super::{
    utils::{get_glob_matcher, get_localpart_from_id, GlobMatchType},
-    Action, Condition, ExactEventMatchCondition, FilteredPushRules, KnownCondition,
+    Action, Condition, EventPropertyIsCondition, FilteredPushRules, KnownCondition,
    SimpleJsonValue,
 };
+use crate::push::{EventMatchPatternType, JsonValue};

 lazy_static! {
    /// Used to parse the `is` clause in the room member count condition.
@@ -72,8 +72,6 @@ pub struct PushRuleEvaluator {

    /// True if the event has a mentions property and MSC3952 support is enabled.
    has_mentions: bool,
-    /// The user mentions that were part of the message.
-    user_mentions: BTreeSet<String>,

    /// The number of users in the room.
    room_member_count: u64,
@@ -98,12 +96,6 @@ pub struct PushRuleEvaluator {
    /// If MSC3931 (room version feature flags) is enabled. Usually controlled by the same
    /// flag as MSC1767 (extensible events core).
    msc3931_enabled: bool,
-
-    /// If MSC3758 (exact_event_match push rule condition) is enabled.
-    msc3758_exact_event_match: bool,
-
-    /// If MSC3966 (exact_event_property_contains push rule condition) is enabled.
-    msc3966_exact_event_property_contains: bool,
 }

 #[pymethods]
@@ -114,7 +106,6 @@ impl PushRuleEvaluator {
    pub fn py_new(
        flattened_keys: BTreeMap<String, JsonValue>,
        has_mentions: bool,
-        user_mentions: BTreeSet<String>,
        room_member_count: u64,
        sender_power_level: Option<i64>,
        notification_power_levels: BTreeMap<String, i64>,
@@ -122,8 +113,6 @@ impl PushRuleEvaluator {
        related_event_match_enabled: bool,
        room_version_feature_flags: Vec<String>,
        msc3931_enabled: bool,
-        msc3758_exact_event_match: bool,
-        msc3966_exact_event_property_contains: bool,
    ) -> Result<Self, Error> {
        let body = match flattened_keys.get("content.body") {
            Some(JsonValue::Value(SimpleJsonValue::Str(s))) => s.clone(),
@@ -134,7 +123,6 @@ impl PushRuleEvaluator {
            flattened_keys,
            body,
            has_mentions,
-            user_mentions,
            room_member_count,
            notification_power_levels,
            sender_power_level,
@@ -142,8 +130,6 @@ impl PushRuleEvaluator {
            related_event_match_enabled,
            room_version_feature_flags,
            msc3931_enabled,
-            msc3758_exact_event_match,
-            msc3966_exact_event_property_contains,
        })
    }

@@ -279,8 +265,8 @@ impl PushRuleEvaluator {

                self.match_event_match(&self.flattened_keys, &event_match.key, pattern)?
            }
-            KnownCondition::ExactEventMatch(exact_event_match) => {
-                self.match_exact_event_match(exact_event_match)?
+            KnownCondition::EventPropertyIs(event_property_is) => {
+                self.match_event_property_is(event_property_is)?
            }
            KnownCondition::RelatedEventMatch(event_match) => self.match_related_event_match(
                &event_match.rel_type.clone(),
@@ -310,15 +296,30 @@ impl PushRuleEvaluator {
                    Some(Cow::Borrowed(pattern)),
                )?
            }
-            KnownCondition::ExactEventPropertyContains(exact_event_match) => {
-                self.match_exact_event_property_contains(exact_event_match)?
-            }
-            KnownCondition::IsUserMention => {
-                if let Some(uid) = user_id {
-                    self.user_mentions.contains(uid)
+            KnownCondition::EventPropertyContains(event_property_is) => self
+                .match_event_property_contains(
+                    event_property_is.key.clone(),
+                    event_property_is.value.clone(),
+                )?,
+            KnownCondition::ExactEventPropertyContainsType(exact_event_match) => {
+                // The `pattern_type` can either be "user_id" or "user_localpart",
+                // either way if we don't have a `user_id` then the condition can't
+                // match.
+                let user_id = if let Some(user_id) = user_id {
+                    user_id
                } else {
-                    false
-                }
+                    return Ok(false);
+                };
+
+                let pattern = match &*exact_event_match.value_type {
+                    EventMatchPatternType::UserId => user_id,
+                    EventMatchPatternType::UserLocalpart => get_localpart_from_id(user_id)?,
+                };
+
+                self.match_event_property_contains(
+                    exact_event_match.key.clone(),
+                    Cow::Borrowed(&SimpleJsonValue::Str(pattern.to_string())),
+                )?
            }
            KnownCondition::ContainsDisplayName => {
                if let Some(dn) = display_name {
@@ -394,20 +395,15 @@ impl PushRuleEvaluator {
        compiled_pattern.is_match(haystack)
    }

-    /// Evaluates a `exact_event_match` condition. (MSC3758)
-    fn match_exact_event_match(
+    /// Evaluates a `event_property_is` condition.
+    fn match_event_property_is(
        &self,
-        exact_event_match: &ExactEventMatchCondition,
+        event_property_is: &EventPropertyIsCondition,
    ) -> Result<bool, Error> {
-        // First check if the feature is enabled.
-        if !self.msc3758_exact_event_match {
-            return Ok(false);
-        }
-
-        let value = &exact_event_match.value;
+        let value = &event_property_is.value;

        let haystack = if let Some(JsonValue::Value(haystack)) =
-            self.flattened_keys.get(&*exact_event_match.key)
+            self.flattened_keys.get(&*event_property_is.key)
        {
            haystack
        } else {
@@ -453,27 +449,19 @@ impl PushRuleEvaluator {
        }
    }

-    /// Evaluates a `exact_event_property_contains` condition. (MSC3758)
-    fn match_exact_event_property_contains(
+    /// Evaluates a `event_property_contains` condition.
+    fn match_event_property_contains(
        &self,
-        exact_event_match: &ExactEventMatchCondition,
+        key: Cow<str>,
+        value: Cow<SimpleJsonValue>,
    ) -> Result<bool, Error> {
-        // First check if the feature is enabled.
-        if !self.msc3966_exact_event_property_contains {
-            return Ok(false);
-        }
-
-        let value = &exact_event_match.value;
-
-        let haystack = if let Some(JsonValue::Array(haystack)) =
-            self.flattened_keys.get(&*exact_event_match.key)
-        {
+        let haystack = if let Some(JsonValue::Array(haystack)) = self.flattened_keys.get(&*key) {
            haystack
        } else {
            return Ok(false);
        };

-        Ok(haystack.contains(&**value))
+        Ok(haystack.contains(&value))
    }

    /// Match the member count against an 'is' condition
@@ -510,7 +498,6 @@ fn push_rule_evaluator() {
    let evaluator = PushRuleEvaluator::py_new(
        flattened_keys,
        false,
-        BTreeSet::new(),
        10,
        Some(0),
        BTreeMap::new(),
@@ -518,8 +505,6 @@ fn push_rule_evaluator() {
        true,
        vec![],
        true,
-        true,
-        true,
    )
    .unwrap();

@@ -542,7 +527,6 @@ fn test_requires_room_version_supports_condition() {
    let evaluator = PushRuleEvaluator::py_new(
        flattened_keys,
        false,
-        BTreeSet::new(),
        10,
        Some(0),
        BTreeMap::new(),
@@ -550,8 +534,6 @@ fn test_requires_room_version_supports_condition() {
        false,
        flags,
        true,
-        true,
-        true,
    )
    .unwrap();

--- a/rust/src/push/mod.rs
+++ b/rust/src/push/mod.rs
@@ -331,17 +331,16 @@ pub enum KnownCondition {
    // Identical to event_match but gives predefined patterns. Cannot be added by users.
    #[serde(skip_deserializing, rename = "event_match")]
    EventMatchType(EventMatchTypeCondition),
-    #[serde(rename = "com.beeper.msc3758.exact_event_match")]
-    ExactEventMatch(ExactEventMatchCondition),
+    EventPropertyIs(EventPropertyIsCondition),
    #[serde(rename = "im.nheko.msc3664.related_event_match")]
    RelatedEventMatch(RelatedEventMatchCondition),
    // Identical to related_event_match but gives predefined patterns. Cannot be added by users.
    #[serde(skip_deserializing, rename = "im.nheko.msc3664.related_event_match")]
    RelatedEventMatchType(RelatedEventMatchTypeCondition),
-    #[serde(rename = "org.matrix.msc3966.exact_event_property_contains")]
-    ExactEventPropertyContains(ExactEventMatchCondition),
-    #[serde(rename = "org.matrix.msc3952.is_user_mention")]
-    IsUserMention,
+    EventPropertyContains(EventPropertyIsCondition),
+    // Identical to exact_event_property_contains but gives predefined patterns. Cannot be added by users.
+    #[serde(skip_deserializing, rename = "event_property_contains")]
+    ExactEventPropertyContainsType(EventPropertyIsTypeCondition),
    ContainsDisplayName,
    RoomMemberCount {
        #[serde(skip_serializing_if = "Option::is_none")]
@@ -391,13 +390,22 @@ pub struct EventMatchTypeCondition {
    pub pattern_type: Cow<'static, EventMatchPatternType>,
 }

-/// The body of a [`Condition::ExactEventMatch`]
+/// The body of a [`Condition::EventPropertyIs`]
 #[derive(Serialize, Deserialize, Debug, Clone)]
-pub struct ExactEventMatchCondition {
+pub struct EventPropertyIsCondition {
    pub key: Cow<'static, str>,
    pub value: Cow<'static, SimpleJsonValue>,
 }

+/// The body of a [`Condition::EventPropertyIs`] that uses user_id or user_localpart as a pattern.
+#[derive(Serialize, Debug, Clone)]
+pub struct EventPropertyIsTypeCondition {
+    pub key: Cow<'static, str>,
+    // During serialization, the pattern_type property gets replaced with a
+    // pattern property of the correct value in synapse.push.clientformat.format_push_rules_for_user.
+    pub value_type: Cow<'static, EventMatchPatternType>,
+}
+
 /// The body of a [`Condition::RelatedEventMatch`]
 #[derive(Serialize, Deserialize, Debug, Clone)]
 pub struct RelatedEventMatchCondition {
@@ -698,55 +706,41 @@ fn test_deserialize_unstable_msc3931_condition() {
 }

 #[test]
-fn test_deserialize_unstable_msc3758_condition() {
+fn test_deserialize_event_property_is_condition() {
    // A string condition should work.
-    let json =
-        r#"{"kind":"com.beeper.msc3758.exact_event_match","key":"content.value","value":"foo"}"#;
+    let json = r#"{"kind":"event_property_is","key":"content.value","value":"foo"}"#;

    let condition: Condition = serde_json::from_str(json).unwrap();
    assert!(matches!(
        condition,
-        Condition::Known(KnownCondition::ExactEventMatch(_))
+        Condition::Known(KnownCondition::EventPropertyIs(_))
    ));

    // A boolean condition should work.
-    let json =
-        r#"{"kind":"com.beeper.msc3758.exact_event_match","key":"content.value","value":true}"#;
+    let json = r#"{"kind":"event_property_is","key":"content.value","value":true}"#;

    let condition: Condition = serde_json::from_str(json).unwrap();
    assert!(matches!(
        condition,
-        Condition::Known(KnownCondition::ExactEventMatch(_))
+        Condition::Known(KnownCondition::EventPropertyIs(_))
    ));

    // An integer condition should work.
-    let json = r#"{"kind":"com.beeper.msc3758.exact_event_match","key":"content.value","value":1}"#;
+    let json = r#"{"kind":"event_property_is","key":"content.value","value":1}"#;

    let condition: Condition = serde_json::from_str(json).unwrap();
    assert!(matches!(
        condition,
-        Condition::Known(KnownCondition::ExactEventMatch(_))
+        Condition::Known(KnownCondition::EventPropertyIs(_))
    ));

    // A null condition should work
-    let json =
-        r#"{"kind":"com.beeper.msc3758.exact_event_match","key":"content.value","value":null}"#;
+    let json = r#"{"kind":"event_property_is","key":"content.value","value":null}"#;

    let condition: Condition = serde_json::from_str(json).unwrap();
    assert!(matches!(
        condition,
-        Condition::Known(KnownCondition::ExactEventMatch(_))
-    ));
-}
-
-#[test]
-fn test_deserialize_unstable_msc3952_user_condition() {
-    let json = r#"{"kind":"org.matrix.msc3952.is_user_mention"}"#;
-
-    let condition: Condition = serde_json::from_str(json).unwrap();
-    assert!(matches!(
-        condition,
-        Condition::Known(KnownCondition::IsUserMention)
+        Condition::Known(KnownCondition::EventPropertyIs(_))
    ));
 }

--- a/scripts-dev/complement.sh
+++ b/scripts-dev/complement.sh
@@ -59,6 +59,11 @@ Run the complement test suite on Synapse.
        is important.
        Not suitable for use in CI in case the editable environment is impure.

+  --rebuild-editable
+        Force a rebuild of the editable build of Synapse.
+        This is occasionally useful if the built-in rebuild detection with
+        --editable fails, e.g. when changing configure_workers_and_start.py.
+
 For help on arguments to 'go test', run 'go help testflag'.
 EOF
 }
@@ -82,6 +87,9 @@ while [ $# -ge 1 ]; do
        "-e"|"--editable")
            use_editable_synapse=1
            ;;
+        "--rebuild-editable")
+            rebuild_editable_synapse=1
+            ;;
        *)
            # unknown arg: presumably an argument to gotest. break the loop.
            break
@@ -116,7 +124,9 @@ if [ -n "$use_editable_synapse" ]; then
    fi

    editable_mount="$(realpath .):/editable-src:z"
-    if docker inspect complement-synapse-editable &>/dev/null; then
+    if [ -n "$rebuild_editable_synapse" ]; then
+        unset skip_docker_build
+    elif docker inspect complement-synapse-editable &>/dev/null; then
        # complement-synapse-editable already exists: see if we can still use it:
        # - The Rust module must still be importable; it will fail to import if the Rust source has changed.
        # - The Poetry lock file must be the same (otherwise we assume dependencies have changed)
--- a/scripts-dev/lint.sh
+++ b/scripts-dev/lint.sh
@@ -112,7 +112,7 @@ python3 -m black "${files[@]}"

 # Catch any common programming mistakes in Python code.
 # --quiet suppresses the update check.
-ruff --quiet "${files[@]}"
+ruff --quiet --fix "${files[@]}"

 # Catch any common programming mistakes in Rust code.
 #
--- a/stubs/synapse/synapse_rust/push.pyi
+++ b/stubs/synapse/synapse_rust/push.pyi
@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.

-from typing import Any, Collection, Dict, Mapping, Optional, Sequence, Set, Tuple, Union
+from typing import Any, Collection, Dict, Mapping, Optional, Sequence, Tuple, Union

 from synapse.types import JsonDict, JsonValue

@@ -58,7 +58,6 @@ class PushRuleEvaluator:
        self,
        flattened_keys: Mapping[str, JsonValue],
        has_mentions: bool,
-        user_mentions: Set[str],
        room_member_count: int,
        sender_power_level: Optional[int],
        notification_power_levels: Mapping[str, int],
@@ -66,8 +65,6 @@ class PushRuleEvaluator:
        related_event_match_enabled: bool,
        room_version_feature_flags: Tuple[str, ...],
        msc3931_enabled: bool,
-        msc3758_exact_event_match: bool,
-        msc3966_exact_event_property_contains: bool,
    ): ...
    def run(
        self,
--- a/synapse/app/_base.py
+++ b/synapse/app/_base.py
@@ -58,9 +58,6 @@ from synapse.config._base import format_config_error
 from synapse.config.homeserver import HomeServerConfig
 from synapse.config.server import ListenerConfig, ManholeConfig
 from synapse.crypto import context_factory
-from synapse.events.presence_router import load_legacy_presence_router
-from synapse.events.spamcheck import load_legacy_spam_checkers
-from synapse.events.third_party_rules import load_legacy_third_party_event_rules
 from synapse.handlers.auth import load_legacy_password_auth_providers
 from synapse.http.site import SynapseSite
 from synapse.logging.context import PreserveLoggingContext
@@ -68,6 +65,15 @@ from synapse.logging.opentracing import init_tracer
 from synapse.metrics import install_gc_manager, register_threadpool
 from synapse.metrics.background_process_metrics import wrap_as_background_process
 from synapse.metrics.jemalloc import setup_jemalloc_stats
+from synapse.module_api.callbacks.presence_router_callbacks import (
+    load_legacy_presence_router,
+)
+from synapse.module_api.callbacks.spam_checker_callbacks import (
+    load_legacy_spam_checkers,
+)
+from synapse.module_api.callbacks.third_party_event_rules_callbacks import (
+    load_legacy_third_party_event_rules,
+)
 from synapse.types import ISynapseReactor
 from synapse.util import SYNAPSE_VERSION
 from synapse.util.caches.lrucache import setup_expire_lru_cache_entries
--- a/synapse/config/experimental.py
+++ b/synapse/config/experimental.py
@@ -166,23 +166,9 @@ class ExperimentalConfig(Config):
        # MSC3391: Removing account data.
        self.msc3391_enabled = experimental.get("msc3391_enabled", False)

-        # MSC3925: do not replace events with their edits
-        self.msc3925_inhibit_edit = experimental.get("msc3925_inhibit_edit", False)
-
-        # MSC3758: exact_event_match push rule condition
-        self.msc3758_exact_event_match = experimental.get(
-            "msc3758_exact_event_match", False
-        )
-
-        # MSC3873: Disambiguate event_match keys.
-        self.msc3873_escape_event_match_key = experimental.get(
-            "msc3873_escape_event_match_key", False
-        )
-
-        # MSC3952: Intentional mentions, this depends on MSC3758.
-        self.msc3952_intentional_mentions = (
-            experimental.get("msc3952_intentional_mentions", False)
-            and self.msc3758_exact_event_match
+        # MSC3952: Intentional mentions, this depends on MSC3966.
+        self.msc3952_intentional_mentions = experimental.get(
+            "msc3952_intentional_mentions", False
        )

        # MSC3959: Do not generate notifications for edits.
@@ -190,7 +176,5 @@ class ExperimentalConfig(Config):
            "msc3958_supress_edit_notifs", False
        )

-        # MSC3966: exact_event_property_contains push rule condition.
-        self.msc3966_exact_event_property_contains = experimental.get(
-            "msc3966_exact_event_property_contains", False
-        )
+        # MSC3967: Do not require UIA when first uploading cross signing keys
+        self.msc3967_enabled = experimental.get("msc3967_enabled", False)
--- a/synapse/event_auth.py
+++ b/synapse/event_auth.py
@@ -169,12 +169,15 @@ async def check_state_independent_auth_rules(

    # 2. Reject if event has auth_events that: ...
    if batched_auth_events:
-        auth_event_ids = event.auth_event_ids()
+        # Copy the batched auth events to avoid mutating them.
        auth_events = dict(batched_auth_events)
-        if set(auth_event_ids) - batched_auth_events.keys():
+        needed_auth_event_ids = set(event.auth_event_ids()) - batched_auth_events.keys()
+        if needed_auth_event_ids:
            auth_events.update(
                await store.get_events(
-                    set(auth_event_ids) - batched_auth_events.keys()
+                    needed_auth_event_ids,
+                    redact_behaviour=EventRedactBehaviour.as_is,
+                    allow_rejected=True,
                )
            )
    else:
--- a/synapse/events/presence_router.py
+++ b/synapse/events/presence_router.py
@@ -12,93 +12,19 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 import logging
-from typing import (
-    TYPE_CHECKING,
-    Any,
-    Awaitable,
-    Callable,
-    Dict,
-    Iterable,
-    List,
-    Optional,
-    Set,
-    TypeVar,
-    Union,
-)
-
-from typing_extensions import ParamSpec
+from typing import TYPE_CHECKING, Dict, Iterable, Set, Union

 from twisted.internet.defer import CancelledError

 from synapse.api.presence import UserPresenceState
-from synapse.util.async_helpers import delay_cancellation, maybe_awaitable
+from synapse.util.async_helpers import delay_cancellation

 if TYPE_CHECKING:
    from synapse.server import HomeServer

-GET_USERS_FOR_STATES_CALLBACK = Callable[
-    [Iterable[UserPresenceState]], Awaitable[Dict[str, Set[UserPresenceState]]]
-]
-# This must either return a set of strings or the constant PresenceRouter.ALL_USERS.
-GET_INTERESTED_USERS_CALLBACK = Callable[[str], Awaitable[Union[Set[str], str]]]
-
 logger = logging.getLogger(__name__)


-P = ParamSpec("P")
-R = TypeVar("R")
-
-
-def load_legacy_presence_router(hs: "HomeServer") -> None:
-    """Wrapper that loads a presence router module configured using the old
-    configuration, and registers the hooks they implement.
-    """
-
-    if hs.config.server.presence_router_module_class is None:
-        return
-
-    module = hs.config.server.presence_router_module_class
-    config = hs.config.server.presence_router_config
-    api = hs.get_module_api()
-
-    presence_router = module(config=config, module_api=api)
-
-    # The known hooks. If a module implements a method which name appears in this set,
-    # we'll want to register it.
-    presence_router_methods = {
-        "get_users_for_states",
-        "get_interested_users",
-    }
-
-    # All methods that the module provides should be async, but this wasn't enforced
-    # in the old module system, so we wrap them if needed
-    def async_wrapper(
-        f: Optional[Callable[P, R]]
-    ) -> Optional[Callable[P, Awaitable[R]]]:
-        # f might be None if the callback isn't implemented by the module. In this
-        # case we don't want to register a callback at all so we return None.
-        if f is None:
-            return None
-
-        def run(*args: P.args, **kwargs: P.kwargs) -> Awaitable[R]:
-            # Assertion required because mypy can't prove we won't change `f`
-            # back to `None`. See
-            # https://mypy.readthedocs.io/en/latest/common_issues.html#narrowing-and-inner-functions
-            assert f is not None
-
-            return maybe_awaitable(f(*args, **kwargs))
-
-        return run
-
-    # Register the hooks through the module API.
-    hooks: Dict[str, Optional[Callable[..., Any]]] = {
-        hook: async_wrapper(getattr(presence_router, hook, None))
-        for hook in presence_router_methods
-    }
-
-    api.register_presence_router_callbacks(**hooks)
-
-
 class PresenceRouter:
    """
    A module that the homeserver will call upon to help route user presence updates to
@@ -108,30 +34,7 @@ class PresenceRouter:
    ALL_USERS = "ALL"

    def __init__(self, hs: "HomeServer"):
-        # Initially there are no callbacks
-        self._get_users_for_states_callbacks: List[GET_USERS_FOR_STATES_CALLBACK] = []
-        self._get_interested_users_callbacks: List[GET_INTERESTED_USERS_CALLBACK] = []
-
-    def register_presence_router_callbacks(
-        self,
-        get_users_for_states: Optional[GET_USERS_FOR_STATES_CALLBACK] = None,
-        get_interested_users: Optional[GET_INTERESTED_USERS_CALLBACK] = None,
-    ) -> None:
-        # PresenceRouter modules are required to implement both of these methods
-        # or neither of them as they are assumed to act in a complementary manner
-        paired_methods = [get_users_for_states, get_interested_users]
-        if paired_methods.count(None) == 1:
-            raise RuntimeError(
-                "PresenceRouter modules must register neither or both of the paired callbacks: "
-                "[get_users_for_states, get_interested_users]"
-            )
-
-        # Append the methods provided to the lists of callbacks
-        if get_users_for_states is not None:
-            self._get_users_for_states_callbacks.append(get_users_for_states)
-
-        if get_interested_users is not None:
-            self._get_interested_users_callbacks.append(get_interested_users)
+        self._module_api_callbacks = hs.get_module_api_callbacks().presence_router

    async def get_users_for_states(
        self,
@@ -150,13 +53,13 @@ class PresenceRouter:
        """

        # Bail out early if we don't have any callbacks to run.
-        if len(self._get_users_for_states_callbacks) == 0:
+        if len(self._module_api_callbacks.get_users_for_states_callbacks) == 0:
            # Don't include any extra destinations for presence updates
            return {}

        users_for_states: Dict[str, Set[UserPresenceState]] = {}
        # run all the callbacks for get_users_for_states and combine the results
-        for callback in self._get_users_for_states_callbacks:
+        for callback in self._module_api_callbacks.get_users_for_states_callbacks:
            try:
                # Note: result is an object here, because we don't trust modules to
                # return the types they're supposed to.
@@ -206,13 +109,13 @@ class PresenceRouter:
        """

        # Bail out early if we don't have any callbacks to run.
-        if len(self._get_interested_users_callbacks) == 0:
+        if len(self._module_api_callbacks.get_interested_users_callbacks) == 0:
            # Don't report any additional interested users
            return set()

        interested_users = set()
        # run all the callbacks for get_interested_users and combine the results
-        for callback in self._get_interested_users_callbacks:
+        for callback in self._module_api_callbacks.get_interested_users_callbacks:
            try:
                result = await delay_cancellation(callback(user_id))
            except CancelledError:
--- a/synapse/events/snapshot.py
+++ b/synapse/events/snapshot.py
@@ -135,8 +135,6 @@ class EventContext(UnpersistedEventContextBase):
    delta_ids: Optional[StateMap[str]] = None
    app_service: Optional[ApplicationService] = None

-    _state_map_before_event: Optional[StateMap[str]] = None
-
    partial_state: bool = False

    @staticmethod
@@ -295,10 +293,6 @@ class EventContext(UnpersistedEventContextBase):
            Maps a (type, state_key) to the event ID of the state event matching
            this tuple.
        """
-        if self._state_map_before_event is not None:
-            if state_filter is not None:
-                return state_filter.filter_state(self._state_map_before_event)
-            return self._state_map_before_event

        assert self.state_group_before_event is not None
        return await self._storage.state.get_state_ids_for_group(
@@ -381,16 +375,26 @@ class UnpersistedEventContext(UnpersistedEventContextBase):

        events_and_persisted_context = []
        for event, unpersisted_context in amended_events_and_context:
-            context = EventContext(
-                storage=unpersisted_context._storage,
-                state_group=unpersisted_context.state_group_after_event,
-                state_group_before_event=unpersisted_context.state_group_before_event,
-                state_delta_due_to_event=unpersisted_context.state_delta_due_to_event,
-                partial_state=unpersisted_context.partial_state,
-                prev_group=unpersisted_context.prev_group_for_state_group_before_event,
-                delta_ids=unpersisted_context.delta_ids_to_state_group_before_event,
-                state_map_before_event=unpersisted_context.state_map_before_event,
-            )
+            if event.is_state():
+                context = EventContext(
+                    storage=unpersisted_context._storage,
+                    state_group=unpersisted_context.state_group_after_event,
+                    state_group_before_event=unpersisted_context.state_group_before_event,
+                    state_delta_due_to_event=unpersisted_context.state_delta_due_to_event,
+                    partial_state=unpersisted_context.partial_state,
+                    prev_group=unpersisted_context.state_group_before_event,
+                    delta_ids=unpersisted_context.state_delta_due_to_event,
+                )
+            else:
+                context = EventContext(
+                    storage=unpersisted_context._storage,
+                    state_group=unpersisted_context.state_group_after_event,
+                    state_group_before_event=unpersisted_context.state_group_before_event,
+                    state_delta_due_to_event=unpersisted_context.state_delta_due_to_event,
+                    partial_state=unpersisted_context.partial_state,
+                    prev_group=unpersisted_context.prev_group_for_state_group_before_event,
+                    delta_ids=unpersisted_context.delta_ids_to_state_group_before_event,
+                )
            events_and_persisted_context.append((event, context))
        return events_and_persisted_context

--- a/synapse/events/spamcheck.py
+++ b/synapse/events/spamcheck.py
@@ -13,19 +13,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.

-import inspect
 import logging
-from typing import (
-    TYPE_CHECKING,
-    Any,
-    Awaitable,
-    Callable,
-    Collection,
-    List,
-    Optional,
-    Tuple,
-    Union,
-)
+from typing import TYPE_CHECKING, Collection, Optional, Tuple, Union

 # `Literal` appears with Python 3.8.
 from typing_extensions import Literal
@@ -37,7 +26,7 @@ from synapse.media._base import FileInfo
 from synapse.media.media_storage import ReadableFileWrapper
 from synapse.spam_checker_api import RegistrationBehaviour
 from synapse.types import JsonDict, RoomAlias, UserProfile
-from synapse.util.async_helpers import delay_cancellation, maybe_awaitable
+from synapse.util.async_helpers import delay_cancellation
 from synapse.util.metrics import Measure

 if TYPE_CHECKING:
@@ -46,338 +35,13 @@ if TYPE_CHECKING:

 logger = logging.getLogger(__name__)

-CHECK_EVENT_FOR_SPAM_CALLBACK = Callable[
-    ["synapse.events.EventBase"],
-    Awaitable[
-        Union[
-            str,
-            Codes,
-            # Highly experimental, not officially part of the spamchecker API, may
-            # disappear without warning depending on the results of ongoing
-            # experiments.
-            # Use this to return additional information as part of an error.
-            Tuple[Codes, JsonDict],
-            # Deprecated
-            bool,
-        ]
-    ],
-]
-SHOULD_DROP_FEDERATED_EVENT_CALLBACK = Callable[
-    ["synapse.events.EventBase"],
-    Awaitable[Union[bool, str]],
-]
-USER_MAY_JOIN_ROOM_CALLBACK = Callable[
-    [str, str, bool],
-    Awaitable[
-        Union[
-            Literal["NOT_SPAM"],
-            Codes,
-            # Highly experimental, not officially part of the spamchecker API, may
-            # disappear without warning depending on the results of ongoing
-            # experiments.
-            # Use this to return additional information as part of an error.
-            Tuple[Codes, JsonDict],
-            # Deprecated
-            bool,
-        ]
-    ],
-]
-USER_MAY_INVITE_CALLBACK = Callable[
-    [str, str, str],
-    Awaitable[
-        Union[
-            Literal["NOT_SPAM"],
-            Codes,
-            # Highly experimental, not officially part of the spamchecker API, may
-            # disappear without warning depending on the results of ongoing
-            # experiments.
-            # Use this to return additional information as part of an error.
-            Tuple[Codes, JsonDict],
-            # Deprecated
-            bool,
-        ]
-    ],
-]
-USER_MAY_SEND_3PID_INVITE_CALLBACK = Callable[
-    [str, str, str, str],
-    Awaitable[
-        Union[
-            Literal["NOT_SPAM"],
-            Codes,
-            # Highly experimental, not officially part of the spamchecker API, may
-            # disappear without warning depending on the results of ongoing
-            # experiments.
-            # Use this to return additional information as part of an error.
-            Tuple[Codes, JsonDict],
-            # Deprecated
-            bool,
-        ]
-    ],
-]
-USER_MAY_CREATE_ROOM_CALLBACK = Callable[
-    [str],
-    Awaitable[
-        Union[
-            Literal["NOT_SPAM"],
-            Codes,
-            # Highly experimental, not officially part of the spamchecker API, may
-            # disappear without warning depending on the results of ongoing
-            # experiments.
-            # Use this to return additional information as part of an error.
-            Tuple[Codes, JsonDict],
-            # Deprecated
-            bool,
-        ]
-    ],
-]
-USER_MAY_CREATE_ROOM_ALIAS_CALLBACK = Callable[
-    [str, RoomAlias],
-    Awaitable[
-        Union[
-            Literal["NOT_SPAM"],
-            Codes,
-            # Highly experimental, not officially part of the spamchecker API, may
-            # disappear without warning depending on the results of ongoing
-            # experiments.
-            # Use this to return additional information as part of an error.
-            Tuple[Codes, JsonDict],
-            # Deprecated
-            bool,
-        ]
-    ],
-]
-USER_MAY_PUBLISH_ROOM_CALLBACK = Callable[
-    [str, str],
-    Awaitable[
-        Union[
-            Literal["NOT_SPAM"],
-            Codes,
-            # Highly experimental, not officially part of the spamchecker API, may
-            # disappear without warning depending on the results of ongoing
-            # experiments.
-            # Use this to return additional information as part of an error.
-            Tuple[Codes, JsonDict],
-            # Deprecated
-            bool,
-        ]
-    ],
-]
-CHECK_USERNAME_FOR_SPAM_CALLBACK = Callable[[UserProfile], Awaitable[bool]]
-LEGACY_CHECK_REGISTRATION_FOR_SPAM_CALLBACK = Callable[
-    [
-        Optional[dict],
-        Optional[str],
-        Collection[Tuple[str, str]],
-    ],
-    Awaitable[RegistrationBehaviour],
-]
-CHECK_REGISTRATION_FOR_SPAM_CALLBACK = Callable[
-    [
-        Optional[dict],
-        Optional[str],
-        Collection[Tuple[str, str]],
-        Optional[str],
-    ],
-    Awaitable[RegistrationBehaviour],
-]
-CHECK_MEDIA_FILE_FOR_SPAM_CALLBACK = Callable[
-    [ReadableFileWrapper, FileInfo],
-    Awaitable[
-        Union[
-            Literal["NOT_SPAM"],
-            Codes,
-            # Highly experimental, not officially part of the spamchecker API, may
-            # disappear without warning depending on the results of ongoing
-            # experiments.
-            # Use this to return additional information as part of an error.
-            Tuple[Codes, JsonDict],
-            # Deprecated
-            bool,
-        ]
-    ],
-]
-
-
-def load_legacy_spam_checkers(hs: "synapse.server.HomeServer") -> None:
-    """Wrapper that loads spam checkers configured using the old configuration, and
-    registers the spam checker hooks they implement.
-    """
-    spam_checkers: List[Any] = []
-    api = hs.get_module_api()
-    for module, config in hs.config.spamchecker.spam_checkers:
-        # Older spam checkers don't accept the `api` argument, so we
-        # try and detect support.
-        spam_args = inspect.getfullargspec(module)
-        if "api" in spam_args.args:
-            spam_checkers.append(module(config=config, api=api))
-        else:
-            spam_checkers.append(module(config=config))
-
-    # The known spam checker hooks. If a spam checker module implements a method
-    # which name appears in this set, we'll want to register it.
-    spam_checker_methods = {
-        "check_event_for_spam",
-        "user_may_invite",
-        "user_may_create_room",
-        "user_may_create_room_alias",
-        "user_may_publish_room",
-        "check_username_for_spam",
-        "check_registration_for_spam",
-        "check_media_file_for_spam",
-    }
-
-    for spam_checker in spam_checkers:
-        # Methods on legacy spam checkers might not be async, so we wrap them around a
-        # wrapper that will call maybe_awaitable on the result.
-        def async_wrapper(f: Optional[Callable]) -> Optional[Callable[..., Awaitable]]:
-            # f might be None if the callback isn't implemented by the module. In this
-            # case we don't want to register a callback at all so we return None.
-            if f is None:
-                return None
-
-            wrapped_func = f
-
-            if f.__name__ == "check_registration_for_spam":
-                checker_args = inspect.signature(f)
-                if len(checker_args.parameters) == 3:
-                    # Backwards compatibility; some modules might implement a hook that
-                    # doesn't expect a 4th argument. In this case, wrap it in a function
-                    # that gives it only 3 arguments and drops the auth_provider_id on
-                    # the floor.
-                    def wrapper(
-                        email_threepid: Optional[dict],
-                        username: Optional[str],
-                        request_info: Collection[Tuple[str, str]],
-                        auth_provider_id: Optional[str],
-                    ) -> Union[Awaitable[RegistrationBehaviour], RegistrationBehaviour]:
-                        # Assertion required because mypy can't prove we won't
-                        # change `f` back to `None`. See
-                        # https://mypy.readthedocs.io/en/latest/common_issues.html#narrowing-and-inner-functions
-                        assert f is not None
-
-                        return f(
-                            email_threepid,
-                            username,
-                            request_info,
-                        )
-
-                    wrapped_func = wrapper
-                elif len(checker_args.parameters) != 4:
-                    raise RuntimeError(
-                        "Bad signature for callback check_registration_for_spam",
-                    )
-
-            def run(*args: Any, **kwargs: Any) -> Awaitable:
-                # Assertion required because mypy can't prove we won't change `f`
-                # back to `None`. See
-                # https://mypy.readthedocs.io/en/latest/common_issues.html#narrowing-and-inner-functions
-                assert wrapped_func is not None
-
-                return maybe_awaitable(wrapped_func(*args, **kwargs))
-
-            return run
-
-        # Register the hooks through the module API.
-        hooks = {
-            hook: async_wrapper(getattr(spam_checker, hook, None))
-            for hook in spam_checker_methods
-        }
-
-        api.register_spam_checker_callbacks(**hooks)
-

 class SpamChecker:
    NOT_SPAM: Literal["NOT_SPAM"] = "NOT_SPAM"

-    def __init__(self, hs: "synapse.server.HomeServer") -> None:
-        self.hs = hs
+    def __init__(self, hs: "synapse.server.HomeServer"):
        self.clock = hs.get_clock()
-
-        self._check_event_for_spam_callbacks: List[CHECK_EVENT_FOR_SPAM_CALLBACK] = []
-        self._should_drop_federated_event_callbacks: List[
-            SHOULD_DROP_FEDERATED_EVENT_CALLBACK
-        ] = []
-        self._user_may_join_room_callbacks: List[USER_MAY_JOIN_ROOM_CALLBACK] = []
-        self._user_may_invite_callbacks: List[USER_MAY_INVITE_CALLBACK] = []
-        self._user_may_send_3pid_invite_callbacks: List[
-            USER_MAY_SEND_3PID_INVITE_CALLBACK
-        ] = []
-        self._user_may_create_room_callbacks: List[USER_MAY_CREATE_ROOM_CALLBACK] = []
-        self._user_may_create_room_alias_callbacks: List[
-            USER_MAY_CREATE_ROOM_ALIAS_CALLBACK
-        ] = []
-        self._user_may_publish_room_callbacks: List[USER_MAY_PUBLISH_ROOM_CALLBACK] = []
-        self._check_username_for_spam_callbacks: List[
-            CHECK_USERNAME_FOR_SPAM_CALLBACK
-        ] = []
-        self._check_registration_for_spam_callbacks: List[
-            CHECK_REGISTRATION_FOR_SPAM_CALLBACK
-        ] = []
-        self._check_media_file_for_spam_callbacks: List[
-            CHECK_MEDIA_FILE_FOR_SPAM_CALLBACK
-        ] = []
-
-    def register_callbacks(
-        self,
-        check_event_for_spam: Optional[CHECK_EVENT_FOR_SPAM_CALLBACK] = None,
-        should_drop_federated_event: Optional[
-            SHOULD_DROP_FEDERATED_EVENT_CALLBACK
-        ] = None,
-        user_may_join_room: Optional[USER_MAY_JOIN_ROOM_CALLBACK] = None,
-        user_may_invite: Optional[USER_MAY_INVITE_CALLBACK] = None,
-        user_may_send_3pid_invite: Optional[USER_MAY_SEND_3PID_INVITE_CALLBACK] = None,
-        user_may_create_room: Optional[USER_MAY_CREATE_ROOM_CALLBACK] = None,
-        user_may_create_room_alias: Optional[
-            USER_MAY_CREATE_ROOM_ALIAS_CALLBACK
-        ] = None,
-        user_may_publish_room: Optional[USER_MAY_PUBLISH_ROOM_CALLBACK] = None,
-        check_username_for_spam: Optional[CHECK_USERNAME_FOR_SPAM_CALLBACK] = None,
-        check_registration_for_spam: Optional[
-            CHECK_REGISTRATION_FOR_SPAM_CALLBACK
-        ] = None,
-        check_media_file_for_spam: Optional[CHECK_MEDIA_FILE_FOR_SPAM_CALLBACK] = None,
-    ) -> None:
-        """Register callbacks from module for each hook."""
-        if check_event_for_spam is not None:
-            self._check_event_for_spam_callbacks.append(check_event_for_spam)
-
-        if should_drop_federated_event is not None:
-            self._should_drop_federated_event_callbacks.append(
-                should_drop_federated_event
-            )
-
-        if user_may_join_room is not None:
-            self._user_may_join_room_callbacks.append(user_may_join_room)
-
-        if user_may_invite is not None:
-            self._user_may_invite_callbacks.append(user_may_invite)
-
-        if user_may_send_3pid_invite is not None:
-            self._user_may_send_3pid_invite_callbacks.append(
-                user_may_send_3pid_invite,
-            )
-
-        if user_may_create_room is not None:
-            self._user_may_create_room_callbacks.append(user_may_create_room)
-
-        if user_may_create_room_alias is not None:
-            self._user_may_create_room_alias_callbacks.append(
-                user_may_create_room_alias,
-            )
-
-        if user_may_publish_room is not None:
-            self._user_may_publish_room_callbacks.append(user_may_publish_room)
-
-        if check_username_for_spam is not None:
-            self._check_username_for_spam_callbacks.append(check_username_for_spam)
-
-        if check_registration_for_spam is not None:
-            self._check_registration_for_spam_callbacks.append(
-                check_registration_for_spam,
-            )
-
-        if check_media_file_for_spam is not None:
-            self._check_media_file_for_spam_callbacks.append(check_media_file_for_spam)
+        self._module_api_callbacks = hs.get_module_api_callbacks().spam_checker

    @trace
    async def check_event_for_spam(
@@ -401,7 +65,7 @@ class SpamChecker:
                string should be used as the client-facing error message. This usage is
                generally discouraged as it doesn't support internationalization.
        """
-        for callback in self._check_event_for_spam_callbacks:
+        for callback in self._module_api_callbacks.check_event_for_spam_callbacks:
            with Measure(
                self.clock, "{}.{}".format(callback.__module__, callback.__qualname__)
            ):
@@ -456,7 +120,9 @@ class SpamChecker:
        Returns:
            True if the event should be silently dropped
        """
-        for callback in self._should_drop_federated_event_callbacks:
+        for (
+            callback
+        ) in self._module_api_callbacks.should_drop_federated_event_callbacks:
            with Measure(
                self.clock, "{}.{}".format(callback.__module__, callback.__qualname__)
            ):
@@ -480,7 +146,7 @@ class SpamChecker:
        Returns:
            NOT_SPAM if the operation is permitted, [Codes, Dict] otherwise.
        """
-        for callback in self._user_may_join_room_callbacks:
+        for callback in self._module_api_callbacks.user_may_join_room_callbacks:
            with Measure(
                self.clock, "{}.{}".format(callback.__module__, callback.__qualname__)
            ):
@@ -521,7 +187,7 @@ class SpamChecker:
        Returns:
            NOT_SPAM if the operation is permitted, Codes otherwise.
        """
-        for callback in self._user_may_invite_callbacks:
+        for callback in self._module_api_callbacks.user_may_invite_callbacks:
            with Measure(
                self.clock, "{}.{}".format(callback.__module__, callback.__qualname__)
            ):
@@ -568,7 +234,7 @@ class SpamChecker:
        Returns:
            NOT_SPAM if the operation is permitted, Codes otherwise.
        """
-        for callback in self._user_may_send_3pid_invite_callbacks:
+        for callback in self._module_api_callbacks.user_may_send_3pid_invite_callbacks:
            with Measure(
                self.clock, "{}.{}".format(callback.__module__, callback.__qualname__)
            ):
@@ -605,7 +271,7 @@ class SpamChecker:
        Args:
            userid: The ID of the user attempting to create a room
        """
-        for callback in self._user_may_create_room_callbacks:
+        for callback in self._module_api_callbacks.user_may_create_room_callbacks:
            with Measure(
                self.clock, "{}.{}".format(callback.__module__, callback.__qualname__)
            ):
@@ -641,7 +307,7 @@ class SpamChecker:
            room_alias: The alias to be created

        """
-        for callback in self._user_may_create_room_alias_callbacks:
+        for callback in self._module_api_callbacks.user_may_create_room_alias_callbacks:
            with Measure(
                self.clock, "{}.{}".format(callback.__module__, callback.__qualname__)
            ):
@@ -676,7 +342,7 @@ class SpamChecker:
            userid: The user ID attempting to publish the room
            room_id: The ID of the room that would be published
        """
-        for callback in self._user_may_publish_room_callbacks:
+        for callback in self._module_api_callbacks.user_may_publish_room_callbacks:
            with Measure(
                self.clock, "{}.{}".format(callback.__module__, callback.__qualname__)
            ):
@@ -717,7 +383,7 @@ class SpamChecker:
        Returns:
            True if the user is spammy.
        """
-        for callback in self._check_username_for_spam_callbacks:
+        for callback in self._module_api_callbacks.check_username_for_spam_callbacks:
            with Measure(
                self.clock, "{}.{}".format(callback.__module__, callback.__qualname__)
            ):
@@ -751,7 +417,9 @@ class SpamChecker:
            Enum for how the request should be handled
        """

-        for callback in self._check_registration_for_spam_callbacks:
+        for (
+            callback
+        ) in self._module_api_callbacks.check_registration_for_spam_callbacks:
            with Measure(
                self.clock, "{}.{}".format(callback.__module__, callback.__qualname__)
            ):
@@ -794,7 +462,7 @@ class SpamChecker:
            file_info: Metadata about the file.
        """

-        for callback in self._check_media_file_for_spam_callbacks:
+        for callback in self._module_api_callbacks.check_media_file_for_spam_callbacks:
            with Measure(
                self.clock, "{}.{}".format(callback.__module__, callback.__qualname__)
            ):
--- a/synapse/events/third_party_rules.py
+++ b/synapse/events/third_party_rules.py
@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 import logging
-from typing import TYPE_CHECKING, Any, Awaitable, Callable, List, Optional, Tuple
+from typing import TYPE_CHECKING, Optional, Tuple

 from twisted.internet.defer import CancelledError

@@ -21,7 +21,7 @@ from synapse.events import EventBase
 from synapse.events.snapshot import UnpersistedEventContextBase
 from synapse.storage.roommember import ProfileInfo
 from synapse.types import Requester, StateMap
-from synapse.util.async_helpers import delay_cancellation, maybe_awaitable
+from synapse.util.async_helpers import delay_cancellation

 if TYPE_CHECKING:
    from synapse.server import HomeServer
@@ -29,117 +29,6 @@ if TYPE_CHECKING:
 logger = logging.getLogger(__name__)


-CHECK_EVENT_ALLOWED_CALLBACK = Callable[
-    [EventBase, StateMap[EventBase]], Awaitable[Tuple[bool, Optional[dict]]]
-]
-ON_CREATE_ROOM_CALLBACK = Callable[[Requester, dict, bool], Awaitable]
-CHECK_THREEPID_CAN_BE_INVITED_CALLBACK = Callable[
-    [str, str, StateMap[EventBase]], Awaitable[bool]
-]
-CHECK_VISIBILITY_CAN_BE_MODIFIED_CALLBACK = Callable[
-    [str, StateMap[EventBase], str], Awaitable[bool]
-]
-ON_NEW_EVENT_CALLBACK = Callable[[EventBase, StateMap[EventBase]], Awaitable]
-CHECK_CAN_SHUTDOWN_ROOM_CALLBACK = Callable[[str, str], Awaitable[bool]]
-CHECK_CAN_DEACTIVATE_USER_CALLBACK = Callable[[str, bool], Awaitable[bool]]
-ON_PROFILE_UPDATE_CALLBACK = Callable[[str, ProfileInfo, bool, bool], Awaitable]
-ON_USER_DEACTIVATION_STATUS_CHANGED_CALLBACK = Callable[[str, bool, bool], Awaitable]
-ON_THREEPID_BIND_CALLBACK = Callable[[str, str, str], Awaitable]
-ON_ADD_USER_THIRD_PARTY_IDENTIFIER_CALLBACK = Callable[[str, str, str], Awaitable]
-ON_REMOVE_USER_THIRD_PARTY_IDENTIFIER_CALLBACK = Callable[[str, str, str], Awaitable]
-
-
-def load_legacy_third_party_event_rules(hs: "HomeServer") -> None:
-    """Wrapper that loads a third party event rules module configured using the old
-    configuration, and registers the hooks they implement.
-    """
-    if hs.config.thirdpartyrules.third_party_event_rules is None:
-        return
-
-    module, config = hs.config.thirdpartyrules.third_party_event_rules
-
-    api = hs.get_module_api()
-    third_party_rules = module(config=config, module_api=api)
-
-    # The known hooks. If a module implements a method which name appears in this set,
-    # we'll want to register it.
-    third_party_event_rules_methods = {
-        "check_event_allowed",
-        "on_create_room",
-        "check_threepid_can_be_invited",
-        "check_visibility_can_be_modified",
-    }
-
-    def async_wrapper(f: Optional[Callable]) -> Optional[Callable[..., Awaitable]]:
-        # f might be None if the callback isn't implemented by the module. In this
-        # case we don't want to register a callback at all so we return None.
-        if f is None:
-            return None
-
-        # We return a separate wrapper for these methods because, in order to wrap them
-        # correctly, we need to await its result. Therefore it doesn't make a lot of
-        # sense to make it go through the run() wrapper.
-        if f.__name__ == "check_event_allowed":
-            # We need to wrap check_event_allowed because its old form would return either
-            # a boolean or a dict, but now we want to return the dict separately from the
-            # boolean.
-            async def wrap_check_event_allowed(
-                event: EventBase,
-                state_events: StateMap[EventBase],
-            ) -> Tuple[bool, Optional[dict]]:
-                # Assertion required because mypy can't prove we won't change
-                # `f` back to `None`. See
-                # https://mypy.readthedocs.io/en/latest/common_issues.html#narrowing-and-inner-functions
-                assert f is not None
-
-                res = await f(event, state_events)
-                if isinstance(res, dict):
-                    return True, res
-                else:
-                    return res, None
-
-            return wrap_check_event_allowed
-
-        if f.__name__ == "on_create_room":
-            # We need to wrap on_create_room because its old form would return a boolean
-            # if the room creation is denied, but now we just want it to raise an
-            # exception.
-            async def wrap_on_create_room(
-                requester: Requester, config: dict, is_requester_admin: bool
-            ) -> None:
-                # Assertion required because mypy can't prove we won't change
-                # `f` back to `None`. See
-                # https://mypy.readthedocs.io/en/latest/common_issues.html#narrowing-and-inner-functions
-                assert f is not None
-
-                res = await f(requester, config, is_requester_admin)
-                if res is False:
-                    raise SynapseError(
-                        403,
-                        "Room creation forbidden with these parameters",
-                    )
-
-            return wrap_on_create_room
-
-        def run(*args: Any, **kwargs: Any) -> Awaitable:
-            # Assertion required because mypy can't prove we won't change  `f`
-            # back to `None`. See
-            # https://mypy.readthedocs.io/en/latest/common_issues.html#narrowing-and-inner-functions
-            assert f is not None
-
-            return maybe_awaitable(f(*args, **kwargs))
-
-        return run
-
-    # Register the hooks through the module API.
-    hooks = {
-        hook: async_wrapper(getattr(third_party_rules, hook, None))
-        for hook in third_party_event_rules_methods
-    }
-
-    api.register_third_party_rules_callbacks(**hooks)
-
-
 class ThirdPartyEventRules:
    """Allows server admins to provide a Python module implementing an extra
    set of rules to apply when processing events.
@@ -153,99 +42,9 @@ class ThirdPartyEventRules:

        self.store = hs.get_datastores().main
        self._storage_controllers = hs.get_storage_controllers()
-
-        self._check_event_allowed_callbacks: List[CHECK_EVENT_ALLOWED_CALLBACK] = []
-        self._on_create_room_callbacks: List[ON_CREATE_ROOM_CALLBACK] = []
-        self._check_threepid_can_be_invited_callbacks: List[
-            CHECK_THREEPID_CAN_BE_INVITED_CALLBACK
-        ] = []
-        self._check_visibility_can_be_modified_callbacks: List[
-            CHECK_VISIBILITY_CAN_BE_MODIFIED_CALLBACK
-        ] = []
-        self._on_new_event_callbacks: List[ON_NEW_EVENT_CALLBACK] = []
-        self._check_can_shutdown_room_callbacks: List[
-            CHECK_CAN_SHUTDOWN_ROOM_CALLBACK
-        ] = []
-        self._check_can_deactivate_user_callbacks: List[
-            CHECK_CAN_DEACTIVATE_USER_CALLBACK
-        ] = []
-        self._on_profile_update_callbacks: List[ON_PROFILE_UPDATE_CALLBACK] = []
-        self._on_user_deactivation_status_changed_callbacks: List[
-            ON_USER_DEACTIVATION_STATUS_CHANGED_CALLBACK
-        ] = []
-        self._on_threepid_bind_callbacks: List[ON_THREEPID_BIND_CALLBACK] = []
-        self._on_add_user_third_party_identifier_callbacks: List[
-            ON_ADD_USER_THIRD_PARTY_IDENTIFIER_CALLBACK
-        ] = []
-        self._on_remove_user_third_party_identifier_callbacks: List[
-            ON_REMOVE_USER_THIRD_PARTY_IDENTIFIER_CALLBACK
-        ] = []
-
-    def register_third_party_rules_callbacks(
-        self,
-        check_event_allowed: Optional[CHECK_EVENT_ALLOWED_CALLBACK] = None,
-        on_create_room: Optional[ON_CREATE_ROOM_CALLBACK] = None,
-        check_threepid_can_be_invited: Optional[
-            CHECK_THREEPID_CAN_BE_INVITED_CALLBACK
-        ] = None,
-        check_visibility_can_be_modified: Optional[
-            CHECK_VISIBILITY_CAN_BE_MODIFIED_CALLBACK
-        ] = None,
-        on_new_event: Optional[ON_NEW_EVENT_CALLBACK] = None,
-        check_can_shutdown_room: Optional[CHECK_CAN_SHUTDOWN_ROOM_CALLBACK] = None,
-        check_can_deactivate_user: Optional[CHECK_CAN_DEACTIVATE_USER_CALLBACK] = None,
-        on_profile_update: Optional[ON_PROFILE_UPDATE_CALLBACK] = None,
-        on_user_deactivation_status_changed: Optional[
-            ON_USER_DEACTIVATION_STATUS_CHANGED_CALLBACK
-        ] = None,
-        on_threepid_bind: Optional[ON_THREEPID_BIND_CALLBACK] = None,
-        on_add_user_third_party_identifier: Optional[
-            ON_ADD_USER_THIRD_PARTY_IDENTIFIER_CALLBACK
-        ] = None,
-        on_remove_user_third_party_identifier: Optional[
-            ON_REMOVE_USER_THIRD_PARTY_IDENTIFIER_CALLBACK
-        ] = None,
-    ) -> None:
-        """Register callbacks from modules for each hook."""
-        if check_event_allowed is not None:
-            self._check_event_allowed_callbacks.append(check_event_allowed)
-
-        if on_create_room is not None:
-            self._on_create_room_callbacks.append(on_create_room)
-
-        if check_threepid_can_be_invited is not None:
-            self._check_threepid_can_be_invited_callbacks.append(
-                check_threepid_can_be_invited,
-            )
-
-        if check_visibility_can_be_modified is not None:
-            self._check_visibility_can_be_modified_callbacks.append(
-                check_visibility_can_be_modified,
-            )
-
-        if on_new_event is not None:
-            self._on_new_event_callbacks.append(on_new_event)
-
-        if check_can_shutdown_room is not None:
-            self._check_can_shutdown_room_callbacks.append(check_can_shutdown_room)
-
-        if check_can_deactivate_user is not None:
-            self._check_can_deactivate_user_callbacks.append(check_can_deactivate_user)
-        if on_profile_update is not None:
-            self._on_profile_update_callbacks.append(on_profile_update)
-
-        if on_user_deactivation_status_changed is not None:
-            self._on_user_deactivation_status_changed_callbacks.append(
-                on_user_deactivation_status_changed,
-            )
-
-        if on_threepid_bind is not None:
-            self._on_threepid_bind_callbacks.append(on_threepid_bind)
-
-        if on_add_user_third_party_identifier is not None:
-            self._on_add_user_third_party_identifier_callbacks.append(
-                on_add_user_third_party_identifier
-            )
+        self._module_api_callbacks = (
+            hs.get_module_api_callbacks().third_party_event_rules
+        )

    async def check_event_allowed(
        self,
@@ -269,7 +68,7 @@ class ThirdPartyEventRules:
            The result from the ThirdPartyRules module, as above.
        """
        # Bail out early without hitting the store if we don't have any callbacks to run.
-        if len(self._check_event_allowed_callbacks) == 0:
+        if len(self._module_api_callbacks.check_event_allowed_callbacks) == 0:
            return True, None

        prev_state_ids = await context.get_prev_state_ids()
@@ -283,7 +82,7 @@ class ThirdPartyEventRules:
        # the hashes and signatures.
        event.freeze()

-        for callback in self._check_event_allowed_callbacks:
+        for callback in self._module_api_callbacks.check_event_allowed_callbacks:
            try:
                res, replacement_data = await delay_cancellation(
                    callback(event, state_events)
@@ -324,7 +123,7 @@ class ThirdPartyEventRules:
            config: The creation config from the client.
            is_requester_admin: If the requester is an admin
        """
-        for callback in self._on_create_room_callbacks:
+        for callback in self._module_api_callbacks.on_create_room_callbacks:
            try:
                await callback(requester, config, is_requester_admin)
            except Exception as e:
@@ -352,12 +151,14 @@ class ThirdPartyEventRules:
            True if the 3PID can be invited, False if not.
        """
        # Bail out early without hitting the store if we don't have any callbacks to run.
-        if len(self._check_threepid_can_be_invited_callbacks) == 0:
+        if len(self._module_api_callbacks.check_threepid_can_be_invited_callbacks) == 0:
            return True

        state_events = await self._get_state_map_for_room(room_id)

-        for callback in self._check_threepid_can_be_invited_callbacks:
+        for (
+            callback
+        ) in self._module_api_callbacks.check_threepid_can_be_invited_callbacks:
            try:
                threepid_can_be_invited = await delay_cancellation(
                    callback(medium, address, state_events)
@@ -385,12 +186,17 @@ class ThirdPartyEventRules:
            True if the room's visibility can be modified, False if not.
        """
        # Bail out early without hitting the store if we don't have any callback
-        if len(self._check_visibility_can_be_modified_callbacks) == 0:
+        if (
+            len(self._module_api_callbacks.check_visibility_can_be_modified_callbacks)
+            == 0
+        ):
            return True

        state_events = await self._get_state_map_for_room(room_id)

-        for callback in self._check_visibility_can_be_modified_callbacks:
+        for (
+            callback
+        ) in self._module_api_callbacks.check_visibility_can_be_modified_callbacks:
            try:
                visibility_can_be_modified = await delay_cancellation(
                    callback(room_id, state_events, new_visibility)
@@ -412,13 +218,13 @@ class ThirdPartyEventRules:
            event_id: The ID of the event.
        """
        # Bail out early without hitting the store if we don't have any callbacks
-        if len(self._on_new_event_callbacks) == 0:
+        if len(self._module_api_callbacks.on_new_event_callbacks) == 0:
            return

        event = await self.store.get_event(event_id)
        state_events = await self._get_state_map_for_room(event.room_id)

-        for callback in self._on_new_event_callbacks:
+        for callback in self._module_api_callbacks.on_new_event_callbacks:
            try:
                await callback(event, state_events)
            except Exception as e:
@@ -434,7 +240,7 @@ class ThirdPartyEventRules:
            requester: The ID of the user requesting the shutdown.
            room_id: The ID of the room.
        """
-        for callback in self._check_can_shutdown_room_callbacks:
+        for callback in self._module_api_callbacks.check_can_shutdown_room_callbacks:
            try:
                can_shutdown_room = await delay_cancellation(callback(user_id, room_id))
                if can_shutdown_room is False:
@@ -459,7 +265,7 @@ class ThirdPartyEventRules:
            requester
            user_id: The ID of the room.
        """
-        for callback in self._check_can_deactivate_user_callbacks:
+        for callback in self._module_api_callbacks.check_can_deactivate_user_callbacks:
            try:
                can_deactivate_user = await delay_cancellation(
                    callback(user_id, by_admin)
@@ -497,7 +303,7 @@ class ThirdPartyEventRules:
            by_admin: Whether the profile update was performed by a server admin.
            deactivation: Whether this change was made while deactivating the user.
        """
-        for callback in self._on_profile_update_callbacks:
+        for callback in self._module_api_callbacks.on_profile_update_callbacks:
            try:
                await callback(user_id, new_profile, by_admin, deactivation)
            except Exception as e:
@@ -515,7 +321,9 @@ class ThirdPartyEventRules:
            deactivated: Whether the user is now deactivated.
            by_admin: Whether the deactivation was performed by a server admin.
        """
-        for callback in self._on_user_deactivation_status_changed_callbacks:
+        for (
+            callback
+        ) in self._module_api_callbacks.on_user_deactivation_status_changed_callbacks:
            try:
                await callback(user_id, deactivated, by_admin)
            except Exception as e:
@@ -538,7 +346,7 @@ class ThirdPartyEventRules:
            medium: the threepid's medium.
            address: the threepid's address.
        """
-        for callback in self._on_threepid_bind_callbacks:
+        for callback in self._module_api_callbacks.on_threepid_bind_callbacks:
            try:
                await callback(user_id, medium, address)
            except Exception as e:
@@ -557,7 +365,9 @@ class ThirdPartyEventRules:
            medium: The medium of the third-party ID (email, msisdn).
            address: The address of the third-party ID (i.e. an email address).
        """
-        for callback in self._on_add_user_third_party_identifier_callbacks:
+        for (
+            callback
+        ) in self._module_api_callbacks.on_add_user_third_party_identifier_callbacks:
            try:
                await callback(user_id, medium, address)
            except Exception as e:
@@ -579,7 +389,9 @@ class ThirdPartyEventRules:
            medium: The medium of the third-party ID (email, msisdn).
            address: The address of the third-party ID (i.e. an email address).
        """
-        for callback in self._on_remove_user_third_party_identifier_callbacks:
+        for (
+            callback
+        ) in self._module_api_callbacks.on_remove_user_third_party_identifier_callbacks:
            try:
                await callback(user_id, medium, address)
            except Exception as e:
--- a/synapse/events/utils.py
+++ b/synapse/events/utils.py
@@ -38,8 +38,7 @@ from synapse.api.constants import (
 )
 from synapse.api.errors import Codes, SynapseError
 from synapse.api.room_versions import RoomVersion
-from synapse.types import JsonDict
-from synapse.util.frozenutils import unfreeze
+from synapse.types import JsonDict, Requester

 from . import EventBase

@@ -317,8 +316,9 @@ class SerializeEventConfig:
    as_client_event: bool = True
    # Function to convert from federation format to client format
    event_format: Callable[[JsonDict], JsonDict] = format_event_for_client_v1
-    # ID of the user's auth token - used for namespacing of transaction IDs
-    token_id: Optional[int] = None
+    # The entity that requested the event. This is used to determine whether to include
+    # the transaction_id in the unsigned section of the event.
+    requester: Optional[Requester] = None
    # List of event fields to include. If empty, all fields will be returned.
    only_event_fields: Optional[List[str]] = None
    # Some events can have stripped room state stored in the `unsigned` field.
@@ -368,11 +368,24 @@ def serialize_event(
            e.unsigned["redacted_because"], time_now_ms, config=config
        )

-    if config.token_id is not None:
-        if config.token_id == getattr(e.internal_metadata, "token_id", None):
-            txn_id = getattr(e.internal_metadata, "txn_id", None)
-            if txn_id is not None:
-                d["unsigned"]["transaction_id"] = txn_id
+    # If we have a txn_id saved in the internal_metadata, we should include it in the
+    # unsigned section of the event if it was sent by the same session as the one
+    # requesting the event.
+    # There is a special case for guests, because they only have one access token
+    # without associated access_token_id, so we always include the txn_id for events
+    # they sent.
+    txn_id = getattr(e.internal_metadata, "txn_id", None)
+    if txn_id is not None and config.requester is not None:
+        event_token_id = getattr(e.internal_metadata, "token_id", None)
+        if config.requester.user.to_string() == e.sender and (
+            (
+                event_token_id is not None
+                and config.requester.access_token_id is not None
+                and event_token_id == config.requester.access_token_id
+            )
+            or config.requester.is_guest
+        ):
+            d["unsigned"]["transaction_id"] = txn_id

    # invite_room_state and knock_room_state are a list of stripped room state events
    # that are meant to provide metadata about a room to an invitee/knocker. They are
@@ -403,14 +416,6 @@ class EventClientSerializer:
    clients.
    """

-    def __init__(self, inhibit_replacement_via_edits: bool = False):
-        """
-        Args:
-            inhibit_replacement_via_edits: If this is set to True, then events are
-               never replaced by their edits.
-        """
-        self._inhibit_replacement_via_edits = inhibit_replacement_via_edits
-
    def serialize_event(
        self,
        event: Union[JsonDict, EventBase],
@@ -418,7 +423,6 @@ class EventClientSerializer:
        *,
        config: SerializeEventConfig = _DEFAULT_SERIALIZE_EVENT_CONFIG,
        bundle_aggregations: Optional[Dict[str, "BundledAggregations"]] = None,
-        apply_edits: bool = True,
    ) -> JsonDict:
        """Serializes a single event.

@@ -428,10 +432,7 @@ class EventClientSerializer:
            config: Event serialization config
            bundle_aggregations: A map from event_id to the aggregations to be bundled
               into the event.
-            apply_edits: Whether the content of the event should be modified to reflect
-               any replacement in `bundle_aggregations[<event_id>].replace`.
-               See also the `inhibit_replacement_via_edits` constructor arg: if that is
-               set to True, then this argument is ignored.
+
        Returns:
            The serialized event
        """
@@ -450,38 +451,10 @@ class EventClientSerializer:
                    config,
                    bundle_aggregations,
                    serialized_event,
-                    apply_edits=apply_edits,
                )

        return serialized_event

-    def _apply_edit(
-        self, orig_event: EventBase, serialized_event: JsonDict, edit: EventBase
-    ) -> None:
-        """Replace the content, preserving existing relations of the serialized event.
-
-        Args:
-            orig_event: The original event.
-            serialized_event: The original event, serialized. This is modified.
-            edit: The event which edits the above.
-        """
-
-        # Ensure we take copies of the edit content, otherwise we risk modifying
-        # the original event.
-        edit_content = edit.content.copy()
-
-        # Unfreeze the event content if necessary, so that we may modify it below
-        edit_content = unfreeze(edit_content)
-        serialized_event["content"] = edit_content.get("m.new_content", {})
-
-        # Check for existing relations
-        relates_to = orig_event.content.get("m.relates_to")
-        if relates_to:
-            # Keep the relations, ensuring we use a dict copy of the original
-            serialized_event["content"]["m.relates_to"] = relates_to.copy()
-        else:
-            serialized_event["content"].pop("m.relates_to", None)
-
    def _inject_bundled_aggregations(
        self,
        event: EventBase,
@@ -489,7 +462,6 @@ class EventClientSerializer:
        config: SerializeEventConfig,
        bundled_aggregations: Dict[str, "BundledAggregations"],
        serialized_event: JsonDict,
-        apply_edits: bool,
    ) -> None:
        """Potentially injects bundled aggregations into the unsigned portion of the serialized event.

@@ -504,9 +476,6 @@ class EventClientSerializer:
                While serializing the bundled aggregations this map may be searched
                again for additional events in a recursive manner.
            serialized_event: The serialized event which may be modified.
-            apply_edits: Whether the content of the event should be modified to reflect
-               any replacement in `aggregations.replace` (subject to the
-               `inhibit_replacement_via_edits` constructor arg).
        """

        # We have already checked that aggregations exist for this event.
@@ -522,11 +491,6 @@ class EventClientSerializer:
            ] = event_aggregations.references

        if event_aggregations.replace:
-            # If there is an edit, optionally apply it to the event.
-            edit = event_aggregations.replace
-            if apply_edits and not self._inhibit_replacement_via_edits:
-                self._apply_edit(event, serialized_event, edit)
-
            # Include information about it in the relations dict.
            #
            # Matrix spec v1.5 (https://spec.matrix.org/v1.5/client-server-api/#server-side-aggregation-of-mreplace-relationships)
@@ -534,10 +498,7 @@ class EventClientSerializer:
            # `sender` of the edit; however MSC3925 proposes extending it to the whole
            # of the edit, which is what we do here.
            serialized_aggregations[RelationTypes.REPLACE] = self.serialize_event(
-                edit,
-                time_now,
-                config=config,
-                apply_edits=False,
+                event_aggregations.replace, time_now, config=config
            )

        # Include any threaded replies to this event.
--- a/synapse/handlers/account_data.py
+++ b/synapse/handlers/account_data.py
@@ -14,7 +14,7 @@
 # limitations under the License.
 import logging
 import random
-from typing import TYPE_CHECKING, Awaitable, Callable, List, Optional, Tuple
+from typing import TYPE_CHECKING, List, Optional, Tuple

 from synapse.api.constants import AccountDataTypes
 from synapse.replication.http.account_data import (
@@ -33,10 +33,6 @@ if TYPE_CHECKING:

 logger = logging.getLogger(__name__)

-ON_ACCOUNT_DATA_UPDATED_CALLBACK = Callable[
-    [str, Optional[str], str, JsonDict], Awaitable
-]
-

 class AccountDataHandler:
    def __init__(self, hs: "HomeServer"):
@@ -60,16 +56,7 @@ class AccountDataHandler:
        self._remove_tag_client = ReplicationRemoveTagRestServlet.make_client(hs)
        self._account_data_writers = hs.config.worker.writers.account_data

-        self._on_account_data_updated_callbacks: List[
-            ON_ACCOUNT_DATA_UPDATED_CALLBACK
-        ] = []
-
-    def register_module_callbacks(
-        self, on_account_data_updated: Optional[ON_ACCOUNT_DATA_UPDATED_CALLBACK] = None
-    ) -> None:
-        """Register callbacks from modules."""
-        if on_account_data_updated is not None:
-            self._on_account_data_updated_callbacks.append(on_account_data_updated)
+        self._module_api_callbacks = hs.get_module_api_callbacks().account_data

    async def _notify_modules(
        self,
@@ -92,7 +79,7 @@ class AccountDataHandler:
            account_data_type: The type of the account data.
            content: The content that is now associated with this type.
        """
-        for callback in self._on_account_data_updated_callbacks:
+        for callback in self._module_api_callbacks.on_account_data_updated_callbacks:
            try:
                await callback(user_id, room_id, account_data_type, content)
            except Exception as e:
@@ -155,9 +142,6 @@ class AccountDataHandler:
            max_stream_id = await self._store.remove_account_data_for_room(
                user_id, room_id, account_data_type
            )
-            if max_stream_id is None:
-                # The referenced account data did not exist, so no delete occurred.
-                return None

            self._notifier.on_new_event(
                StreamKeyType.ACCOUNT_DATA, max_stream_id, users=[user_id]
@@ -230,9 +214,6 @@ class AccountDataHandler:
            max_stream_id = await self._store.remove_account_data_for_user(
                user_id, account_data_type
            )
-            if max_stream_id is None:
-                # The referenced account data did not exist, so no delete occurred.
-                return None

            self._notifier.on_new_event(
                StreamKeyType.ACCOUNT_DATA, max_stream_id, users=[user_id]
@@ -248,7 +229,6 @@ class AccountDataHandler:
                instance_name=random.choice(self._account_data_writers),
                user_id=user_id,
                account_data_type=account_data_type,
-                content={},
            )
            return response["max_stream_id"]

--- a/synapse/handlers/account_validity.py
+++ b/synapse/handlers/account_validity.py
@@ -15,9 +15,7 @@
 import email.mime.multipart
 import email.utils
 import logging
-from typing import TYPE_CHECKING, Awaitable, Callable, List, Optional, Tuple
-
-from twisted.web.http import Request
+from typing import TYPE_CHECKING, List, Optional, Tuple

 from synapse.api.errors import AuthError, StoreError, SynapseError
 from synapse.metrics.background_process_metrics import wrap_as_background_process
@@ -30,25 +28,17 @@ if TYPE_CHECKING:

 logger = logging.getLogger(__name__)

-# Types for callbacks to be registered via the module api
-IS_USER_EXPIRED_CALLBACK = Callable[[str], Awaitable[Optional[bool]]]
-ON_USER_REGISTRATION_CALLBACK = Callable[[str], Awaitable]
-# Temporary hooks to allow for a transition from `/_matrix/client` endpoints
-# to `/_synapse/client/account_validity`. See `register_account_validity_callbacks`.
-ON_LEGACY_SEND_MAIL_CALLBACK = Callable[[str], Awaitable]
-ON_LEGACY_RENEW_CALLBACK = Callable[[str], Awaitable[Tuple[bool, bool, int]]]
-ON_LEGACY_ADMIN_REQUEST = Callable[[Request], Awaitable]
-

 class AccountValidityHandler:
    def __init__(self, hs: "HomeServer"):
        self.hs = hs
        self.config = hs.config
-        self.store = self.hs.get_datastores().main
-        self.send_email_handler = self.hs.get_send_email_handler()
-        self.clock = self.hs.get_clock()
+        self.store = hs.get_datastores().main
+        self.send_email_handler = hs.get_send_email_handler()
+        self.clock = hs.get_clock()

-        self._app_name = self.hs.config.email.email_app_name
+        self._app_name = hs.config.email.email_app_name
+        self._module_api_callbacks = hs.get_module_api_callbacks().account_validity

        self._account_validity_enabled = (
            hs.config.account_validity.account_validity_enabled
@@ -78,69 +68,6 @@ class AccountValidityHandler:
            if hs.config.worker.run_background_tasks:
                self.clock.looping_call(self._send_renewal_emails, 30 * 60 * 1000)

-        self._is_user_expired_callbacks: List[IS_USER_EXPIRED_CALLBACK] = []
-        self._on_user_registration_callbacks: List[ON_USER_REGISTRATION_CALLBACK] = []
-        self._on_legacy_send_mail_callback: Optional[
-            ON_LEGACY_SEND_MAIL_CALLBACK
-        ] = None
-        self._on_legacy_renew_callback: Optional[ON_LEGACY_RENEW_CALLBACK] = None
-
-        # The legacy admin requests callback isn't a protected attribute because we need
-        # to access it from the admin servlet, which is outside of this handler.
-        self.on_legacy_admin_request_callback: Optional[ON_LEGACY_ADMIN_REQUEST] = None
-
-    def register_account_validity_callbacks(
-        self,
-        is_user_expired: Optional[IS_USER_EXPIRED_CALLBACK] = None,
-        on_user_registration: Optional[ON_USER_REGISTRATION_CALLBACK] = None,
-        on_legacy_send_mail: Optional[ON_LEGACY_SEND_MAIL_CALLBACK] = None,
-        on_legacy_renew: Optional[ON_LEGACY_RENEW_CALLBACK] = None,
-        on_legacy_admin_request: Optional[ON_LEGACY_ADMIN_REQUEST] = None,
-    ) -> None:
-        """Register callbacks from module for each hook."""
-        if is_user_expired is not None:
-            self._is_user_expired_callbacks.append(is_user_expired)
-
-        if on_user_registration is not None:
-            self._on_user_registration_callbacks.append(on_user_registration)
-
-        # The builtin account validity feature exposes 3 endpoints (send_mail, renew, and
-        # an admin one). As part of moving the feature into a module, we need to change
-        # the path from /_matrix/client/unstable/account_validity/... to
-        # /_synapse/client/account_validity, because:
-        #
-        #   * the feature isn't part of the Matrix spec thus shouldn't live under /_matrix
-        #   * the way we register servlets means that modules can't register resources
-        #     under /_matrix/client
-        #
-        # We need to allow for a transition period between the old and new endpoints
-        # in order to allow for clients to update (and for emails to be processed).
-        #
-        # Once the email-account-validity module is loaded, it will take control of account
-        # validity by moving the rows from our `account_validity` table into its own table.
-        #
-        # Therefore, we need to allow modules (in practice just the one implementing the
-        # email-based account validity) to temporarily hook into the legacy endpoints so we
-        # can route the traffic coming into the old endpoints into the module, which is
-        # why we have the following three temporary hooks.
-        if on_legacy_send_mail is not None:
-            if self._on_legacy_send_mail_callback is not None:
-                raise RuntimeError("Tried to register on_legacy_send_mail twice")
-
-            self._on_legacy_send_mail_callback = on_legacy_send_mail
-
-        if on_legacy_renew is not None:
-            if self._on_legacy_renew_callback is not None:
-                raise RuntimeError("Tried to register on_legacy_renew twice")
-
-            self._on_legacy_renew_callback = on_legacy_renew
-
-        if on_legacy_admin_request is not None:
-            if self.on_legacy_admin_request_callback is not None:
-                raise RuntimeError("Tried to register on_legacy_admin_request twice")
-
-            self.on_legacy_admin_request_callback = on_legacy_admin_request
-
    async def is_user_expired(self, user_id: str) -> bool:
        """Checks if a user has expired against third-party modules.

@@ -150,7 +77,7 @@ class AccountValidityHandler:
        Returns:
            Whether the user has expired.
        """
-        for callback in self._is_user_expired_callbacks:
+        for callback in self._module_api_callbacks.is_user_expired_callbacks:
            expired = await delay_cancellation(callback(user_id))
            if expired is not None:
                return expired
@@ -168,7 +95,7 @@ class AccountValidityHandler:
        Args:
            user_id: The ID of the newly registered user.
        """
-        for callback in self._on_user_registration_callbacks:
+        for callback in self._module_api_callbacks.on_user_registration_callbacks:
            await callback(user_id)

    @wrap_as_background_process("send_renewals")
@@ -198,8 +125,8 @@ class AccountValidityHandler:
        """
        # If a module supports sending a renewal email from here, do that, otherwise do
        # the legacy dance.
-        if self._on_legacy_send_mail_callback is not None:
-            await self._on_legacy_send_mail_callback(user_id)
+        if self._module_api_callbacks.on_legacy_send_mail_callback is not None:
+            await self._module_api_callbacks.on_legacy_send_mail_callback(user_id)
            return

        if not self._account_validity_renew_by_email_enabled:
@@ -336,8 +263,10 @@ class AccountValidityHandler:
        """
        # If a module supports triggering a renew from here, do that, otherwise do the
        # legacy dance.
-        if self._on_legacy_renew_callback is not None:
-            return await self._on_legacy_renew_callback(renewal_token)
+        if self._module_api_callbacks.on_legacy_renew_callback is not None:
+            return await self._module_api_callbacks.on_legacy_renew_callback(
+                renewal_token
+            )

        try:
            (
--- a/synapse/handlers/auth.py
+++ b/synapse/handlers/auth.py
@@ -65,6 +65,10 @@ from synapse.http.server import finish_request, respond_with_html
 from synapse.http.site import SynapseRequest
 from synapse.logging.context import defer_to_thread
 from synapse.metrics.background_process_metrics import run_as_background_process
+from synapse.module_api.callbacks.password_auth_provider_callbacks import (
+    CHECK_3PID_AUTH_CALLBACK,
+    ON_LOGGED_OUT_CALLBACK,
+)
 from synapse.storage.databases.main.registration import (
    LoginTokenExpired,
    LoginTokenLookupResult,
@@ -1096,7 +1100,7 @@ class AuthHandler:
        return self._password_enabled_for_login and self._password_localdb_enabled

    def get_supported_login_types(self) -> Iterable[str]:
-        """Get a the login types supported for the /login API
+        """Get the login types supported for the /login API

        By default this is just 'm.login.password' (unless password_enabled is
        False in the config file), but password auth providers can provide
@@ -1999,124 +2003,16 @@ def load_single_legacy_password_auth_provider(
    )


-CHECK_3PID_AUTH_CALLBACK = Callable[
-    [str, str, str],
-    Awaitable[
-        Optional[Tuple[str, Optional[Callable[["LoginResponse"], Awaitable[None]]]]]
-    ],
-]
-ON_LOGGED_OUT_CALLBACK = Callable[[str, Optional[str], str], Awaitable]
-CHECK_AUTH_CALLBACK = Callable[
-    [str, str, JsonDict],
-    Awaitable[
-        Optional[Tuple[str, Optional[Callable[["LoginResponse"], Awaitable[None]]]]]
-    ],
-]
-GET_USERNAME_FOR_REGISTRATION_CALLBACK = Callable[
-    [JsonDict, JsonDict],
-    Awaitable[Optional[str]],
-]
-GET_DISPLAYNAME_FOR_REGISTRATION_CALLBACK = Callable[
-    [JsonDict, JsonDict],
-    Awaitable[Optional[str]],
-]
-IS_3PID_ALLOWED_CALLBACK = Callable[[str, str, bool], Awaitable[bool]]
-
-
 class PasswordAuthProvider:
    """
    A class that the AuthHandler calls when authenticating users
    It allows modules to provide alternative methods for authentication
    """

-    def __init__(self) -> None:
-        # lists of callbacks
-        self.check_3pid_auth_callbacks: List[CHECK_3PID_AUTH_CALLBACK] = []
-        self.on_logged_out_callbacks: List[ON_LOGGED_OUT_CALLBACK] = []
-        self.get_username_for_registration_callbacks: List[
-            GET_USERNAME_FOR_REGISTRATION_CALLBACK
-        ] = []
-        self.get_displayname_for_registration_callbacks: List[
-            GET_DISPLAYNAME_FOR_REGISTRATION_CALLBACK
-        ] = []
-        self.is_3pid_allowed_callbacks: List[IS_3PID_ALLOWED_CALLBACK] = []
-
-        # Mapping from login type to login parameters
-        self._supported_login_types: Dict[str, Tuple[str, ...]] = {}
-
-        # Mapping from login type to auth checker callbacks
-        self.auth_checker_callbacks: Dict[str, List[CHECK_AUTH_CALLBACK]] = {}
-
-    def register_password_auth_provider_callbacks(
-        self,
-        check_3pid_auth: Optional[CHECK_3PID_AUTH_CALLBACK] = None,
-        on_logged_out: Optional[ON_LOGGED_OUT_CALLBACK] = None,
-        is_3pid_allowed: Optional[IS_3PID_ALLOWED_CALLBACK] = None,
-        auth_checkers: Optional[
-            Dict[Tuple[str, Tuple[str, ...]], CHECK_AUTH_CALLBACK]
-        ] = None,
-        get_username_for_registration: Optional[
-            GET_USERNAME_FOR_REGISTRATION_CALLBACK
-        ] = None,
-        get_displayname_for_registration: Optional[
-            GET_DISPLAYNAME_FOR_REGISTRATION_CALLBACK
-        ] = None,
-    ) -> None:
-        # Register check_3pid_auth callback
-        if check_3pid_auth is not None:
-            self.check_3pid_auth_callbacks.append(check_3pid_auth)
-
-        # register on_logged_out callback
-        if on_logged_out is not None:
-            self.on_logged_out_callbacks.append(on_logged_out)
-
-        if auth_checkers is not None:
-            # register a new supported login_type
-            # Iterate through all of the types being registered
-            for (login_type, fields), callback in auth_checkers.items():
-                # Note: fields may be empty here. This would allow a modules auth checker to
-                # be called with just 'login_type' and no password or other secrets
-
-                # Need to check that all the field names are strings or may get nasty errors later
-                for f in fields:
-                    if not isinstance(f, str):
-                        raise RuntimeError(
-                            "A module tried to register support for login type: %s with parameters %s"
-                            " but all parameter names must be strings"
-                            % (login_type, fields)
-                        )
-
-                # 2 modules supporting the same login type must expect the same fields
-                # e.g. 1 can't expect "pass" if the other expects "password"
-                # so throw an exception if that happens
-                if login_type not in self._supported_login_types.get(login_type, []):
-                    self._supported_login_types[login_type] = fields
-                else:
-                    fields_currently_supported = self._supported_login_types.get(
-                        login_type
-                    )
-                    if fields_currently_supported != fields:
-                        raise RuntimeError(
-                            "A module tried to register support for login type: %s with parameters %s"
-                            " but another module had already registered support for that type with parameters %s"
-                            % (login_type, fields, fields_currently_supported)
-                        )
-
-                # Add the new method to the list of auth_checker_callbacks for this login type
-                self.auth_checker_callbacks.setdefault(login_type, []).append(callback)
-
-        if get_username_for_registration is not None:
-            self.get_username_for_registration_callbacks.append(
-                get_username_for_registration,
-            )
-
-        if get_displayname_for_registration is not None:
-            self.get_displayname_for_registration_callbacks.append(
-                get_displayname_for_registration,
-            )
-
-        if is_3pid_allowed is not None:
-            self.is_3pid_allowed_callbacks.append(is_3pid_allowed)
+    def __init__(self, hs: "HomeServer") -> None:
+        self._module_api_callbacks = (
+            hs.get_module_api_callbacks().password_auth_provider
+        )

    def get_supported_login_types(self) -> Mapping[str, Iterable[str]]:
        """Get the login types supported by this password provider
@@ -2126,7 +2022,7 @@ class PasswordAuthProvider:
        to the /login API.
        """

-        return self._supported_login_types
+        return self._module_api_callbacks.supported_login_types

    async def check_auth(
        self, username: str, login_type: str, login_dict: JsonDict
@@ -2149,7 +2045,7 @@ class PasswordAuthProvider:

        # Go through all callbacks for the login type until one returns with a value
        # other than None (i.e. until a callback returns a success)
-        for callback in self.auth_checker_callbacks[login_type]:
+        for callback in self._module_api_callbacks.auth_checker_callbacks[login_type]:
            try:
                result = await delay_cancellation(
                    callback(username, login_type, login_dict)
@@ -2214,7 +2110,7 @@ class PasswordAuthProvider:
        # (user_id, callback_func), where callback_func should be run
        # after we've finished everything else

-        for callback in self.check_3pid_auth_callbacks:
+        for callback in self._module_api_callbacks.check_3pid_auth_callbacks:
            try:
                result = await delay_cancellation(callback(medium, address, password))
            except CancelledError:
@@ -2272,7 +2168,7 @@ class PasswordAuthProvider:
        self, user_id: str, device_id: Optional[str], access_token: str
    ) -> None:
        # call all of the on_logged_out callbacks
-        for callback in self.on_logged_out_callbacks:
+        for callback in self._module_api_callbacks.on_logged_out_callbacks:
            try:
                await callback(user_id, device_id, access_token)
            except Exception as e:
@@ -2297,7 +2193,9 @@ class PasswordAuthProvider:
            The localpart to use when registering this user, or None if no module
            returned a localpart.
        """
-        for callback in self.get_username_for_registration_callbacks:
+        for (
+            callback
+        ) in self._module_api_callbacks.get_username_for_registration_callbacks:
            try:
                res = await delay_cancellation(callback(uia_results, params))

@@ -2342,7 +2240,9 @@ class PasswordAuthProvider:
            A tuple which first element is the display name, and the second is an MXC URL
            to the user's avatar.
        """
-        for callback in self.get_displayname_for_registration_callbacks:
+        for (
+            callback
+        ) in self._module_api_callbacks.get_displayname_for_registration_callbacks:
            try:
                res = await delay_cancellation(callback(uia_results, params))

@@ -2385,7 +2285,7 @@ class PasswordAuthProvider:
        Returns:
            Whether the 3PID is allowed to be bound on this homeserver
        """
-        for callback in self.is_3pid_allowed_callbacks:
+        for callback in self._module_api_callbacks.is_3pid_allowed_callbacks:
            try:
                res = await delay_cancellation(callback(medium, address, registration))

--- a/synapse/handlers/e2e_keys.py
+++ b/synapse/handlers/e2e_keys.py
@@ -1301,6 +1301,20 @@ class E2eKeysHandler:

        return desired_key_data

+    async def is_cross_signing_set_up_for_user(self, user_id: str) -> bool:
+        """Checks if the user has cross-signing set up
+
+        Args:
+            user_id: The user to check
+
+        Returns:
+            True if the user has cross-signing set up, False otherwise
+        """
+        existing_master_key = await self.store.get_e2e_cross_signing_key(
+            user_id, "master"
+        )
+        return existing_master_key is not None
+

 def _check_cross_signing_key(
    key: JsonDict, user_id: str, key_type: str, signing_key: Optional[VerifyKey] = None
--- a/synapse/handlers/event_auth.py
+++ b/synapse/handlers/event_auth.py
@@ -63,19 +63,18 @@ class EventAuthHandler:
            self._store, event, batched_auth_events
        )
        auth_event_ids = event.auth_event_ids()
-        logger.info("Batched auth events %s", list(batched_auth_events.keys()))
-        logger.info("auth events %s", auth_event_ids)
+
        if batched_auth_events:
+            # Copy the batched auth events to avoid mutating them.
            auth_events_by_id = dict(batched_auth_events)
-            if set(auth_event_ids) - set(batched_auth_events):
-                logger.info("fetching %s", set(auth_event_ids) - set(batched_auth_events))
+            needed_auth_event_ids = set(auth_event_ids) - set(batched_auth_events)
+            if needed_auth_event_ids:
                auth_events_by_id.update(
-                    await self._store.get_events(
-                        set(auth_event_ids) - set(batched_auth_events)
-                    )
+                    await self._store.get_events(needed_auth_event_ids)
                )
        else:
            auth_events_by_id = await self._store.get_events(auth_event_ids)
+
        check_state_dependent_auth_rules(event, auth_events_by_id.values())

    def compute_auth_events(
--- a/synapse/handlers/events.py
+++ b/synapse/handlers/events.py
@@ -23,7 +23,7 @@ from synapse.events.utils import SerializeEventConfig
 from synapse.handlers.presence import format_user_presence_state
 from synapse.storage.databases.main.events_worker import EventRedactBehaviour
 from synapse.streams.config import PaginationConfig
-from synapse.types import JsonDict, UserID
+from synapse.types import JsonDict, Requester, UserID
 from synapse.visibility import filter_events_for_client

 if TYPE_CHECKING:
@@ -46,13 +46,12 @@ class EventStreamHandler:

    async def get_stream(
        self,
-        auth_user_id: str,
+        requester: Requester,
        pagin_config: PaginationConfig,
        timeout: int = 0,
        as_client_event: bool = True,
        affect_presence: bool = True,
        room_id: Optional[str] = None,
-        is_guest: bool = False,
    ) -> JsonDict:
        """Fetches the events stream for a given user."""

@@ -62,13 +61,12 @@ class EventStreamHandler:
                raise SynapseError(403, "This room has been blocked on this server")

        # send any outstanding server notices to the user.
-        await self._server_notices_sender.on_user_syncing(auth_user_id)
+        await self._server_notices_sender.on_user_syncing(requester.user.to_string())

-        auth_user = UserID.from_string(auth_user_id)
        presence_handler = self.hs.get_presence_handler()

        context = await presence_handler.user_syncing(
-            auth_user_id,
+            requester.user.to_string(),
            affect_presence=affect_presence,
            presence_state=PresenceState.ONLINE,
        )
@@ -82,10 +80,10 @@ class EventStreamHandler:
                timeout = random.randint(int(timeout * 0.9), int(timeout * 1.1))

            stream_result = await self.notifier.get_events_for(
-                auth_user,
+                requester.user,
                pagin_config,
                timeout,
-                is_guest=is_guest,
+                is_guest=requester.is_guest,
                explicit_room_id=room_id,
            )
            events = stream_result.events
@@ -102,7 +100,7 @@ class EventStreamHandler:
                    if event.membership != Membership.JOIN:
                        continue
                    # Send down presence.
-                    if event.state_key == auth_user_id:
+                    if event.state_key == requester.user.to_string():
                        # Send down presence for everyone in the room.
                        users: Iterable[str] = await self.store.get_users_in_room(
                            event.room_id
@@ -124,7 +122,9 @@ class EventStreamHandler:
            chunks = self._event_serializer.serialize_events(
                events,
                time_now,
-                config=SerializeEventConfig(as_client_event=as_client_event),
+                config=SerializeEventConfig(
+                    as_client_event=as_client_event, requester=requester
+                ),
            )

            chunk = {
--- a/synapse/handlers/initial_sync.py
+++ b/synapse/handlers/initial_sync.py
@@ -318,11 +318,9 @@ class InitialSyncHandler:
        )
        is_peeking = member_event_id is None

-        user_id = requester.user.to_string()
-
        if membership == Membership.JOIN:
            result = await self._room_initial_sync_joined(
-                user_id, room_id, pagin_config, membership, is_peeking
+                requester, room_id, pagin_config, membership, is_peeking
            )
        elif membership == Membership.LEAVE:
            # The member_event_id will always be available if membership is set
@@ -330,10 +328,16 @@ class InitialSyncHandler:
            assert member_event_id

            result = await self._room_initial_sync_parted(
-                user_id, room_id, pagin_config, membership, member_event_id, is_peeking
+                requester,
+                room_id,
+                pagin_config,
+                membership,
+                member_event_id,
+                is_peeking,
            )

        account_data_events = []
+        user_id = requester.user.to_string()
        tags = await self.store.get_tags_for_room(user_id, room_id)
        if tags:
            account_data_events.append(
@@ -350,7 +354,7 @@ class InitialSyncHandler:

    async def _room_initial_sync_parted(
        self,
-        user_id: str,
+        requester: Requester,
        room_id: str,
        pagin_config: PaginationConfig,
        membership: str,
@@ -369,13 +373,17 @@ class InitialSyncHandler:
        )

        messages = await filter_events_for_client(
-            self._storage_controllers, user_id, messages, is_peeking=is_peeking
+            self._storage_controllers,
+            requester.user.to_string(),
+            messages,
+            is_peeking=is_peeking,
        )

        start_token = StreamToken.START.copy_and_replace(StreamKeyType.ROOM, token)
        end_token = StreamToken.START.copy_and_replace(StreamKeyType.ROOM, stream_token)

        time_now = self.clock.time_msec()
+        serialize_options = SerializeEventConfig(requester=requester)

        return {
            "membership": membership,
@@ -383,14 +391,18 @@ class InitialSyncHandler:
            "messages": {
                "chunk": (
                    # Don't bundle aggregations as this is a deprecated API.
-                    self._event_serializer.serialize_events(messages, time_now)
+                    self._event_serializer.serialize_events(
+                        messages, time_now, config=serialize_options
+                    )
                ),
                "start": await start_token.to_string(self.store),
                "end": await end_token.to_string(self.store),
            },
            "state": (
                # Don't bundle aggregations as this is a deprecated API.
-                self._event_serializer.serialize_events(room_state.values(), time_now)
+                self._event_serializer.serialize_events(
+                    room_state.values(), time_now, config=serialize_options
+                )
            ),
            "presence": [],
            "receipts": [],
@@ -398,7 +410,7 @@ class InitialSyncHandler:

    async def _room_initial_sync_joined(
        self,
-        user_id: str,
+        requester: Requester,
        room_id: str,
        pagin_config: PaginationConfig,
        membership: str,
@@ -410,9 +422,12 @@ class InitialSyncHandler:

        # TODO: These concurrently
        time_now = self.clock.time_msec()
+        serialize_options = SerializeEventConfig(requester=requester)
        # Don't bundle aggregations as this is a deprecated API.
        state = self._event_serializer.serialize_events(
-            current_state.values(), time_now
+            current_state.values(),
+            time_now,
+            config=serialize_options,
        )

        now_token = self.hs.get_event_sources().get_current_token()
@@ -450,7 +465,10 @@ class InitialSyncHandler:
            if not receipts:
                return []

-            return ReceiptEventSource.filter_out_private_receipts(receipts, user_id)
+            return ReceiptEventSource.filter_out_private_receipts(
+                receipts,
+                requester.user.to_string(),
+            )

        presence, receipts, (messages, token) = await make_deferred_yieldable(
            gather_results(
@@ -469,20 +487,23 @@ class InitialSyncHandler:
        )

        messages = await filter_events_for_client(
-            self._storage_controllers, user_id, messages, is_peeking=is_peeking
+            self._storage_controllers,
+            requester.user.to_string(),
+            messages,
+            is_peeking=is_peeking,
        )

        start_token = now_token.copy_and_replace(StreamKeyType.ROOM, token)
        end_token = now_token

-        time_now = self.clock.time_msec()
-
        ret = {
            "room_id": room_id,
            "messages": {
                "chunk": (
                    # Don't bundle aggregations as this is a deprecated API.
-                    self._event_serializer.serialize_events(messages, time_now)
+                    self._event_serializer.serialize_events(
+                        messages, time_now, config=serialize_options
+                    )
                ),
                "start": await start_token.to_string(self.store),
                "end": await end_token.to_string(self.store),
--- a/synapse/handlers/message.py
+++ b/synapse/handlers/message.py
@@ -50,7 +50,7 @@ from synapse.event_auth import validate_event_for_room_version
 from synapse.events import EventBase, relation_from_event
 from synapse.events.builder import EventBuilder
 from synapse.events.snapshot import EventContext, UnpersistedEventContextBase
-from synapse.events.utils import maybe_upsert_event_field
+from synapse.events.utils import SerializeEventConfig, maybe_upsert_event_field
 from synapse.events.validator import EventValidator
 from synapse.handlers.directory import DirectoryHandler
 from synapse.logging import opentracing
@@ -245,8 +245,11 @@ class MessageHandler:
                )
                room_state = room_state_events[membership_event_id]

-        now = self.clock.time_msec()
-        events = self._event_serializer.serialize_events(room_state.values(), now)
+        events = self._event_serializer.serialize_events(
+            room_state.values(),
+            self.clock.time_msec(),
+            config=SerializeEventConfig(requester=requester),
+        )
        return events

    async def _user_can_see_state_at_event(
--- a/synapse/handlers/pagination.py
+++ b/synapse/handlers/pagination.py
@@ -579,7 +579,9 @@ class PaginationHandler:

        time_now = self.clock.time_msec()

-        serialize_options = SerializeEventConfig(as_client_event=as_client_event)
+        serialize_options = SerializeEventConfig(
+            as_client_event=as_client_event, requester=requester
+        )

        chunk = {
            "chunk": (
--- a/synapse/handlers/relations.py
+++ b/synapse/handlers/relations.py
@@ -20,6 +20,7 @@ import attr
 from synapse.api.constants import Direction, EventTypes, RelationTypes
 from synapse.api.errors import SynapseError
 from synapse.events import EventBase, relation_from_event
+from synapse.events.utils import SerializeEventConfig
 from synapse.logging.context import make_deferred_yieldable, run_in_background
 from synapse.logging.opentracing import trace
 from synapse.storage.databases.main.relations import ThreadsNextBatch, _RelatedEvent
@@ -151,16 +152,23 @@ class RelationsHandler:
        )

        now = self._clock.time_msec()
+        serialize_options = SerializeEventConfig(requester=requester)
        return_value: JsonDict = {
            "chunk": self._event_serializer.serialize_events(
-                events, now, bundle_aggregations=aggregations
+                events,
+                now,
+                bundle_aggregations=aggregations,
+                config=serialize_options,
            ),
        }
        if include_original_event:
            # Do not bundle aggregations when retrieving the original event because
            # we want the content before relations are applied to it.
            return_value["original_event"] = self._event_serializer.serialize_event(
-                event, now, bundle_aggregations=None
+                event,
+                now,
+                bundle_aggregations=None,
+                config=serialize_options,
            )

        if next_token:
--- a/synapse/handlers/room.py
+++ b/synapse/handlers/room.py
@@ -1123,6 +1123,8 @@ class RoomCreationHandler:
                event_dict,
                prev_event_ids=prev_event,
                depth=depth,
+                # Take a copy to ensure each event gets a unique copy of
+                # state_map since it is modified below.
                state_map=dict(state_map),
                for_batch=for_batch,
            )
--- a/synapse/handlers/room_member.py
+++ b/synapse/handlers/room_member.py
@@ -207,6 +207,7 @@ class RoomMemberHandler(metaclass=abc.ABCMeta):
    @abc.abstractmethod
    async def remote_knock(
        self,
+        requester: Requester,
        remote_room_hosts: List[str],
        room_id: str,
        user: UserID,
@@ -1073,7 +1074,7 @@ class RoomMemberHandler(metaclass=abc.ABCMeta):
                    )

                return await self.remote_knock(
-                    remote_room_hosts, room_id, target, content
+                    requester, remote_room_hosts, room_id, target, content
                )

        return await self._local_membership_update(
@@ -1984,6 +1985,7 @@ class RoomMemberMasterHandler(RoomMemberHandler):

    async def remote_knock(
        self,
+        requester: Requester,
        remote_room_hosts: List[str],
        room_id: str,
        user: UserID,
--- a/synapse/handlers/room_member_worker.py
+++ b/synapse/handlers/room_member_worker.py
@@ -113,6 +113,7 @@ class RoomMemberWorkerHandler(RoomMemberHandler):

    async def remote_knock(
        self,
+        requester: Requester,
        remote_room_hosts: List[str],
        room_id: str,
        user: UserID,
@@ -123,9 +124,10 @@ class RoomMemberWorkerHandler(RoomMemberHandler):
        Implements RoomMemberHandler.remote_knock
        """
        ret = await self._remote_knock_client(
+            requester=requester,
            remote_room_hosts=remote_room_hosts,
            room_id=room_id,
-            user=user,
+            user_id=user.to_string(),
            content=content,
        )
        return ret["event_id"], ret["stream_id"]
--- a/synapse/handlers/search.py
+++ b/synapse/handlers/search.py
@@ -23,7 +23,8 @@ from synapse.api.constants import EventTypes, Membership
 from synapse.api.errors import NotFoundError, SynapseError
 from synapse.api.filtering import Filter
 from synapse.events import EventBase
-from synapse.types import JsonDict, StrCollection, StreamKeyType, UserID
+from synapse.events.utils import SerializeEventConfig
+from synapse.types import JsonDict, Requester, StrCollection, StreamKeyType, UserID
 from synapse.types.state import StateFilter
 from synapse.visibility import filter_events_for_client

@@ -109,12 +110,12 @@ class SearchHandler:
        return historical_room_ids

    async def search(
-        self, user: UserID, content: JsonDict, batch: Optional[str] = None
+        self, requester: Requester, content: JsonDict, batch: Optional[str] = None
    ) -> JsonDict:
        """Performs a full text search for a user.

        Args:
-            user: The user performing the search.
+            requester: The user performing the search.
            content: Search parameters
            batch: The next_batch parameter. Used for pagination.

@@ -199,7 +200,7 @@ class SearchHandler:
            )

        return await self._search(
-            user,
+            requester,
            batch_group,
            batch_group_key,
            batch_token,
@@ -217,7 +218,7 @@ class SearchHandler:

    async def _search(
        self,
-        user: UserID,
+        requester: Requester,
        batch_group: Optional[str],
        batch_group_key: Optional[str],
        batch_token: Optional[str],
@@ -235,7 +236,7 @@ class SearchHandler:
        """Performs a full text search for a user.

        Args:
-            user: The user performing the search.
+            requester: The user performing the search.
            batch_group: Pagination information.
            batch_group_key: Pagination information.
            batch_token: Pagination information.
@@ -269,7 +270,7 @@ class SearchHandler:

        # TODO: Search through left rooms too
        rooms = await self.store.get_rooms_for_local_user_where_membership_is(
-            user.to_string(),
+            requester.user.to_string(),
            membership_list=[Membership.JOIN],
            # membership_list=[Membership.JOIN, Membership.LEAVE, Membership.Ban],
        )
@@ -303,13 +304,13 @@ class SearchHandler:

        if order_by == "rank":
            search_result, sender_group = await self._search_by_rank(
-                user, room_ids, search_term, keys, search_filter
+                requester.user, room_ids, search_term, keys, search_filter
            )
            # Unused return values for rank search.
            global_next_batch = None
        elif order_by == "recent":
            search_result, global_next_batch = await self._search_by_recent(
-                user,
+                requester.user,
                room_ids,
                search_term,
                keys,
@@ -334,7 +335,7 @@ class SearchHandler:
            assert after_limit is not None

            contexts = await self._calculate_event_contexts(
-                user,
+                requester.user,
                search_result.allowed_events,
                before_limit,
                after_limit,
@@ -363,27 +364,37 @@ class SearchHandler:
                # The returned events.
                search_result.allowed_events,
            ),
-            user.to_string(),
+            requester.user.to_string(),
        )

        # We're now about to serialize the events. We should not make any
        # blocking calls after this. Otherwise, the 'age' will be wrong.

        time_now = self.clock.time_msec()
+        serialize_options = SerializeEventConfig(requester=requester)

        for context in contexts.values():
            context["events_before"] = self._event_serializer.serialize_events(
-                context["events_before"], time_now, bundle_aggregations=aggregations
+                context["events_before"],
+                time_now,
+                bundle_aggregations=aggregations,
+                config=serialize_options,
            )
            context["events_after"] = self._event_serializer.serialize_events(
-                context["events_after"], time_now, bundle_aggregations=aggregations
+                context["events_after"],
+                time_now,
+                bundle_aggregations=aggregations,
+                config=serialize_options,
            )

        results = [
            {
                "rank": search_result.rank_map[e.event_id],
                "result": self._event_serializer.serialize_event(
-                    e, time_now, bundle_aggregations=aggregations
+                    e,
+                    time_now,
+                    bundle_aggregations=aggregations,
+                    config=serialize_options,
                ),
                "context": contexts.get(e.event_id, {}),
            }
@@ -398,7 +409,9 @@ class SearchHandler:

        if state_results:
            rooms_cat_res["state"] = {
-                room_id: self._event_serializer.serialize_events(state_events, time_now)
+                room_id: self._event_serializer.serialize_events(
+                    state_events, time_now, config=serialize_options
+                )
                for room_id, state_events in state_results.items()
            }

--- a/synapse/module_api/init.py
+++ b/synapse/module_api/init.py
@@ -39,56 +39,9 @@ from twisted.web.resource import Resource
 from synapse.api import errors
 from synapse.api.errors import SynapseError
 from synapse.events import EventBase
-from synapse.events.presence_router import (
-    GET_INTERESTED_USERS_CALLBACK,
-    GET_USERS_FOR_STATES_CALLBACK,
-    PresenceRouter,
-)
-from synapse.events.spamcheck import (
-    CHECK_EVENT_FOR_SPAM_CALLBACK,
-    CHECK_MEDIA_FILE_FOR_SPAM_CALLBACK,
-    CHECK_REGISTRATION_FOR_SPAM_CALLBACK,
-    CHECK_USERNAME_FOR_SPAM_CALLBACK,
-    SHOULD_DROP_FEDERATED_EVENT_CALLBACK,
-    USER_MAY_CREATE_ROOM_ALIAS_CALLBACK,
-    USER_MAY_CREATE_ROOM_CALLBACK,
-    USER_MAY_INVITE_CALLBACK,
-    USER_MAY_JOIN_ROOM_CALLBACK,
-    USER_MAY_PUBLISH_ROOM_CALLBACK,
-    USER_MAY_SEND_3PID_INVITE_CALLBACK,
-    SpamChecker,
-)
-from synapse.events.third_party_rules import (
-    CHECK_CAN_DEACTIVATE_USER_CALLBACK,
-    CHECK_CAN_SHUTDOWN_ROOM_CALLBACK,
-    CHECK_EVENT_ALLOWED_CALLBACK,
-    CHECK_THREEPID_CAN_BE_INVITED_CALLBACK,
-    CHECK_VISIBILITY_CAN_BE_MODIFIED_CALLBACK,
-    ON_ADD_USER_THIRD_PARTY_IDENTIFIER_CALLBACK,
-    ON_CREATE_ROOM_CALLBACK,
-    ON_NEW_EVENT_CALLBACK,
-    ON_PROFILE_UPDATE_CALLBACK,
-    ON_REMOVE_USER_THIRD_PARTY_IDENTIFIER_CALLBACK,
-    ON_THREEPID_BIND_CALLBACK,
-    ON_USER_DEACTIVATION_STATUS_CHANGED_CALLBACK,
-)
-from synapse.handlers.account_data import ON_ACCOUNT_DATA_UPDATED_CALLBACK
-from synapse.handlers.account_validity import (
-    IS_USER_EXPIRED_CALLBACK,
-    ON_LEGACY_ADMIN_REQUEST,
-    ON_LEGACY_RENEW_CALLBACK,
-    ON_LEGACY_SEND_MAIL_CALLBACK,
-    ON_USER_REGISTRATION_CALLBACK,
-)
-from synapse.handlers.auth import (
-    CHECK_3PID_AUTH_CALLBACK,
-    CHECK_AUTH_CALLBACK,
-    GET_DISPLAYNAME_FOR_REGISTRATION_CALLBACK,
-    GET_USERNAME_FOR_REGISTRATION_CALLBACK,
-    IS_3PID_ALLOWED_CALLBACK,
-    ON_LOGGED_OUT_CALLBACK,
-    AuthHandler,
-)
+from synapse.events.presence_router import PresenceRouter
+from synapse.events.spamcheck import SpamChecker
+from synapse.handlers.auth import AuthHandler
 from synapse.handlers.device import DeviceHandler
 from synapse.handlers.push_rules import RuleSpec, check_actions
 from synapse.http.client import SimpleHttpClient
@@ -105,13 +58,62 @@ from synapse.logging.context import (
    run_in_background,
 )
 from synapse.metrics.background_process_metrics import run_as_background_process
-from synapse.rest.client.login import LoginResponse
-from synapse.storage import DataStore
-from synapse.storage.background_updates import (
+from synapse.module_api.callbacks.account_data_callbacks import (
+    ON_ACCOUNT_DATA_UPDATED_CALLBACK,
+)
+from synapse.module_api.callbacks.account_validity_callbacks import (
+    IS_USER_EXPIRED_CALLBACK,
+    ON_LEGACY_ADMIN_REQUEST,
+    ON_LEGACY_RENEW_CALLBACK,
+    ON_LEGACY_SEND_MAIL_CALLBACK,
+    ON_USER_REGISTRATION_CALLBACK,
+)
+from synapse.module_api.callbacks.background_updater_callbacks import (
    DEFAULT_BATCH_SIZE_CALLBACK,
    MIN_BATCH_SIZE_CALLBACK,
    ON_UPDATE_CALLBACK,
 )
+from synapse.module_api.callbacks.password_auth_provider_callbacks import (
+    CHECK_3PID_AUTH_CALLBACK,
+    CHECK_AUTH_CALLBACK,
+    GET_DISPLAYNAME_FOR_REGISTRATION_CALLBACK,
+    GET_USERNAME_FOR_REGISTRATION_CALLBACK,
+    IS_3PID_ALLOWED_CALLBACK,
+    ON_LOGGED_OUT_CALLBACK,
+)
+from synapse.module_api.callbacks.presence_router_callbacks import (
+    GET_INTERESTED_USERS_CALLBACK,
+    GET_USERS_FOR_STATES_CALLBACK,
+)
+from synapse.module_api.callbacks.spam_checker_callbacks import (
+    CHECK_EVENT_FOR_SPAM_CALLBACK,
+    CHECK_MEDIA_FILE_FOR_SPAM_CALLBACK,
+    CHECK_REGISTRATION_FOR_SPAM_CALLBACK,
+    CHECK_USERNAME_FOR_SPAM_CALLBACK,
+    SHOULD_DROP_FEDERATED_EVENT_CALLBACK,
+    USER_MAY_CREATE_ROOM_ALIAS_CALLBACK,
+    USER_MAY_CREATE_ROOM_CALLBACK,
+    USER_MAY_INVITE_CALLBACK,
+    USER_MAY_JOIN_ROOM_CALLBACK,
+    USER_MAY_PUBLISH_ROOM_CALLBACK,
+    USER_MAY_SEND_3PID_INVITE_CALLBACK,
+)
+from synapse.module_api.callbacks.third_party_event_rules_callbacks import (
+    CHECK_CAN_DEACTIVATE_USER_CALLBACK,
+    CHECK_CAN_SHUTDOWN_ROOM_CALLBACK,
+    CHECK_EVENT_ALLOWED_CALLBACK,
+    CHECK_THREEPID_CAN_BE_INVITED_CALLBACK,
+    CHECK_VISIBILITY_CAN_BE_MODIFIED_CALLBACK,
+    ON_ADD_USER_THIRD_PARTY_IDENTIFIER_CALLBACK,
+    ON_CREATE_ROOM_CALLBACK,
+    ON_NEW_EVENT_CALLBACK,
+    ON_PROFILE_UPDATE_CALLBACK,
+    ON_REMOVE_USER_THIRD_PARTY_IDENTIFIER_CALLBACK,
+    ON_THREEPID_BIND_CALLBACK,
+    ON_USER_DEACTIVATION_STATUS_CHANGED_CALLBACK,
+)
+from synapse.rest.client.login import LoginResponse
+from synapse.storage import DataStore
 from synapse.storage.database import DatabasePool, LoggingTransaction
 from synapse.storage.databases.main.roommember import ProfileInfo
 from synapse.types import (
@@ -250,6 +252,7 @@ class ModuleApi:
        self._push_rules_handler = hs.get_push_rules_handler()
        self._device_handler = hs.get_device_handler()
        self.custom_template_dir = hs.config.server.custom_template_directory
+        self._callbacks = hs.get_module_api_callbacks()

        try:
            app_name = self._hs.config.email.email_app_name
@@ -270,13 +273,6 @@ class ModuleApi:
        self._public_room_list_manager = PublicRoomListManager(hs)
        self._account_data_manager = AccountDataManager(hs)

-        self._spam_checker = hs.get_spam_checker()
-        self._account_validity_handler = hs.get_account_validity_handler()
-        self._third_party_event_rules = hs.get_third_party_event_rules()
-        self._password_auth_provider = hs.get_password_auth_provider()
-        self._presence_router = hs.get_presence_router()
-        self._account_data_handler = hs.get_account_data_handler()
-
    #################################################################################
    # The following methods should only be called during the module's initialisation.

@@ -305,7 +301,7 @@ class ModuleApi:

        Added in Synapse v1.37.0.
        """
-        return self._spam_checker.register_callbacks(
+        return self._callbacks.spam_checker.register_callbacks(
            check_event_for_spam=check_event_for_spam,
            should_drop_federated_event=should_drop_federated_event,
            user_may_join_room=user_may_join_room,
@@ -332,7 +328,7 @@ class ModuleApi:

        Added in Synapse v1.39.0.
        """
-        return self._account_validity_handler.register_account_validity_callbacks(
+        return self._callbacks.account_validity.register_callbacks(
            is_user_expired=is_user_expired,
            on_user_registration=on_user_registration,
            on_legacy_send_mail=on_legacy_send_mail,
@@ -370,7 +366,7 @@ class ModuleApi:

        Added in Synapse v1.39.0.
        """
-        return self._third_party_event_rules.register_third_party_rules_callbacks(
+        return self._callbacks.third_party_event_rules.register_callbacks(
            check_event_allowed=check_event_allowed,
            on_create_room=on_create_room,
            check_threepid_can_be_invited=check_threepid_can_be_invited,
@@ -395,7 +391,7 @@ class ModuleApi:

        Added in Synapse v1.42.0.
        """
-        return self._presence_router.register_presence_router_callbacks(
+        return self._callbacks.presence_router.register_callbacks(
            get_users_for_states=get_users_for_states,
            get_interested_users=get_interested_users,
        )
@@ -420,7 +416,7 @@ class ModuleApi:

        Added in Synapse v1.46.0.
        """
-        return self._password_auth_provider.register_password_auth_provider_callbacks(
+        return self._callbacks.password_auth_provider.register_callbacks(
            check_3pid_auth=check_3pid_auth,
            on_logged_out=on_logged_out,
            is_3pid_allowed=is_3pid_allowed,
@@ -441,12 +437,11 @@ class ModuleApi:
        Added in Synapse v1.49.0.
        """

-        for db in self._hs.get_datastores().databases:
-            db.updates.register_update_controller_callbacks(
-                on_update=on_update,
-                default_batch_size=default_batch_size,
-                min_batch_size=min_batch_size,
-            )
+        self._callbacks.background_updater.register_callbacks(
+            on_update=on_update,
+            default_batch_size=default_batch_size,
+            min_batch_size=min_batch_size,
+        )

    def register_account_data_callbacks(
        self,
@@ -457,7 +452,7 @@ class ModuleApi:

        Added in Synapse 1.57.0.
        """
-        return self._account_data_handler.register_module_callbacks(
+        return self._callbacks.account_data.register_callbacks(
            on_account_data_updated=on_account_data_updated,
        )

--- a/synapse/module_api/callbacks/init.py
+++ b/synapse/module_api/callbacks/init.py
@@ -0,0 +1,36 @@
+# Copyright 2023 The Matrix.org Foundation C.I.C.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from .account_data_callbacks import AccountDataModuleApiCallbacks
+from .account_validity_callbacks import AccountValidityModuleApiCallbacks
+from .background_updater_callbacks import BackgroundUpdaterModuleApiCallbacks
+from .password_auth_provider_callbacks import PasswordAuthProviderModuleApiCallbacks
+from .presence_router_callbacks import PresenceRouterModuleApiCallbacks
+from .spam_checker_callbacks import SpamCheckerModuleApiCallbacks
+from .third_party_event_rules_callbacks import ThirdPartyEventRulesModuleApiCallbacks
+
+__all__ = [
+    "ModuleApiCallbacks",
+]
+
+
+class ModuleApiCallbacks:
+    def __init__(self) -> None:
+        self.account_data = AccountDataModuleApiCallbacks()
+        self.account_validity = AccountValidityModuleApiCallbacks()
+        self.background_updater = BackgroundUpdaterModuleApiCallbacks()
+        self.password_auth_provider = PasswordAuthProviderModuleApiCallbacks()
+        self.presence_router = PresenceRouterModuleApiCallbacks()
+        self.spam_checker = SpamCheckerModuleApiCallbacks()
+        self.third_party_event_rules = ThirdPartyEventRulesModuleApiCallbacks()
--- a/synapse/module_api/callbacks/account_data_callbacks.py
+++ b/synapse/module_api/callbacks/account_data_callbacks.py
@@ -0,0 +1,35 @@
+# Copyright 2015, 2016 OpenMarket Ltd
+# Copyright 2021, 2023 The Matrix.org Foundation C.I.C.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+from typing import Awaitable, Callable, List, Optional
+
+from synapse.types import JsonDict
+
+ON_ACCOUNT_DATA_UPDATED_CALLBACK = Callable[
+    [str, Optional[str], str, JsonDict], Awaitable
+]
+
+
+class AccountDataModuleApiCallbacks:
+    def __init__(self) -> None:
+        self.on_account_data_updated_callbacks: List[
+            ON_ACCOUNT_DATA_UPDATED_CALLBACK
+        ] = []
+
+    def register_callbacks(
+        self, on_account_data_updated: Optional[ON_ACCOUNT_DATA_UPDATED_CALLBACK] = None
+    ) -> None:
+        """Register callbacks from modules."""
+        if on_account_data_updated is not None:
+            self.on_account_data_updated_callbacks.append(on_account_data_updated)
--- a/synapse/module_api/callbacks/account_validity_callbacks.py
+++ b/synapse/module_api/callbacks/account_validity_callbacks.py
@@ -0,0 +1,93 @@
+# Copyright 2023 The Matrix.org Foundation C.I.C.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import logging
+from typing import Awaitable, Callable, List, Optional, Tuple
+
+from twisted.web.http import Request
+
+logger = logging.getLogger(__name__)
+
+# Types for callbacks to be registered via the module api
+IS_USER_EXPIRED_CALLBACK = Callable[[str], Awaitable[Optional[bool]]]
+ON_USER_REGISTRATION_CALLBACK = Callable[[str], Awaitable]
+# Temporary hooks to allow for a transition from `/_matrix/client` endpoints
+# to `/_synapse/client/account_validity`. See `register_account_validity_callbacks`.
+ON_LEGACY_SEND_MAIL_CALLBACK = Callable[[str], Awaitable]
+ON_LEGACY_RENEW_CALLBACK = Callable[[str], Awaitable[Tuple[bool, bool, int]]]
+ON_LEGACY_ADMIN_REQUEST = Callable[[Request], Awaitable]
+
+
+class AccountValidityModuleApiCallbacks:
+    def __init__(self) -> None:
+        self.is_user_expired_callbacks: List[IS_USER_EXPIRED_CALLBACK] = []
+        self.on_user_registration_callbacks: List[ON_USER_REGISTRATION_CALLBACK] = []
+        self.on_legacy_send_mail_callback: Optional[ON_LEGACY_SEND_MAIL_CALLBACK] = None
+        self.on_legacy_renew_callback: Optional[ON_LEGACY_RENEW_CALLBACK] = None
+
+        # The legacy admin requests callback isn't a protected attribute because we need
+        # to access it from the admin servlet, which is outside of this handler.
+        self.on_legacy_admin_request_callback: Optional[ON_LEGACY_ADMIN_REQUEST] = None
+
+    def register_callbacks(
+        self,
+        is_user_expired: Optional[IS_USER_EXPIRED_CALLBACK] = None,
+        on_user_registration: Optional[ON_USER_REGISTRATION_CALLBACK] = None,
+        on_legacy_send_mail: Optional[ON_LEGACY_SEND_MAIL_CALLBACK] = None,
+        on_legacy_renew: Optional[ON_LEGACY_RENEW_CALLBACK] = None,
+        on_legacy_admin_request: Optional[ON_LEGACY_ADMIN_REQUEST] = None,
+    ) -> None:
+        """Register callbacks from module for each hook."""
+        if is_user_expired is not None:
+            self.is_user_expired_callbacks.append(is_user_expired)
+
+        if on_user_registration is not None:
+            self.on_user_registration_callbacks.append(on_user_registration)
+
+        # The builtin account validity feature exposes 3 endpoints (send_mail, renew, and
+        # an admin one). As part of moving the feature into a module, we need to change
+        # the path from /_matrix/client/unstable/account_validity/... to
+        # /_synapse/client/account_validity, because:
+        #
+        #   * the feature isn't part of the Matrix spec thus shouldn't live under /_matrix
+        #   * the way we register servlets means that modules can't register resources
+        #     under /_matrix/client
+        #
+        # We need to allow for a transition period between the old and new endpoints
+        # in order to allow for clients to update (and for emails to be processed).
+        #
+        # Once the email-account-validity module is loaded, it will take control of account
+        # validity by moving the rows from our `account_validity` table into its own table.
+        #
+        # Therefore, we need to allow modules (in practice just the one implementing the
+        # email-based account validity) to temporarily hook into the legacy endpoints so we
+        # can route the traffic coming into the old endpoints into the module, which is
+        # why we have the following three temporary hooks.
+        if on_legacy_send_mail is not None:
+            if self.on_legacy_send_mail_callback is not None:
+                raise RuntimeError("Tried to register on_legacy_send_mail twice")
+
+            self.on_legacy_send_mail_callback = on_legacy_send_mail
+
+        if on_legacy_renew is not None:
+            if self.on_legacy_renew_callback is not None:
+                raise RuntimeError("Tried to register on_legacy_renew twice")
+
+            self.on_legacy_renew_callback = on_legacy_renew
+
+        if on_legacy_admin_request is not None:
+            if self.on_legacy_admin_request_callback is not None:
+                raise RuntimeError("Tried to register on_legacy_admin_request twice")
+
+            self.on_legacy_admin_request_callback = on_legacy_admin_request
--- a/synapse/module_api/callbacks/background_updater_callbacks.py
+++ b/synapse/module_api/callbacks/background_updater_callbacks.py
@@ -0,0 +1,54 @@
+# Copyright 2014-2016 OpenMarket Ltd
+# Copyright 2023 The Matrix.org Foundation C.I.C.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+import logging
+from typing import AsyncContextManager, Awaitable, Callable, Optional
+
+logger = logging.getLogger(__name__)
+
+ON_UPDATE_CALLBACK = Callable[[str, str, bool], AsyncContextManager[int]]
+DEFAULT_BATCH_SIZE_CALLBACK = Callable[[str, str], Awaitable[int]]
+MIN_BATCH_SIZE_CALLBACK = Callable[[str, str], Awaitable[int]]
+
+
+class BackgroundUpdaterModuleApiCallbacks:
+    def __init__(self) -> None:
+        self.on_update_callback: Optional[ON_UPDATE_CALLBACK] = None
+        self.default_batch_size_callback: Optional[DEFAULT_BATCH_SIZE_CALLBACK] = None
+        self.min_batch_size_callback: Optional[MIN_BATCH_SIZE_CALLBACK] = None
+
+    def register_callbacks(
+        self,
+        on_update: ON_UPDATE_CALLBACK,
+        default_batch_size: Optional[DEFAULT_BATCH_SIZE_CALLBACK] = None,
+        min_batch_size: Optional[DEFAULT_BATCH_SIZE_CALLBACK] = None,
+    ) -> None:
+        """Register callbacks from a module for each hook."""
+        if self.on_update_callback is not None:
+            logger.warning(
+                "More than one module tried to register callbacks for controlling"
+                " background updates. Only the callbacks registered by the first module"
+                " (in order of appearance in Synapse's configuration file) that tried to"
+                " do so will be called."
+            )
+
+            return
+
+        self.on_update_callback = on_update
+
+        if default_batch_size is not None:
+            self.default_batch_size_callback = default_batch_size
+
+        if min_batch_size is not None:
+            self.min_batch_size_callback = min_batch_size
--- a/synapse/module_api/callbacks/password_auth_provider_callbacks.py
+++ b/synapse/module_api/callbacks/password_auth_provider_callbacks.py
@@ -0,0 +1,138 @@
+# Copyright 2014 - 2016 OpenMarket Ltd
+# Copyright 2017 Vector Creations Ltd
+# Copyright 2019 - 2020, 2023 The Matrix.org Foundation C.I.C.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+import logging
+from typing import TYPE_CHECKING, Awaitable, Callable, Dict, List, Optional, Tuple
+
+from synapse.types import JsonDict
+
+if TYPE_CHECKING:
+    from synapse.module_api import LoginResponse
+
+logger = logging.getLogger(__name__)
+
+
+CHECK_3PID_AUTH_CALLBACK = Callable[
+    [str, str, str],
+    Awaitable[
+        Optional[Tuple[str, Optional[Callable[["LoginResponse"], Awaitable[None]]]]]
+    ],
+]
+ON_LOGGED_OUT_CALLBACK = Callable[[str, Optional[str], str], Awaitable]
+CHECK_AUTH_CALLBACK = Callable[
+    [str, str, JsonDict],
+    Awaitable[
+        Optional[Tuple[str, Optional[Callable[["LoginResponse"], Awaitable[None]]]]]
+    ],
+]
+GET_USERNAME_FOR_REGISTRATION_CALLBACK = Callable[
+    [JsonDict, JsonDict],
+    Awaitable[Optional[str]],
+]
+GET_DISPLAYNAME_FOR_REGISTRATION_CALLBACK = Callable[
+    [JsonDict, JsonDict],
+    Awaitable[Optional[str]],
+]
+IS_3PID_ALLOWED_CALLBACK = Callable[[str, str, bool], Awaitable[bool]]
+
+
+class PasswordAuthProviderModuleApiCallbacks:
+    def __init__(self) -> None:
+        # Mapping from login type to login parameters
+        self.supported_login_types: Dict[str, Tuple[str, ...]] = {}
+
+        self.check_3pid_auth_callbacks: List[CHECK_3PID_AUTH_CALLBACK] = []
+        self.on_logged_out_callbacks: List[ON_LOGGED_OUT_CALLBACK] = []
+        self.get_username_for_registration_callbacks: List[
+            GET_USERNAME_FOR_REGISTRATION_CALLBACK
+        ] = []
+        self.get_displayname_for_registration_callbacks: List[
+            GET_DISPLAYNAME_FOR_REGISTRATION_CALLBACK
+        ] = []
+        self.is_3pid_allowed_callbacks: List[IS_3PID_ALLOWED_CALLBACK] = []
+
+        # Mapping from login type to auth checker callbacks
+        self.auth_checker_callbacks: Dict[str, List[CHECK_AUTH_CALLBACK]] = {}
+
+    def register_callbacks(
+        self,
+        check_3pid_auth: Optional[CHECK_3PID_AUTH_CALLBACK] = None,
+        on_logged_out: Optional[ON_LOGGED_OUT_CALLBACK] = None,
+        is_3pid_allowed: Optional[IS_3PID_ALLOWED_CALLBACK] = None,
+        auth_checkers: Optional[
+            Dict[Tuple[str, Tuple[str, ...]], CHECK_AUTH_CALLBACK]
+        ] = None,
+        get_username_for_registration: Optional[
+            GET_USERNAME_FOR_REGISTRATION_CALLBACK
+        ] = None,
+        get_displayname_for_registration: Optional[
+            GET_DISPLAYNAME_FOR_REGISTRATION_CALLBACK
+        ] = None,
+    ) -> None:
+        # Register check_3pid_auth callback
+        if check_3pid_auth is not None:
+            self.check_3pid_auth_callbacks.append(check_3pid_auth)
+
+        # register on_logged_out callback
+        if on_logged_out is not None:
+            self.on_logged_out_callbacks.append(on_logged_out)
+
+        if auth_checkers is not None:
+            # register a new supported login_type
+            # Iterate through all of the types being registered
+            for (login_type, fields), callback in auth_checkers.items():
+                # Note: fields may be empty here. This would allow a modules auth checker to
+                # be called with just 'login_type' and no password or other secrets
+
+                # Need to check that all the field names are strings or may get nasty errors later
+                for f in fields:
+                    if not isinstance(f, str):
+                        raise RuntimeError(
+                            "A module tried to register support for login type: %s with parameters %s"
+                            " but all parameter names must be strings"
+                            % (login_type, fields)
+                        )
+
+                # 2 modules supporting the same login type must expect the same fields
+                # e.g. 1 can't expect "pass" if the other expects "password"
+                # so throw an exception if that happens
+                if login_type not in self.supported_login_types.get(login_type, []):
+                    self.supported_login_types[login_type] = fields
+                else:
+                    fields_currently_supported = self.supported_login_types.get(
+                        login_type
+                    )
+                    if fields_currently_supported != fields:
+                        raise RuntimeError(
+                            "A module tried to register support for login type: %s with parameters %s"
+                            " but another module had already registered support for that type with parameters %s"
+                            % (login_type, fields, fields_currently_supported)
+                        )
+
+                # Add the new method to the list of auth_checker_callbacks for this login type
+                self.auth_checker_callbacks.setdefault(login_type, []).append(callback)
+
+        if get_username_for_registration is not None:
+            self.get_username_for_registration_callbacks.append(
+                get_username_for_registration,
+            )
+
+        if get_displayname_for_registration is not None:
+            self.get_displayname_for_registration_callbacks.append(
+                get_displayname_for_registration,
+            )
+
+        if is_3pid_allowed is not None:
+            self.is_3pid_allowed_callbacks.append(is_3pid_allowed)
--- a/synapse/module_api/callbacks/presence_router_callbacks.py
+++ b/synapse/module_api/callbacks/presence_router_callbacks.py
@@ -0,0 +1,122 @@
+# Copyright 2021, 2023 The Matrix.org Foundation C.I.C.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+from typing import (
+    TYPE_CHECKING,
+    Any,
+    Awaitable,
+    Callable,
+    Dict,
+    Iterable,
+    List,
+    Optional,
+    Set,
+    TypeVar,
+    Union,
+)
+
+from typing_extensions import ParamSpec
+
+from synapse.api.presence import UserPresenceState
+from synapse.util.async_helpers import maybe_awaitable
+
+if TYPE_CHECKING:
+    from synapse.server import HomeServer
+
+GET_USERS_FOR_STATES_CALLBACK = Callable[
+    [Iterable[UserPresenceState]], Awaitable[Dict[str, Set[UserPresenceState]]]
+]
+# This must either return a set of strings or the constant PresenceRouter.ALL_USERS.
+GET_INTERESTED_USERS_CALLBACK = Callable[[str], Awaitable[Union[Set[str], str]]]
+
+
+P = ParamSpec("P")
+R = TypeVar("R")
+
+
+def load_legacy_presence_router(hs: "HomeServer") -> None:
+    """Wrapper that loads a presence router module configured using the old
+    configuration, and registers the hooks they implement.
+    """
+
+    if hs.config.server.presence_router_module_class is None:
+        return
+
+    module = hs.config.server.presence_router_module_class
+    config = hs.config.server.presence_router_config
+    api = hs.get_module_api()
+
+    presence_router = module(config=config, module_api=api)
+
+    # The known hooks. If a module implements a method which name appears in this set,
+    # we'll want to register it.
+    presence_router_methods = {
+        "get_users_for_states",
+        "get_interested_users",
+    }
+
+    # All methods that the module provides should be async, but this wasn't enforced
+    # in the old module system, so we wrap them if needed
+    def async_wrapper(
+        f: Optional[Callable[P, R]]
+    ) -> Optional[Callable[P, Awaitable[R]]]:
+        # f might be None if the callback isn't implemented by the module. In this
+        # case we don't want to register a callback at all so we return None.
+        if f is None:
+            return None
+
+        def run(*args: P.args, **kwargs: P.kwargs) -> Awaitable[R]:
+            # Assertion required because mypy can't prove we won't change `f`
+            # back to `None`. See
+            # https://mypy.readthedocs.io/en/latest/common_issues.html#narrowing-and-inner-functions
+            assert f is not None
+
+            return maybe_awaitable(f(*args, **kwargs))
+
+        return run
+
+    # Register the hooks through the module API.
+    hooks: Dict[str, Optional[Callable[..., Any]]] = {
+        hook: async_wrapper(getattr(presence_router, hook, None))
+        for hook in presence_router_methods
+    }
+
+    api.register_presence_router_callbacks(**hooks)
+
+
+class PresenceRouterModuleApiCallbacks:
+    def __init__(self) -> None:
+        # Initially there are no callbacks
+        self.get_users_for_states_callbacks: List[GET_USERS_FOR_STATES_CALLBACK] = []
+        self.get_interested_users_callbacks: List[GET_INTERESTED_USERS_CALLBACK] = []
+
+    def register_callbacks(
+        self,
+        get_users_for_states: Optional[GET_USERS_FOR_STATES_CALLBACK] = None,
+        get_interested_users: Optional[GET_INTERESTED_USERS_CALLBACK] = None,
+    ) -> None:
+        # PresenceRouter modules are required to implement both of these methods
+        # or neither of them as they are assumed to act in a complementary manner
+        paired_methods = [get_users_for_states, get_interested_users]
+        if paired_methods.count(None) == 1:
+            raise RuntimeError(
+                "PresenceRouter modules must register neither or both of the paired callbacks: "
+                "[get_users_for_states, get_interested_users]"
+            )
+
+        # Append the methods provided to the lists of callbacks
+        if get_users_for_states is not None:
+            self.get_users_for_states_callbacks.append(get_users_for_states)
+
+        if get_interested_users is not None:
+            self.get_interested_users_callbacks.append(get_interested_users)
--- a/synapse/module_api/callbacks/spam_checker_callbacks.py
+++ b/synapse/module_api/callbacks/spam_checker_callbacks.py
@@ -0,0 +1,373 @@
+# Copyright 2017 New Vector Ltd
+# Copyright 2019, 2023 The Matrix.org Foundation C.I.C.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+import inspect
+import logging
+from typing import (
+    TYPE_CHECKING,
+    Any,
+    Awaitable,
+    Callable,
+    Collection,
+    List,
+    Optional,
+    Tuple,
+    Union,
+)
+
+# `Literal` appears with Python 3.8.
+from typing_extensions import Literal
+
+import synapse
+from synapse.api.errors import Codes
+from synapse.rest.media.v1._base import FileInfo
+from synapse.rest.media.v1.media_storage import ReadableFileWrapper
+from synapse.spam_checker_api import RegistrationBehaviour
+from synapse.types import JsonDict, RoomAlias, UserProfile
+from synapse.util.async_helpers import maybe_awaitable
+
+if TYPE_CHECKING:
+    import synapse.events
+    import synapse.server
+
+logger = logging.getLogger(__name__)
+
+
+CHECK_EVENT_FOR_SPAM_CALLBACK = Callable[
+    ["synapse.events.EventBase"],
+    Awaitable[
+        Union[
+            str,
+            Codes,
+            # Highly experimental, not officially part of the spamchecker API, may
+            # disappear without warning depending on the results of ongoing
+            # experiments.
+            # Use this to return additional information as part of an error.
+            Tuple[Codes, JsonDict],
+            # Deprecated
+            bool,
+        ]
+    ],
+]
+SHOULD_DROP_FEDERATED_EVENT_CALLBACK = Callable[
+    ["synapse.events.EventBase"],
+    Awaitable[Union[bool, str]],
+]
+USER_MAY_JOIN_ROOM_CALLBACK = Callable[
+    [str, str, bool],
+    Awaitable[
+        Union[
+            Literal["NOT_SPAM"],
+            Codes,
+            # Highly experimental, not officially part of the spamchecker API, may
+            # disappear without warning depending on the results of ongoing
+            # experiments.
+            # Use this to return additional information as part of an error.
+            Tuple[Codes, JsonDict],
+            # Deprecated
+            bool,
+        ]
+    ],
+]
+USER_MAY_INVITE_CALLBACK = Callable[
+    [str, str, str],
+    Awaitable[
+        Union[
+            Literal["NOT_SPAM"],
+            Codes,
+            # Highly experimental, not officially part of the spamchecker API, may
+            # disappear without warning depending on the results of ongoing
+            # experiments.
+            # Use this to return additional information as part of an error.
+            Tuple[Codes, JsonDict],
+            # Deprecated
+            bool,
+        ]
+    ],
+]
+USER_MAY_SEND_3PID_INVITE_CALLBACK = Callable[
+    [str, str, str, str],
+    Awaitable[
+        Union[
+            Literal["NOT_SPAM"],
+            Codes,
+            # Highly experimental, not officially part of the spamchecker API, may
+            # disappear without warning depending on the results of ongoing
+            # experiments.
+            # Use this to return additional information as part of an error.
+            Tuple[Codes, JsonDict],
+            # Deprecated
+            bool,
+        ]
+    ],
+]
+USER_MAY_CREATE_ROOM_CALLBACK = Callable[
+    [str],
+    Awaitable[
+        Union[
+            Literal["NOT_SPAM"],
+            Codes,
+            # Highly experimental, not officially part of the spamchecker API, may
+            # disappear without warning depending on the results of ongoing
+            # experiments.
+            # Use this to return additional information as part of an error.
+            Tuple[Codes, JsonDict],
+            # Deprecated
+            bool,
+        ]
+    ],
+]
+USER_MAY_CREATE_ROOM_ALIAS_CALLBACK = Callable[
+    [str, RoomAlias],
+    Awaitable[
+        Union[
+            Literal["NOT_SPAM"],
+            Codes,
+            # Highly experimental, not officially part of the spamchecker API, may
+            # disappear without warning depending on the results of ongoing
+            # experiments.
+            # Use this to return additional information as part of an error.
+            Tuple[Codes, JsonDict],
+            # Deprecated
+            bool,
+        ]
+    ],
+]
+USER_MAY_PUBLISH_ROOM_CALLBACK = Callable[
+    [str, str],
+    Awaitable[
+        Union[
+            Literal["NOT_SPAM"],
+            Codes,
+            # Highly experimental, not officially part of the spamchecker API, may
+            # disappear without warning depending on the results of ongoing
+            # experiments.
+            # Use this to return additional information as part of an error.
+            Tuple[Codes, JsonDict],
+            # Deprecated
+            bool,
+        ]
+    ],
+]
+CHECK_USERNAME_FOR_SPAM_CALLBACK = Callable[[UserProfile], Awaitable[bool]]
+LEGACY_CHECK_REGISTRATION_FOR_SPAM_CALLBACK = Callable[
+    [
+        Optional[dict],
+        Optional[str],
+        Collection[Tuple[str, str]],
+    ],
+    Awaitable[RegistrationBehaviour],
+]
+CHECK_REGISTRATION_FOR_SPAM_CALLBACK = Callable[
+    [
+        Optional[dict],
+        Optional[str],
+        Collection[Tuple[str, str]],
+        Optional[str],
+    ],
+    Awaitable[RegistrationBehaviour],
+]
+CHECK_MEDIA_FILE_FOR_SPAM_CALLBACK = Callable[
+    [ReadableFileWrapper, FileInfo],
+    Awaitable[
+        Union[
+            Literal["NOT_SPAM"],
+            Codes,
+            # Highly experimental, not officially part of the spamchecker API, may
+            # disappear without warning depending on the results of ongoing
+            # experiments.
+            # Use this to return additional information as part of an error.
+            Tuple[Codes, JsonDict],
+            # Deprecated
+            bool,
+        ]
+    ],
+]
+
+
+def load_legacy_spam_checkers(hs: "synapse.server.HomeServer") -> None:
+    """Wrapper that loads spam checkers configured using the old configuration, and
+    registers the spam checker hooks they implement.
+    """
+    spam_checkers: List[Any] = []
+    api = hs.get_module_api()
+    for module, config in hs.config.spamchecker.spam_checkers:
+        # Older spam checkers don't accept the `api` argument, so we
+        # try and detect support.
+        spam_args = inspect.getfullargspec(module)
+        if "api" in spam_args.args:
+            spam_checkers.append(module(config=config, api=api))
+        else:
+            spam_checkers.append(module(config=config))
+
+    # The known spam checker hooks. If a spam checker module implements a method
+    # which name appears in this set, we'll want to register it.
+    spam_checker_methods = {
+        "check_event_for_spam",
+        "user_may_invite",
+        "user_may_create_room",
+        "user_may_create_room_alias",
+        "user_may_publish_room",
+        "check_username_for_spam",
+        "check_registration_for_spam",
+        "check_media_file_for_spam",
+    }
+
+    for spam_checker in spam_checkers:
+        # Methods on legacy spam checkers might not be async, so we wrap them around a
+        # wrapper that will call maybe_awaitable on the result.
+        def async_wrapper(f: Optional[Callable]) -> Optional[Callable[..., Awaitable]]:
+            # f might be None if the callback isn't implemented by the module. In this
+            # case we don't want to register a callback at all so we return None.
+            if f is None:
+                return None
+
+            wrapped_func = f
+
+            if f.__name__ == "check_registration_for_spam":
+                checker_args = inspect.signature(f)
+                if len(checker_args.parameters) == 3:
+                    # Backwards compatibility; some modules might implement a hook that
+                    # doesn't expect a 4th argument. In this case, wrap it in a function
+                    # that gives it only 3 arguments and drops the auth_provider_id on
+                    # the floor.
+                    def wrapper(
+                        email_threepid: Optional[dict],
+                        username: Optional[str],
+                        request_info: Collection[Tuple[str, str]],
+                        auth_provider_id: Optional[str],
+                    ) -> Union[Awaitable[RegistrationBehaviour], RegistrationBehaviour]:
+                        # Assertion required because mypy can't prove we won't
+                        # change `f` back to `None`. See
+                        # https://mypy.readthedocs.io/en/latest/common_issues.html#narrowing-and-inner-functions
+                        assert f is not None
+
+                        return f(
+                            email_threepid,
+                            username,
+                            request_info,
+                        )
+
+                    wrapped_func = wrapper
+                elif len(checker_args.parameters) != 4:
+                    raise RuntimeError(
+                        "Bad signature for callback check_registration_for_spam",
+                    )
+
+            def run(*args: Any, **kwargs: Any) -> Awaitable:
+                # Assertion required because mypy can't prove we won't change `f`
+                # back to `None`. See
+                # https://mypy.readthedocs.io/en/latest/common_issues.html#narrowing-and-inner-functions
+                assert wrapped_func is not None
+
+                return maybe_awaitable(wrapped_func(*args, **kwargs))
+
+            return run
+
+        # Register the hooks through the module API.
+        hooks = {
+            hook: async_wrapper(getattr(spam_checker, hook, None))
+            for hook in spam_checker_methods
+        }
+
+        api.register_spam_checker_callbacks(**hooks)
+
+
+class SpamCheckerModuleApiCallbacks:
+    def __init__(self) -> None:
+        self.check_event_for_spam_callbacks: List[CHECK_EVENT_FOR_SPAM_CALLBACK] = []
+        self.should_drop_federated_event_callbacks: List[
+            SHOULD_DROP_FEDERATED_EVENT_CALLBACK
+        ] = []
+        self.user_may_join_room_callbacks: List[USER_MAY_JOIN_ROOM_CALLBACK] = []
+        self.user_may_invite_callbacks: List[USER_MAY_INVITE_CALLBACK] = []
+        self.user_may_send_3pid_invite_callbacks: List[
+            USER_MAY_SEND_3PID_INVITE_CALLBACK
+        ] = []
+        self.user_may_create_room_callbacks: List[USER_MAY_CREATE_ROOM_CALLBACK] = []
+        self.user_may_create_room_alias_callbacks: List[
+            USER_MAY_CREATE_ROOM_ALIAS_CALLBACK
+        ] = []
+        self.user_may_publish_room_callbacks: List[USER_MAY_PUBLISH_ROOM_CALLBACK] = []
+        self.check_username_for_spam_callbacks: List[
+            CHECK_USERNAME_FOR_SPAM_CALLBACK
+        ] = []
+        self.check_registration_for_spam_callbacks: List[
+            CHECK_REGISTRATION_FOR_SPAM_CALLBACK
+        ] = []
+        self.check_media_file_for_spam_callbacks: List[
+            CHECK_MEDIA_FILE_FOR_SPAM_CALLBACK
+        ] = []
+
+    def register_callbacks(
+        self,
+        check_event_for_spam: Optional[CHECK_EVENT_FOR_SPAM_CALLBACK] = None,
+        should_drop_federated_event: Optional[
+            SHOULD_DROP_FEDERATED_EVENT_CALLBACK
+        ] = None,
+        user_may_join_room: Optional[USER_MAY_JOIN_ROOM_CALLBACK] = None,
+        user_may_invite: Optional[USER_MAY_INVITE_CALLBACK] = None,
+        user_may_send_3pid_invite: Optional[USER_MAY_SEND_3PID_INVITE_CALLBACK] = None,
+        user_may_create_room: Optional[USER_MAY_CREATE_ROOM_CALLBACK] = None,
+        user_may_create_room_alias: Optional[
+            USER_MAY_CREATE_ROOM_ALIAS_CALLBACK
+        ] = None,
+        user_may_publish_room: Optional[USER_MAY_PUBLISH_ROOM_CALLBACK] = None,
+        check_username_for_spam: Optional[CHECK_USERNAME_FOR_SPAM_CALLBACK] = None,
+        check_registration_for_spam: Optional[
+            CHECK_REGISTRATION_FOR_SPAM_CALLBACK
+        ] = None,
+        check_media_file_for_spam: Optional[CHECK_MEDIA_FILE_FOR_SPAM_CALLBACK] = None,
+    ) -> None:
+        """Register callbacks from module for each hook."""
+        if check_event_for_spam is not None:
+            self.check_event_for_spam_callbacks.append(check_event_for_spam)
+
+        if should_drop_federated_event is not None:
+            self.should_drop_federated_event_callbacks.append(
+                should_drop_federated_event
+            )
+
+        if user_may_join_room is not None:
+            self.user_may_join_room_callbacks.append(user_may_join_room)
+
+        if user_may_invite is not None:
+            self.user_may_invite_callbacks.append(user_may_invite)
+
+        if user_may_send_3pid_invite is not None:
+            self.user_may_send_3pid_invite_callbacks.append(
+                user_may_send_3pid_invite,
+            )
+
+        if user_may_create_room is not None:
+            self.user_may_create_room_callbacks.append(user_may_create_room)
+
+        if user_may_create_room_alias is not None:
+            self.user_may_create_room_alias_callbacks.append(
+                user_may_create_room_alias,
+            )
+
+        if user_may_publish_room is not None:
+            self.user_may_publish_room_callbacks.append(user_may_publish_room)
+
+        if check_username_for_spam is not None:
+            self.check_username_for_spam_callbacks.append(check_username_for_spam)
+
+        if check_registration_for_spam is not None:
+            self.check_registration_for_spam_callbacks.append(
+                check_registration_for_spam,
+            )
+
+        if check_media_file_for_spam is not None:
+            self.check_media_file_for_spam_callbacks.append(check_media_file_for_spam)
--- a/synapse/module_api/callbacks/third_party_event_rules_callbacks.py
+++ b/synapse/module_api/callbacks/third_party_event_rules_callbacks.py
@@ -0,0 +1,238 @@
+# Copyright 2019, 2023 The Matrix.org Foundation C.I.C.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+import logging
+from typing import TYPE_CHECKING, Any, Awaitable, Callable, List, Optional, Tuple
+
+from synapse.api.errors import SynapseError
+from synapse.events import EventBase
+from synapse.storage.roommember import ProfileInfo
+from synapse.types import Requester, StateMap
+from synapse.util.async_helpers import maybe_awaitable
+
+if TYPE_CHECKING:
+    from synapse.server import HomeServer
+
+logger = logging.getLogger(__name__)
+
+CHECK_EVENT_ALLOWED_CALLBACK = Callable[
+    [EventBase, StateMap[EventBase]], Awaitable[Tuple[bool, Optional[dict]]]
+]
+ON_CREATE_ROOM_CALLBACK = Callable[[Requester, dict, bool], Awaitable]
+CHECK_THREEPID_CAN_BE_INVITED_CALLBACK = Callable[
+    [str, str, StateMap[EventBase]], Awaitable[bool]
+]
+CHECK_VISIBILITY_CAN_BE_MODIFIED_CALLBACK = Callable[
+    [str, StateMap[EventBase], str], Awaitable[bool]
+]
+ON_NEW_EVENT_CALLBACK = Callable[[EventBase, StateMap[EventBase]], Awaitable]
+CHECK_CAN_SHUTDOWN_ROOM_CALLBACK = Callable[[str, str], Awaitable[bool]]
+CHECK_CAN_DEACTIVATE_USER_CALLBACK = Callable[[str, bool], Awaitable[bool]]
+ON_PROFILE_UPDATE_CALLBACK = Callable[[str, ProfileInfo, bool, bool], Awaitable]
+ON_USER_DEACTIVATION_STATUS_CHANGED_CALLBACK = Callable[[str, bool, bool], Awaitable]
+ON_THREEPID_BIND_CALLBACK = Callable[[str, str, str], Awaitable]
+ON_ADD_USER_THIRD_PARTY_IDENTIFIER_CALLBACK = Callable[[str, str, str], Awaitable]
+ON_REMOVE_USER_THIRD_PARTY_IDENTIFIER_CALLBACK = Callable[[str, str, str], Awaitable]
+
+
+def load_legacy_third_party_event_rules(hs: "HomeServer") -> None:
+    """Wrapper that loads a third party event rules module configured using the old
+    configuration, and registers the hooks they implement.
+    """
+    if hs.config.thirdpartyrules.third_party_event_rules is None:
+        return
+
+    module, config = hs.config.thirdpartyrules.third_party_event_rules
+
+    api = hs.get_module_api()
+    third_party_rules = module(config=config, module_api=api)
+
+    # The known hooks. If a module implements a method which name appears in this set,
+    # we'll want to register it.
+    third_party_event_rules_methods = {
+        "check_event_allowed",
+        "on_create_room",
+        "check_threepid_can_be_invited",
+        "check_visibility_can_be_modified",
+    }
+
+    def async_wrapper(f: Optional[Callable]) -> Optional[Callable[..., Awaitable]]:
+        # f might be None if the callback isn't implemented by the module. In this
+        # case we don't want to register a callback at all so we return None.
+        if f is None:
+            return None
+
+        # We return a separate wrapper for these methods because, in order to wrap them
+        # correctly, we need to await its result. Therefore it doesn't make a lot of
+        # sense to make it go through the run() wrapper.
+        if f.__name__ == "check_event_allowed":
+            # We need to wrap check_event_allowed because its old form would return either
+            # a boolean or a dict, but now we want to return the dict separately from the
+            # boolean.
+            async def wrap_check_event_allowed(
+                event: EventBase,
+                state_events: StateMap[EventBase],
+            ) -> Tuple[bool, Optional[dict]]:
+                # Assertion required because mypy can't prove we won't change
+                # `f` back to `None`. See
+                # https://mypy.readthedocs.io/en/latest/common_issues.html#narrowing-and-inner-functions
+                assert f is not None
+
+                res = await f(event, state_events)
+                if isinstance(res, dict):
+                    return True, res
+                else:
+                    return res, None
+
+            return wrap_check_event_allowed
+
+        if f.__name__ == "on_create_room":
+            # We need to wrap on_create_room because its old form would return a boolean
+            # if the room creation is denied, but now we just want it to raise an
+            # exception.
+            async def wrap_on_create_room(
+                requester: Requester, config: dict, is_requester_admin: bool
+            ) -> None:
+                # Assertion required because mypy can't prove we won't change
+                # `f` back to `None`. See
+                # https://mypy.readthedocs.io/en/latest/common_issues.html#narrowing-and-inner-functions
+                assert f is not None
+
+                res = await f(requester, config, is_requester_admin)
+                if res is False:
+                    raise SynapseError(
+                        403,
+                        "Room creation forbidden with these parameters",
+                    )
+
+            return wrap_on_create_room
+
+        def run(*args: Any, **kwargs: Any) -> Awaitable:
+            # Assertion required because mypy can't prove we won't change  `f`
+            # back to `None`. See
+            # https://mypy.readthedocs.io/en/latest/common_issues.html#narrowing-and-inner-functions
+            assert f is not None
+
+            return maybe_awaitable(f(*args, **kwargs))
+
+        return run
+
+    # Register the hooks through the module API.
+    hooks = {
+        hook: async_wrapper(getattr(third_party_rules, hook, None))
+        for hook in third_party_event_rules_methods
+    }
+
+    api.register_third_party_rules_callbacks(**hooks)
+
+
+class ThirdPartyEventRulesModuleApiCallbacks:
+    def __init__(self) -> None:
+        self.check_event_allowed_callbacks: List[CHECK_EVENT_ALLOWED_CALLBACK] = []
+        self.on_create_room_callbacks: List[ON_CREATE_ROOM_CALLBACK] = []
+        self.check_threepid_can_be_invited_callbacks: List[
+            CHECK_THREEPID_CAN_BE_INVITED_CALLBACK
+        ] = []
+        self.check_visibility_can_be_modified_callbacks: List[
+            CHECK_VISIBILITY_CAN_BE_MODIFIED_CALLBACK
+        ] = []
+        self.on_new_event_callbacks: List[ON_NEW_EVENT_CALLBACK] = []
+        self.check_can_shutdown_room_callbacks: List[
+            CHECK_CAN_SHUTDOWN_ROOM_CALLBACK
+        ] = []
+        self.check_can_deactivate_user_callbacks: List[
+            CHECK_CAN_DEACTIVATE_USER_CALLBACK
+        ] = []
+        self.on_profile_update_callbacks: List[ON_PROFILE_UPDATE_CALLBACK] = []
+        self.on_user_deactivation_status_changed_callbacks: List[
+            ON_USER_DEACTIVATION_STATUS_CHANGED_CALLBACK
+        ] = []
+        self.on_threepid_bind_callbacks: List[ON_THREEPID_BIND_CALLBACK] = []
+        self.on_add_user_third_party_identifier_callbacks: List[
+            ON_ADD_USER_THIRD_PARTY_IDENTIFIER_CALLBACK
+        ] = []
+        self.on_remove_user_third_party_identifier_callbacks: List[
+            ON_REMOVE_USER_THIRD_PARTY_IDENTIFIER_CALLBACK
+        ] = []
+
+    def register_callbacks(
+        self,
+        check_event_allowed: Optional[CHECK_EVENT_ALLOWED_CALLBACK] = None,
+        on_create_room: Optional[ON_CREATE_ROOM_CALLBACK] = None,
+        check_threepid_can_be_invited: Optional[
+            CHECK_THREEPID_CAN_BE_INVITED_CALLBACK
+        ] = None,
+        check_visibility_can_be_modified: Optional[
+            CHECK_VISIBILITY_CAN_BE_MODIFIED_CALLBACK
+        ] = None,
+        on_new_event: Optional[ON_NEW_EVENT_CALLBACK] = None,
+        check_can_shutdown_room: Optional[CHECK_CAN_SHUTDOWN_ROOM_CALLBACK] = None,
+        check_can_deactivate_user: Optional[CHECK_CAN_DEACTIVATE_USER_CALLBACK] = None,
+        on_profile_update: Optional[ON_PROFILE_UPDATE_CALLBACK] = None,
+        on_user_deactivation_status_changed: Optional[
+            ON_USER_DEACTIVATION_STATUS_CHANGED_CALLBACK
+        ] = None,
+        on_threepid_bind: Optional[ON_THREEPID_BIND_CALLBACK] = None,
+        on_add_user_third_party_identifier: Optional[
+            ON_ADD_USER_THIRD_PARTY_IDENTIFIER_CALLBACK
+        ] = None,
+        on_remove_user_third_party_identifier: Optional[
+            ON_REMOVE_USER_THIRD_PARTY_IDENTIFIER_CALLBACK
+        ] = None,
+    ) -> None:
+        """Register callbacks from modules for each hook."""
+        if check_event_allowed is not None:
+            self.check_event_allowed_callbacks.append(check_event_allowed)
+
+        if on_create_room is not None:
+            self.on_create_room_callbacks.append(on_create_room)
+
+        if check_threepid_can_be_invited is not None:
+            self.check_threepid_can_be_invited_callbacks.append(
+                check_threepid_can_be_invited,
+            )
+
+        if check_visibility_can_be_modified is not None:
+            self.check_visibility_can_be_modified_callbacks.append(
+                check_visibility_can_be_modified,
+            )
+
+        if on_new_event is not None:
+            self.on_new_event_callbacks.append(on_new_event)
+
+        if check_can_shutdown_room is not None:
+            self.check_can_shutdown_room_callbacks.append(check_can_shutdown_room)
+
+        if check_can_deactivate_user is not None:
+            self.check_can_deactivate_user_callbacks.append(check_can_deactivate_user)
+
+        if on_profile_update is not None:
+            self.on_profile_update_callbacks.append(on_profile_update)
+
+        if on_user_deactivation_status_changed is not None:
+            self.on_user_deactivation_status_changed_callbacks.append(
+                on_user_deactivation_status_changed,
+            )
+
+        if on_threepid_bind is not None:
+            self.on_threepid_bind_callbacks.append(on_threepid_bind)
+
+        if on_add_user_third_party_identifier is not None:
+            self.on_add_user_third_party_identifier_callbacks.append(
+                on_add_user_third_party_identifier
+            )
+
+        if on_remove_user_third_party_identifier is not None:
+            self.on_remove_user_third_party_identifier_callbacks.append(
+                on_remove_user_third_party_identifier
+            )
--- a/synapse/push/bulk_push_rule_evaluator.py
+++ b/synapse/push/bulk_push_rule_evaluator.py
@@ -23,7 +23,6 @@ from typing import (
    Mapping,
    Optional,
    Sequence,
-    Set,
    Tuple,
    Union,
 )
@@ -274,10 +273,7 @@ class BulkPushRuleEvaluator:
                    related_event_id, allow_none=True
                )
                if related_event is not None:
-                    related_events[relation_type] = _flatten_dict(
-                        related_event,
-                        msc3873_escape_event_match_key=self.hs.config.experimental.msc3873_escape_event_match_key,
-                    )
+                    related_events[relation_type] = _flatten_dict(related_event)

            reply_event_id = (
                event.content.get("m.relates_to", {})
@@ -292,10 +288,7 @@ class BulkPushRuleEvaluator:
                )

                if related_event is not None:
-                    related_events["m.in_reply_to"] = _flatten_dict(
-                        related_event,
-                        msc3873_escape_event_match_key=self.hs.config.experimental.msc3873_escape_event_match_key,
-                    )
+                    related_events["m.in_reply_to"] = _flatten_dict(related_event)

                    # indicate that this is from a fallback relation.
                    if relation_type == "m.thread" and event.content.get(
@@ -396,26 +389,14 @@ class BulkPushRuleEvaluator:
                        del notification_levels[key]

        # Pull out any user and room mentions.
-        mentions = event.content.get(EventContentFields.MSC3952_MENTIONS)
-        has_mentions = self._intentional_mentions_enabled and isinstance(mentions, dict)
-        user_mentions: Set[str] = set()
-        if has_mentions:
-            # mypy seems to have lost the type even though it must be a dict here.
-            assert isinstance(mentions, dict)
-            # Remove out any non-string items and convert to a set.
-            user_mentions_raw = mentions.get("user_ids")
-            if isinstance(user_mentions_raw, list):
-                user_mentions = set(
-                    filter(lambda item: isinstance(item, str), user_mentions_raw)
-                )
+        has_mentions = (
+            self._intentional_mentions_enabled
+            and EventContentFields.MSC3952_MENTIONS in event.content
+        )

        evaluator = PushRuleEvaluator(
-            _flatten_dict(
-                event,
-                msc3873_escape_event_match_key=self.hs.config.experimental.msc3873_escape_event_match_key,
-            ),
+            _flatten_dict(event),
            has_mentions,
-            user_mentions,
            room_member_count,
            sender_power_level,
            notification_levels,
@@ -423,8 +404,6 @@ class BulkPushRuleEvaluator:
            self._related_event_match_enabled,
            event.room_version.msc3931_push_features,
            self.hs.config.experimental.msc1767_enabled,  # MSC3931 flag
-            self.hs.config.experimental.msc3758_exact_event_match,
-            self.hs.config.experimental.msc3966_exact_event_property_contains,
        )

        users = rules_by_user.keys()
@@ -506,8 +485,6 @@ def _flatten_dict(
    d: Union[EventBase, Mapping[str, Any]],
    prefix: Optional[List[str]] = None,
    result: Optional[Dict[str, JsonValue]] = None,
-    *,
-    msc3873_escape_event_match_key: bool = False,
 ) -> Dict[str, JsonValue]:
    """
    Given a JSON dictionary (or event) which might contain sub dictionaries,
@@ -536,11 +513,10 @@ def _flatten_dict(
    if result is None:
        result = {}
    for key, value in d.items():
-        if msc3873_escape_event_match_key:
-            # Escape periods in the key with a backslash (and backslashes with an
-            # extra backslash). This is since a period is used as a separator between
-            # nested fields.
-            key = key.replace("\\", "\\\\").replace(".", "\\.")
+        # Escape periods in the key with a backslash (and backslashes with an
+        # extra backslash). This is since a period is used as a separator between
+        # nested fields.
+        key = key.replace("\\", "\\\\").replace(".", "\\.")

        if _is_simple_value(value):
            result[".".join(prefix + [key])] = value
@@ -548,12 +524,7 @@ def _flatten_dict(
            result[".".join(prefix + [key])] = [v for v in value if _is_simple_value(v)]
        elif isinstance(value, Mapping):
            # do not set `room_version` due to recursion considerations below
-            _flatten_dict(
-                value,
-                prefix=(prefix + [key]),
-                result=result,
-                msc3873_escape_event_match_key=msc3873_escape_event_match_key,
-            )
+            _flatten_dict(value, prefix=(prefix + [key]), result=result)

    # `room_version` should only ever be set when looking at the top level of an event
    if (
--- a/synapse/push/clientformat.py
+++ b/synapse/push/clientformat.py
@@ -41,11 +41,12 @@ def format_push_rules_for_user(

        rulearray.append(template_rule)

-        pattern_type = template_rule.pop("pattern_type", None)
-        if pattern_type == "user_id":
-            template_rule["pattern"] = user.to_string()
-        elif pattern_type == "user_localpart":
-            template_rule["pattern"] = user.localpart
+        for type_key in ("pattern", "value"):
+            type_value = template_rule.pop(f"{type_key}_type", None)
+            if type_value == "user_id":
+                template_rule[type_key] = user.to_string()
+            elif type_value == "user_localpart":
+                template_rule[type_key] = user.localpart

        template_rule["enabled"] = enabled

--- a/synapse/replication/http/membership.py
+++ b/synapse/replication/http/membership.py
@@ -142,17 +142,12 @@ class ReplicationRemoteKnockRestServlet(ReplicationEndpoint):
        }

    async def _handle_request(  # type: ignore[override]
-        self,
-        request: SynapseRequest,
-        content: JsonDict,
-        room_id: str,
-        user_id: str,
+        self, request: SynapseRequest, content: JsonDict, room_id: str, user_id: str
    ) -> Tuple[int, JsonDict]:
        remote_room_hosts = content["remote_room_hosts"]
        event_content = content["content"]

        requester = Requester.deserialize(self.store, content["requester"])
-
        request.requester = requester

        logger.debug("remote_knock: %s on room: %s", user_id, room_id)
@@ -277,16 +272,12 @@ class ReplicationRemoteRescindKnockRestServlet(ReplicationEndpoint):
        }

    async def _handle_request(  # type: ignore[override]
-        self,
-        request: SynapseRequest,
-        content: JsonDict,
-        knock_event_id: str,
+        self, request: SynapseRequest, content: JsonDict, knock_event_id: str
    ) -> Tuple[int, JsonDict]:
        txn_id = content["txn_id"]
        event_content = content["content"]

        requester = Requester.deserialize(self.store, content["requester"])
-
        request.requester = requester

        # hopefully we're now on the master, so this won't recurse!
@@ -363,3 +354,5 @@ def register_servlets(hs: "HomeServer", http_server: HttpServer) -> None:
    ReplicationRemoteJoinRestServlet(hs).register(http_server)
    ReplicationRemoteRejectInviteRestServlet(hs).register(http_server)
    ReplicationUserJoinedLeftRoomRestServlet(hs).register(http_server)
+    ReplicationRemoteKnockRestServlet(hs).register(http_server)
+    ReplicationRemoteRescindKnockRestServlet(hs).register(http_server)
--- a/synapse/rest/init.py
+++ b/synapse/rest/init.py
@@ -139,7 +139,7 @@ class ClientRestResource(JsonResource):
        relations.register_servlets(hs, client_resource)
        if is_main_process:
            password_policy.register_servlets(hs, client_resource)
-            knock.register_servlets(hs, client_resource)
+        knock.register_servlets(hs, client_resource)

        # moving to /_synapse/admin
        if is_main_process:
--- a/synapse/rest/admin/server_notice_servlet.py
+++ b/synapse/rest/admin/server_notice_servlet.py
@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 from http import HTTPStatus
-from typing import TYPE_CHECKING, Awaitable, Optional, Tuple
+from typing import TYPE_CHECKING, Optional, Tuple

 from synapse.api.constants import EventTypes
 from synapse.api.errors import NotFoundError, SynapseError
@@ -23,10 +23,10 @@ from synapse.http.servlet import (
    parse_json_object_from_request,
 )
 from synapse.http.site import SynapseRequest
-from synapse.rest.admin import assert_requester_is_admin
-from synapse.rest.admin._base import admin_patterns
+from synapse.logging.opentracing import set_tag
+from synapse.rest.admin._base import admin_patterns, assert_user_is_admin
 from synapse.rest.client.transactions import HttpTransactionCache
-from synapse.types import JsonDict, UserID
+from synapse.types import JsonDict, Requester, UserID

 if TYPE_CHECKING:
    from synapse.server import HomeServer
@@ -70,10 +70,13 @@ class SendServerNoticeServlet(RestServlet):
            self.__class__.__name__,
        )

-    async def on_POST(
-        self, request: SynapseRequest, txn_id: Optional[str] = None
+    async def _do(
+        self,
+        request: SynapseRequest,
+        requester: Requester,
+        txn_id: Optional[str],
    ) -> Tuple[int, JsonDict]:
-        await assert_requester_is_admin(self.auth, request)
+        await assert_user_is_admin(self.auth, requester)
        body = parse_json_object_from_request(request)
        assert_params_in_dict(body, ("user_id", "content"))
        event_type = body.get("type", EventTypes.Message)
@@ -106,9 +109,18 @@ class SendServerNoticeServlet(RestServlet):

        return HTTPStatus.OK, {"event_id": event.event_id}

-    def on_PUT(
+    async def on_POST(
+        self,
+        request: SynapseRequest,
+    ) -> Tuple[int, JsonDict]:
+        requester = await self.auth.get_user_by_req(request)
+        return await self._do(request, requester, None)
+
+    async def on_PUT(
        self, request: SynapseRequest, txn_id: str
-    ) -> Awaitable[Tuple[int, JsonDict]]:
-        return self.txns.fetch_or_execute_request(
-            request, self.on_POST, request, txn_id
+    ) -> Tuple[int, JsonDict]:
+        requester = await self.auth.get_user_by_req(request)
+        set_tag("txn_id", txn_id)
+        return await self.txns.fetch_or_execute_request(
+            request, requester, self._do, request, requester, txn_id
        )
--- a/synapse/rest/admin/users.py
+++ b/synapse/rest/admin/users.py
@@ -683,19 +683,18 @@ class AccountValidityRenewServlet(RestServlet):
    PATTERNS = admin_patterns("/account_validity/validity$")

    def __init__(self, hs: "HomeServer"):
-        self.account_activity_handler = hs.get_account_validity_handler()
+        self.account_validity_handler = hs.get_account_validity_handler()
+        self.account_validity_module_callbacks = (
+            hs.get_module_api_callbacks().account_validity
+        )
        self.auth = hs.get_auth()

    async def on_POST(self, request: SynapseRequest) -> Tuple[int, JsonDict]:
        await assert_requester_is_admin(self.auth, request)

-        if self.account_activity_handler.on_legacy_admin_request_callback:
-            expiration_ts = (
-                await (
-                    self.account_activity_handler.on_legacy_admin_request_callback(
-                        request
-                    )
-                )
+        if self.account_validity_module_callbacks.on_legacy_admin_request_callback:
+            expiration_ts = await self.account_validity_module_callbacks.on_legacy_admin_request_callback(
+                request
            )
        else:
            body = parse_json_object_from_request(request)
@@ -706,7 +705,7 @@ class AccountValidityRenewServlet(RestServlet):
                    "Missing property 'user_id' in the request body",
                )

-            expiration_ts = await self.account_activity_handler.renew_account_for_user(
+            expiration_ts = await self.account_validity_handler.renew_account_for_user(
                body["user_id"],
                body.get("expiration_ts"),
                not body.get("enable_renewal_emails", True),
--- a/synapse/rest/client/devices.py
+++ b/synapse/rest/client/devices.py
@@ -255,7 +255,7 @@ class DehydratedDeviceServlet(RestServlet):

    """

-    PATTERNS = client_patterns("/org.matrix.msc2697.v2/dehydrated_device", releases=())
+    PATTERNS = client_patterns("/org.matrix.msc2697.v2/dehydrated_device$", releases=())

    def __init__(self, hs: "HomeServer"):
        super().__init__()
--- a/synapse/rest/client/events.py
+++ b/synapse/rest/client/events.py
@@ -17,6 +17,7 @@ import logging
 from typing import TYPE_CHECKING, Dict, List, Tuple, Union

 from synapse.api.errors import SynapseError
+from synapse.events.utils import SerializeEventConfig
 from synapse.http.server import HttpServer
 from synapse.http.servlet import RestServlet, parse_string
 from synapse.http.site import SynapseRequest
@@ -43,9 +44,8 @@ class EventStreamRestServlet(RestServlet):

    async def on_GET(self, request: SynapseRequest) -> Tuple[int, JsonDict]:
        requester = await self.auth.get_user_by_req(request, allow_guest=True)
-        is_guest = requester.is_guest
        args: Dict[bytes, List[bytes]] = request.args  # type: ignore
-        if is_guest:
+        if requester.is_guest:
            if b"room_id" not in args:
                raise SynapseError(400, "Guest users must specify room_id param")
        room_id = parse_string(request, "room_id")
@@ -63,13 +63,12 @@ class EventStreamRestServlet(RestServlet):
        as_client_event = b"raw" not in args

        chunk = await self.event_stream_handler.get_stream(
-            requester.user.to_string(),
+            requester,
            pagin_config,
            timeout=timeout,
            as_client_event=as_client_event,
-            affect_presence=(not is_guest),
+            affect_presence=(not requester.is_guest),
            room_id=room_id,
-            is_guest=is_guest,
        )

        return 200, chunk
@@ -91,9 +90,12 @@ class EventRestServlet(RestServlet):
        requester = await self.auth.get_user_by_req(request)
        event = await self.event_handler.get_event(requester.user, None, event_id)

-        time_now = self.clock.time_msec()
        if event:
-            result = self._event_serializer.serialize_event(event, time_now)
+            result = self._event_serializer.serialize_event(
+                event,
+                self.clock.time_msec(),
+                config=SerializeEventConfig(requester=requester),
+            )
            return 200, result
        else:
            return 404, "Event not found."
--- a/synapse/rest/client/keys.py
+++ b/synapse/rest/client/keys.py
@@ -312,15 +312,29 @@ class SigningKeyUploadServlet(RestServlet):
        user_id = requester.user.to_string()
        body = parse_json_object_from_request(request)

-        await self.auth_handler.validate_user_via_ui_auth(
-            requester,
-            request,
-            body,
-            "add a device signing key to your account",
-            # Allow skipping of UI auth since this is frequently called directly
-            # after login and it is silly to ask users to re-auth immediately.
-            can_skip_ui_auth=True,
-        )
+        if self.hs.config.experimental.msc3967_enabled:
+            if await self.e2e_keys_handler.is_cross_signing_set_up_for_user(user_id):
+                # If we already have a master key then cross signing is set up and we require UIA to reset
+                await self.auth_handler.validate_user_via_ui_auth(
+                    requester,
+                    request,
+                    body,
+                    "reset the device signing key on your account",
+                    # Do not allow skipping of UIA auth.
+                    can_skip_ui_auth=False,
+                )
+            # Otherwise we don't require UIA since we are setting up cross signing for first time
+        else:
+            # Previous behaviour is to always require UIA but allow it to be skipped
+            await self.auth_handler.validate_user_via_ui_auth(
+                requester,
+                request,
+                body,
+                "add a device signing key to your account",
+                # Allow skipping of UI auth since this is frequently called directly
+                # after login and it is silly to ask users to re-auth immediately.
+                can_skip_ui_auth=True,
+            )

        result = await self.e2e_keys_handler.upload_signing_keys_for_user(user_id, body)
        return 200, result
--- a/synapse/rest/client/knock.py
+++ b/synapse/rest/client/knock.py
@@ -13,7 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 import logging
-from typing import TYPE_CHECKING, Awaitable, Dict, List, Optional, Tuple
+from typing import TYPE_CHECKING, Dict, List, Tuple

 from synapse.api.constants import Membership
 from synapse.api.errors import SynapseError
@@ -24,8 +24,6 @@ from synapse.http.servlet import (
    parse_strings_from_args,
 )
 from synapse.http.site import SynapseRequest
-from synapse.logging.opentracing import set_tag
-from synapse.rest.client.transactions import HttpTransactionCache
 from synapse.types import JsonDict, RoomAlias, RoomID

 if TYPE_CHECKING:
@@ -45,7 +43,6 @@ class KnockRoomAliasServlet(RestServlet):

    def __init__(self, hs: "HomeServer"):
        super().__init__()
-        self.txns = HttpTransactionCache(hs)
        self.room_member_handler = hs.get_room_member_handler()
        self.auth = hs.get_auth()

@@ -53,7 +50,6 @@ class KnockRoomAliasServlet(RestServlet):
        self,
        request: SynapseRequest,
        room_identifier: str,
-        txn_id: Optional[str] = None,
    ) -> Tuple[int, JsonDict]:
        requester = await self.auth.get_user_by_req(request)

@@ -67,7 +63,6 @@ class KnockRoomAliasServlet(RestServlet):

            # twisted.web.server.Request.args is incorrectly defined as Optional[Any]
            args: Dict[bytes, List[bytes]] = request.args  # type: ignore
-
            remote_room_hosts = parse_strings_from_args(
                args, "server_name", required=False
            )
@@ -86,7 +81,6 @@ class KnockRoomAliasServlet(RestServlet):
            target=requester.user,
            room_id=room_id,
            action=Membership.KNOCK,
-            txn_id=txn_id,
            third_party_signed=None,
            remote_room_hosts=remote_room_hosts,
            content=event_content,
@@ -94,15 +88,6 @@ class KnockRoomAliasServlet(RestServlet):

        return 200, {"room_id": room_id}

-    def on_PUT(
-        self, request: SynapseRequest, room_identifier: str, txn_id: str
-    ) -> Awaitable[Tuple[int, JsonDict]]:
-        set_tag("txn_id", txn_id)
-
-        return self.txns.fetch_or_execute_request(
-            request, self.on_POST, request, room_identifier, txn_id
-        )
-

 def register_servlets(hs: "HomeServer", http_server: HttpServer) -> None:
    KnockRoomAliasServlet(hs).register(http_server)
--- a/synapse/rest/client/notifications.py
+++ b/synapse/rest/client/notifications.py
@@ -72,6 +72,12 @@ class NotificationsServlet(RestServlet):

        next_token = None

+        serialize_options = SerializeEventConfig(
+            event_format=format_event_for_client_v2_without_room_id,
+            requester=requester,
+        )
+        now = self.clock.time_msec()
+
        for pa in push_actions:
            returned_pa = {
                "room_id": pa.room_id,
@@ -81,10 +87,8 @@ class NotificationsServlet(RestServlet):
                "event": (
                    self._event_serializer.serialize_event(
                        notif_events[pa.event_id],
-                        self.clock.time_msec(),
-                        config=SerializeEventConfig(
-                            event_format=format_event_for_client_v2_without_room_id
-                        ),
+                        now,
+                        config=serialize_options,
                    )
                ),
            }
--- a/synapse/rest/client/room.py
+++ b/synapse/rest/client/room.py
@@ -37,7 +37,7 @@ from synapse.api.errors import (
    UnredactedContentDeletedError,
 )
 from synapse.api.filtering import Filter
-from synapse.events.utils import format_event_for_client_v2
+from synapse.events.utils import SerializeEventConfig, format_event_for_client_v2
 from synapse.http.server import HttpServer
 from synapse.http.servlet import (
    ResolveRoomIdMixin,
@@ -57,7 +57,7 @@ from synapse.metrics.background_process_metrics import run_as_background_process
 from synapse.rest.client._base import client_patterns
 from synapse.rest.client.transactions import HttpTransactionCache
 from synapse.streams.config import PaginationConfig
-from synapse.types import JsonDict, StreamToken, ThirdPartyInstanceID, UserID
+from synapse.types import JsonDict, Requester, StreamToken, ThirdPartyInstanceID, UserID
 from synapse.types.state import StateFilter
 from synapse.util import json_decoder
 from synapse.util.cancellation import cancellable
@@ -151,15 +151,22 @@ class RoomCreateRestServlet(TransactionRestServlet):
        PATTERNS = "/createRoom"
        register_txn_path(self, PATTERNS, http_server)

-    def on_PUT(
+    async def on_PUT(
        self, request: SynapseRequest, txn_id: str
-    ) -> Awaitable[Tuple[int, JsonDict]]:
+    ) -> Tuple[int, JsonDict]:
+        requester = await self.auth.get_user_by_req(request)
        set_tag("txn_id", txn_id)
-        return self.txns.fetch_or_execute_request(request, self.on_POST, request)
+        return await self.txns.fetch_or_execute_request(
+            request, requester, self._do, request, requester
+        )

    async def on_POST(self, request: SynapseRequest) -> Tuple[int, JsonDict]:
        requester = await self.auth.get_user_by_req(request)
+        return await self._do(request, requester)

+    async def _do(
+        self, request: SynapseRequest, requester: Requester
+    ) -> Tuple[int, JsonDict]:
        room_id, _, _ = await self._room_creation_handler.create_room(
            requester, self.get_room_config(request)
        )
@@ -172,9 +179,9 @@ class RoomCreateRestServlet(TransactionRestServlet):


 # TODO: Needs unit testing for generic events
-class RoomStateEventRestServlet(TransactionRestServlet):
+class RoomStateEventRestServlet(RestServlet):
    def __init__(self, hs: "HomeServer"):
-        super().__init__(hs)
+        super().__init__()
        self.event_creation_handler = hs.get_event_creation_handler()
        self.room_member_handler = hs.get_room_member_handler()
        self.message_handler = hs.get_message_handler()
@@ -324,16 +331,16 @@ class RoomSendEventRestServlet(TransactionRestServlet):
    def register(self, http_server: HttpServer) -> None:
        # /rooms/$roomid/send/$event_type[/$txn_id]
        PATTERNS = "/rooms/(?P<room_id>[^/]*)/send/(?P<event_type>[^/]*)"
-        register_txn_path(self, PATTERNS, http_server, with_get=True)
+        register_txn_path(self, PATTERNS, http_server)

-    async def on_POST(
+    async def _do(
        self,
        request: SynapseRequest,
+        requester: Requester,
        room_id: str,
        event_type: str,
-        txn_id: Optional[str] = None,
+        txn_id: Optional[str],
    ) -> Tuple[int, JsonDict]:
-        requester = await self.auth.get_user_by_req(request, allow_guest=True)
        content = parse_json_object_from_request(request)

        event_dict: JsonDict = {
@@ -362,18 +369,30 @@ class RoomSendEventRestServlet(TransactionRestServlet):
        set_tag("event_id", event_id)
        return 200, {"event_id": event_id}

-    def on_GET(
-        self, request: SynapseRequest, room_id: str, event_type: str, txn_id: str
-    ) -> Tuple[int, str]:
-        return 200, "Not implemented"
+    async def on_POST(
+        self,
+        request: SynapseRequest,
+        room_id: str,
+        event_type: str,
+    ) -> Tuple[int, JsonDict]:
+        requester = await self.auth.get_user_by_req(request, allow_guest=True)
+        return await self._do(request, requester, room_id, event_type, None)

-    def on_PUT(
+    async def on_PUT(
        self, request: SynapseRequest, room_id: str, event_type: str, txn_id: str
-    ) -> Awaitable[Tuple[int, JsonDict]]:
+    ) -> Tuple[int, JsonDict]:
+        requester = await self.auth.get_user_by_req(request, allow_guest=True)
        set_tag("txn_id", txn_id)

-        return self.txns.fetch_or_execute_request(
-            request, self.on_POST, request, room_id, event_type, txn_id
+        return await self.txns.fetch_or_execute_request(
+            request,
+            requester,
+            self._do,
+            request,
+            requester,
+            room_id,
+            event_type,
+            txn_id,
        )


@@ -389,14 +408,13 @@ class JoinRoomAliasServlet(ResolveRoomIdMixin, TransactionRestServlet):
        PATTERNS = "/join/(?P<room_identifier>[^/]*)"
        register_txn_path(self, PATTERNS, http_server)

-    async def on_POST(
+    async def _do(
        self,
        request: SynapseRequest,
+        requester: Requester,
        room_identifier: str,
-        txn_id: Optional[str] = None,
+        txn_id: Optional[str],
    ) -> Tuple[int, JsonDict]:
-        requester = await self.auth.get_user_by_req(request, allow_guest=True)
-
        content = parse_json_object_from_request(request, allow_empty_body=True)

        # twisted.web.server.Request.args is incorrectly defined as Optional[Any]
@@ -420,22 +438,31 @@ class JoinRoomAliasServlet(ResolveRoomIdMixin, TransactionRestServlet):

        return 200, {"room_id": room_id}

-    def on_PUT(
+    async def on_POST(
+        self,
+        request: SynapseRequest,
+        room_identifier: str,
+    ) -> Tuple[int, JsonDict]:
+        requester = await self.auth.get_user_by_req(request, allow_guest=True)
+        return await self._do(request, requester, room_identifier, None)
+
+    async def on_PUT(
        self, request: SynapseRequest, room_identifier: str, txn_id: str
-    ) -> Awaitable[Tuple[int, JsonDict]]:
+    ) -> Tuple[int, JsonDict]:
+        requester = await self.auth.get_user_by_req(request, allow_guest=True)
        set_tag("txn_id", txn_id)

-        return self.txns.fetch_or_execute_request(
-            request, self.on_POST, request, room_identifier, txn_id
+        return await self.txns.fetch_or_execute_request(
+            request, requester, self._do, request, requester, room_identifier, txn_id
        )


 # TODO: Needs unit testing
-class PublicRoomListRestServlet(TransactionRestServlet):
+class PublicRoomListRestServlet(RestServlet):
    PATTERNS = client_patterns("/publicRooms$", v1=True)

    def __init__(self, hs: "HomeServer"):
-        super().__init__(hs)
+        super().__init__()
        self.hs = hs
        self.auth = hs.get_auth()

@@ -814,11 +841,13 @@ class RoomEventServlet(RestServlet):
                [event], requester.user.to_string()
            )

-            time_now = self.clock.time_msec()
            # per MSC2676, /rooms/{roomId}/event/{eventId}, should return the
            # *original* event, rather than the edited version
            event_dict = self._event_serializer.serialize_event(
-                event, time_now, bundle_aggregations=aggregations, apply_edits=False
+                event,
+                self.clock.time_msec(),
+                bundle_aggregations=aggregations,
+                config=SerializeEventConfig(requester=requester),
            )
            return 200, event_dict

@@ -863,24 +892,30 @@ class RoomEventContextServlet(RestServlet):
            raise SynapseError(404, "Event not found.", errcode=Codes.NOT_FOUND)

        time_now = self.clock.time_msec()
+        serializer_options = SerializeEventConfig(requester=requester)
        results = {
            "events_before": self._event_serializer.serialize_events(
                event_context.events_before,
                time_now,
                bundle_aggregations=event_context.aggregations,
+                config=serializer_options,
            ),
            "event": self._event_serializer.serialize_event(
                event_context.event,
                time_now,
                bundle_aggregations=event_context.aggregations,
+                config=serializer_options,
            ),
            "events_after": self._event_serializer.serialize_events(
                event_context.events_after,
                time_now,
                bundle_aggregations=event_context.aggregations,
+                config=serializer_options,
            ),
            "state": self._event_serializer.serialize_events(
-                event_context.state, time_now
+                event_context.state,
+                time_now,
+                config=serializer_options,
            ),
            "start": event_context.start,
            "end": event_context.end,
@@ -899,22 +934,25 @@ class RoomForgetRestServlet(TransactionRestServlet):
        PATTERNS = "/rooms/(?P<room_id>[^/]*)/forget"
        register_txn_path(self, PATTERNS, http_server)

-    async def on_POST(
-        self, request: SynapseRequest, room_id: str, txn_id: Optional[str] = None
-    ) -> Tuple[int, JsonDict]:
-        requester = await self.auth.get_user_by_req(request, allow_guest=False)
-
+    async def _do(self, requester: Requester, room_id: str) -> Tuple[int, JsonDict]:
        await self.room_member_handler.forget(user=requester.user, room_id=room_id)

        return 200, {}

-    def on_PUT(
+    async def on_POST(
+        self, request: SynapseRequest, room_id: str
+    ) -> Tuple[int, JsonDict]:
+        requester = await self.auth.get_user_by_req(request, allow_guest=False)
+        return await self._do(requester, room_id)
+
+    async def on_PUT(
        self, request: SynapseRequest, room_id: str, txn_id: str
-    ) -> Awaitable[Tuple[int, JsonDict]]:
+    ) -> Tuple[int, JsonDict]:
+        requester = await self.auth.get_user_by_req(request, allow_guest=False)
        set_tag("txn_id", txn_id)

-        return self.txns.fetch_or_execute_request(
-            request, self.on_POST, request, room_id, txn_id
+        return await self.txns.fetch_or_execute_request(
+            request, requester, self._do, requester, room_id
        )


@@ -926,22 +964,21 @@ class RoomMembershipRestServlet(TransactionRestServlet):
        self.auth = hs.get_auth()

    def register(self, http_server: HttpServer) -> None:
-        # /rooms/$roomid/[invite|join|leave]
+        # /rooms/$roomid/[join|invite|leave|ban|unban|kick]
        PATTERNS = (
            "/rooms/(?P<room_id>[^/]*)/"
            "(?P<membership_action>join|invite|leave|ban|unban|kick)"
        )
        register_txn_path(self, PATTERNS, http_server)

-    async def on_POST(
+    async def _do(
        self,
        request: SynapseRequest,
+        requester: Requester,
        room_id: str,
        membership_action: str,
-        txn_id: Optional[str] = None,
+        txn_id: Optional[str],
    ) -> Tuple[int, JsonDict]:
-        requester = await self.auth.get_user_by_req(request, allow_guest=True)
-
        if requester.is_guest and membership_action not in {
            Membership.JOIN,
            Membership.LEAVE,
@@ -1006,13 +1043,30 @@ class RoomMembershipRestServlet(TransactionRestServlet):

        return 200, return_value

-    def on_PUT(
+    async def on_POST(
+        self,
+        request: SynapseRequest,
+        room_id: str,
+        membership_action: str,
+    ) -> Tuple[int, JsonDict]:
+        requester = await self.auth.get_user_by_req(request, allow_guest=True)
+        return await self._do(request, requester, room_id, membership_action, None)
+
+    async def on_PUT(
        self, request: SynapseRequest, room_id: str, membership_action: str, txn_id: str
-    ) -> Awaitable[Tuple[int, JsonDict]]:
+    ) -> Tuple[int, JsonDict]:
+        requester = await self.auth.get_user_by_req(request, allow_guest=True)
        set_tag("txn_id", txn_id)

-        return self.txns.fetch_or_execute_request(
-            request, self.on_POST, request, room_id, membership_action, txn_id
+        return await self.txns.fetch_or_execute_request(
+            request,
+            requester,
+            self._do,
+            request,
+            requester,
+            room_id,
+            membership_action,
+            txn_id,
        )


@@ -1028,14 +1082,14 @@ class RoomRedactEventRestServlet(TransactionRestServlet):
        PATTERNS = "/rooms/(?P<room_id>[^/]*)/redact/(?P<event_id>[^/]*)"
        register_txn_path(self, PATTERNS, http_server)

-    async def on_POST(
+    async def _do(
        self,
        request: SynapseRequest,
+        requester: Requester,
        room_id: str,
        event_id: str,
-        txn_id: Optional[str] = None,
+        txn_id: Optional[str],
    ) -> Tuple[int, JsonDict]:
-        requester = await self.auth.get_user_by_req(request)
        content = parse_json_object_from_request(request)

        try:
@@ -1086,13 +1140,23 @@ class RoomRedactEventRestServlet(TransactionRestServlet):
        set_tag("event_id", event_id)
        return 200, {"event_id": event_id}

-    def on_PUT(
+    async def on_POST(
+        self,
+        request: SynapseRequest,
+        room_id: str,
+        event_id: str,
+    ) -> Tuple[int, JsonDict]:
+        requester = await self.auth.get_user_by_req(request)
+        return await self._do(request, requester, room_id, event_id, None)
+
+    async def on_PUT(
        self, request: SynapseRequest, room_id: str, event_id: str, txn_id: str
-    ) -> Awaitable[Tuple[int, JsonDict]]:
+    ) -> Tuple[int, JsonDict]:
+        requester = await self.auth.get_user_by_req(request)
        set_tag("txn_id", txn_id)

-        return self.txns.fetch_or_execute_request(
-            request, self.on_POST, request, room_id, event_id, txn_id
+        return await self.txns.fetch_or_execute_request(
+            request, requester, self._do, request, requester, room_id, event_id, txn_id
        )


@@ -1192,7 +1256,7 @@ class SearchRestServlet(RestServlet):
        content = parse_json_object_from_request(request)

        batch = parse_string(request, "next_batch")
-        results = await self.search_handler.search(requester.user, content, batch)
+        results = await self.search_handler.search(requester, content, batch)

        return 200, results

@@ -1216,7 +1280,6 @@ def register_txn_path(
    servlet: RestServlet,
    regex_string: str,
    http_server: HttpServer,
-    with_get: bool = False,
 ) -> None:
    """Registers a transaction-based path.

@@ -1228,7 +1291,6 @@ def register_txn_path(
        regex_string: The regex string to register. Must NOT have a
            trailing $ as this string will be appended to.
        http_server: The http_server to register paths with.
-        with_get: True to also register respective GET paths for the PUTs.
    """
    on_POST = getattr(servlet, "on_POST", None)
    on_PUT = getattr(servlet, "on_PUT", None)
@@ -1246,18 +1308,6 @@ def register_txn_path(
        on_PUT,
        servlet.__class__.__name__,
    )
-    on_GET = getattr(servlet, "on_GET", None)
-    if with_get:
-        if on_GET is None:
-            raise RuntimeError(
-                "register_txn_path called with with_get = True, but no on_GET method exists"
-            )
-        http_server.register_paths(
-            "GET",
-            client_patterns(regex_string + "/(?P<txn_id>[^/]*)$", v1=True),
-            on_GET,
-            servlet.__class__.__name__,
-        )


 class TimestampLookupRestServlet(RestServlet):
--- a/synapse/rest/client/room_batch.py
+++ b/synapse/rest/client/room_batch.py
@@ -15,9 +15,7 @@
 import logging
 import re
 from http import HTTPStatus
-from typing import TYPE_CHECKING, Awaitable, Tuple
-
-from twisted.web.server import Request
+from typing import TYPE_CHECKING, Tuple

 from synapse.api.constants import EventContentFields
 from synapse.api.errors import AuthError, Codes, SynapseError
@@ -30,7 +28,6 @@ from synapse.http.servlet import (
    parse_strings_from_args,
 )
 from synapse.http.site import SynapseRequest
-from synapse.rest.client.transactions import HttpTransactionCache
 from synapse.types import JsonDict

 if TYPE_CHECKING:
@@ -79,7 +76,6 @@ class RoomBatchSendEventRestServlet(RestServlet):
        self.event_creation_handler = hs.get_event_creation_handler()
        self.auth = hs.get_auth()
        self.room_batch_handler = hs.get_room_batch_handler()
-        self.txns = HttpTransactionCache(hs)

    async def on_POST(
        self, request: SynapseRequest, room_id: str
@@ -249,16 +245,6 @@ class RoomBatchSendEventRestServlet(RestServlet):

        return HTTPStatus.OK, response_dict

-    def on_GET(self, request: Request, room_id: str) -> Tuple[int, str]:
-        return HTTPStatus.NOT_IMPLEMENTED, "Not implemented"
-
-    def on_PUT(
-        self, request: SynapseRequest, room_id: str
-    ) -> Awaitable[Tuple[int, JsonDict]]:
-        return self.txns.fetch_or_execute_request(
-            request, self.on_POST, request, room_id
-        )
-

 def register_servlets(hs: "HomeServer", http_server: HttpServer) -> None:
    msc2716_enabled = hs.config.experimental.msc2716_enabled
--- a/synapse/rest/client/sendtodevice.py
+++ b/synapse/rest/client/sendtodevice.py
@@ -13,7 +13,7 @@
 # limitations under the License.

 import logging
-from typing import TYPE_CHECKING, Awaitable, Tuple
+from typing import TYPE_CHECKING, Tuple

 from synapse.http import servlet
 from synapse.http.server import HttpServer
@@ -21,7 +21,7 @@ from synapse.http.servlet import assert_params_in_dict, parse_json_object_from_r
 from synapse.http.site import SynapseRequest
 from synapse.logging.opentracing import set_tag
 from synapse.rest.client.transactions import HttpTransactionCache
-from synapse.types import JsonDict
+from synapse.types import JsonDict, Requester

 from ._base import client_patterns

@@ -43,19 +43,26 @@ class SendToDeviceRestServlet(servlet.RestServlet):
        self.txns = HttpTransactionCache(hs)
        self.device_message_handler = hs.get_device_message_handler()

-    def on_PUT(
-        self, request: SynapseRequest, message_type: str, txn_id: str
-    ) -> Awaitable[Tuple[int, JsonDict]]:
-        set_tag("txn_id", txn_id)
-        return self.txns.fetch_or_execute_request(
-            request, self._put, request, message_type, txn_id
-        )
-
-    async def _put(
+    async def on_PUT(
        self, request: SynapseRequest, message_type: str, txn_id: str
    ) -> Tuple[int, JsonDict]:
        requester = await self.auth.get_user_by_req(request, allow_guest=True)
+        set_tag("txn_id", txn_id)
+        return await self.txns.fetch_or_execute_request(
+            request,
+            requester,
+            self._put,
+            request,
+            requester,
+            message_type,
+        )

+    async def _put(
+        self,
+        request: SynapseRequest,
+        requester: Requester,
+        message_type: str,
+    ) -> Tuple[int, JsonDict]:
        content = parse_json_object_from_request(request)
        assert_params_in_dict(content, ("messages",))

--- a/Show More
+++ b/Show More
Author	SHA1	Message	Date
Andrew Morgan	3dcc1efc43	Move callback-related code from AccountData to its own class	2023-03-09 16:50:31 +00:00
Andrew Morgan	46c0ab559b	Move callback-related code from the PasswordAuthProvider to its own class	2023-03-09 16:50:31 +00:00
Andrew Morgan	e8cdfc771b	Move callback-related code from the BackgroundUpdater to its own class	2023-03-09 16:50:31 +00:00
Andrew Morgan	1b30b82ac6	Move callback-related code from the PresenceRouter to its own class	2023-03-09 16:50:31 +00:00
Andrew Morgan	266f426c50	Move callback-related code from ThirdPartyEventRules to its own class And update the many references.	2023-03-09 16:50:31 +00:00
Andrew Morgan	c3c3c6d200	Move callback-related code from the SpamChecker to its own class And update the many references.	2023-03-09 16:50:31 +00:00
Andrew Morgan	9cd8fecdc5	Move Account Validity callbacks to a dedicated file Spreading module callback registration across the codebase is both a bit messy and makes it unclear where a user should register callbacks if they want to define a new class of callbacks. Consolidating these under the synapse.module_api module cleans things up a bit, puts related code in the same place and makes it much more obvious how to extend it.	2023-03-09 16:50:31 +00:00
Patrick Cloke	f4fc83ac75	Add a missing endpoint to the workers documentation. (#15223 )	2023-03-08 07:51:34 -05:00
Shay	a368d30c1c	More speedups/fixes to creating batched events (#15195 )	2023-03-07 13:54:39 -08:00
Patrick Cloke	20ed8c926b	Stabilize support for MSC3873: disambuguated event push keys. (#15190 ) This removes the experimental configuration option and always escapes the push rule condition keys. Also escapes any (experimental) push rule condition keys in the base rules which contain dot in a field name.	2023-03-07 11:27:57 -05:00
Quentin Gliech	47bc84dd53	Pass the Requester down to the HttpTransactionCache. (#15200 )	2023-03-07 16:05:22 +00:00
Patrick Cloke	820f02b70b	Stabilize support for MSC3966: event_property_contains push condition. (#15187 ) This removes the configuration flag & updates the identifiers to use the stable version.	2023-03-07 10:06:02 -05:00
David Robertson	2af1a982c1	Remove duplicate entry from changelog	2023-03-07 13:34:06 +00:00
David Robertson	8314646cd3	Update changelog	2023-03-07 13:30:47 +00:00
David Robertson	506e24ffc4	1.79.0rc1	2023-03-07 12:11:15 +00:00
David Robertson	c0854ce65a	Hack to rebuild the complement editable image (#15184 ) * Hack to rebuild the complement editable image * Changelog	2023-03-07 11:51:18 +00:00
dependabot[bot]	869ef75cb7	Bump types-pyopenssl from 22.1.0.2 to 23.0.0.4 (#15213 )	2023-03-07 10:14:21 +00:00
dependabot[bot]	2a869d257f	Bump types-pillow from 9.4.0.13 to 9.4.0.17 (#15211 )	2023-03-07 10:14:05 +00:00
dependabot[bot]	a9478e436e	Bump types-setuptools from 67.4.0.3 to 67.5.0.0 (#15212 )	2023-03-07 10:13:51 +00:00
dependabot[bot]	89ae8ce7ca	Bump types-psycopg2 from 2.9.21.4 to 2.9.21.8 (#15210 )	2023-03-07 10:13:24 +00:00
dependabot[bot]	c114befd6b	Bump types-commonmark from 0.9.2.1 to 0.9.2.2 (#15209 )	2023-03-07 10:13:10 +00:00
Erik Johnston	c69aae94cd	Split up txn for fetching device keys (#15215 ) We look up keys in batches, but we should do that outside of the transaction to avoid starving the database pool.	2023-03-07 08:51:34 +00:00
Quentin Gliech	41f127e068	Pass the requester during event serialization. (#15174 ) This allows Synapse to properly include the transaction ID in the unsigned data of events.	2023-03-06 16:08:39 +00:00
Patrick Cloke	05e0a4089a	Stop applying edits to event contents (MSC3925). (#15193 ) Enables MSC3925 support by default, which: * Includes the full edit event in the bundled aggregations of an edited event. * Stops modifying the original event's content to return the new content from the edit event. This is a backwards-incompatible change that is considered to be "correct" by the spec.	2023-03-06 09:43:01 -05:00
Patrick Cloke	fd9cadcf53	Stabilize support for MSC3758: event_property_is push condition (#15185 ) This removes the configuration flag & updates the identifiers to use the stable version.	2023-03-06 08:38:01 -05:00
dependabot[bot]	95876cf5f1	Bump serde_json from 1.0.93 to 1.0.94 (#15214 )Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com> Co-authored-by: GitHub Actions <github-actions[bot]@users.noreply.github.com> * Bump serde_json from 1.0.93 to 1.0.94 Bumps [serde_json](https://github.com/serde-rs/json) from 1.0.93 to 1.0.94. - [Release notes](https://github.com/serde-rs/json/releases) - [Commits](https://github.com/serde-rs/json/compare/v1.0.93...v1.0.94) --- updated-dependencies: - dependency-name: serde_json dependency-type: direct:production update-type: version-update:semver-patch ... Signed-off-by: dependabot[bot] <support@github.com> * Changelog --------- Signed-off-by: dependabot[bot] <support@github.com> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com> Co-authored-by: GitHub Actions <github-actions[bot]@users.noreply.github.com>	2023-03-06 12:01:05 +00:00
Erik Johnston	242d2a27ce	Use nightly rustfmt in CI (#15188 ) As we use some nightly only options, e.g. to group and sort imports consistently.	2023-03-03 14:26:14 +00:00
6543	6b6e91e610	Fix ICU tests on alpine / macOS. (#15177 ) The word boundary behaviour is slightly different, consider it acceptable for the tests.	2023-03-03 14:22:06 +00:00
Patrick Cloke	02f74f3a99	Combine AbstractStreamIdTracker and AbstractStreamIdGenerator. (#15192 ) AbstractStreamIdTracker (now) has only a single sub-class: AbstractStreamIdGenerator, combine them to simplify some code and remove any direct references to AbstractStreamIdTracker.	2023-03-03 08:13:37 -05:00
Quentin Gliech	848f7e3d5f	Remove unspecced and buggy `PUT` method on the unstable `/rooms/<room_id>/batch_send` endpoint. (#15199 )	2023-03-03 12:22:49 +00:00
Patrick Cloke	7ae4f7236a	Configure ruff to automatically fix issues. (#15194 )	2023-03-03 07:13:03 -05:00
Andrew Morgan	15e975f68f	Experimental MSC3890 Implementation: Fix deleting account data when using an account data writer worker (#14869 )	2023-03-03 10:51:57 +00:00
Andrew Morgan	1eea662780	Add a `get_next_txn` method to `StreamIdGenerator` to match `MultiWriterIdGenerator` (#15191	2023-03-02 18:27:00 +00:00
Dirk Klimpel	ecbe0ddbe7	Add support for knocking to workers. (#15133 )	2023-03-02 12:59:53 -05:00
Quentin Gliech	c8665dd25d	Remove the unspecced and bugged PUT /knock/{roomIdOrAlias} endpoint (#15189 )	2023-03-02 17:16:54 +00:00
David Robertson	c4f4dc35cd	Dockerfile-workers: spell out when config isn't generated (#15186 ) * Complement: Spell out when config isn't generated * Changelog	2023-03-02 15:55:26 +00:00
Patrick Cloke	8ef324ea6f	Update intentional mentions (MSC3952) to depend on `exact_event_property_contains` (MSC3966). (#15051 ) This replaces the specific `is_user_mention` push rule condition used in MSC3952 with the generic `exact_event_property_contains` push rule condition from MSC3966.	2023-03-02 08:30:51 -05:00
Patrick Cloke	33a85cf08c	Fix conflicting URLs for dehydrated devices. (#15180 )	2023-03-02 07:24:29 -05:00
Quentin Gliech	7ec1f096d3	Add Sytest jobs with the asyncio reactor enabled (#14101 )	2023-03-02 11:14:44 +00:00
Dirk Klimpel	65f10afb64	Move event_reports to `RoomWorkerStore` (#15165 )	2023-03-02 10:38:46 +00:00
Hugh Nimmo-Smith	916b8061d2	Implementation of MSC3967: Don't require UIA for initial upload of cross signing keys (#15077 )	2023-03-02 10:34:59 +00:00
				`@@ -1 +0,0 @@`
				`Batch up storing state groups when creating a new room.`
				`@@ -1 +0,0 @@`
				Add two new Third Party Rules module API callbacks: [`on_add_user_third_party_identifier`](https://matrix-org.github.io/synapse/v1.79/modules/third_party_rules_callbacks.html#on_add_user_third_party_identifier) and [`on_remove_user_third_party_identifier`](https://matrix-org.github.io/synapse/v1.79/modules/third_party_rules_callbacks.html#on_remove_user_third_party_identifier).
				`@@ -1 +0,0 @@`
				Clarify which worker processes the ThirdPartyRules' [`on_new_event`](https://matrix-org.github.io/synapse/v1.78/modules/third_party_rules_callbacks.html#on_new_event) module API callback runs on.
				`@@ -1 +0,0 @@`
				`Fix a long-standing bug where Synapse handled an unspecced field on push rules.`
				`@@ -1 +0,0 @@`
				`Fix a long-standing bug where a URL preview would break if the discovered oEmbed failed to download.`
				`@@ -1 +0,0 @@`
				Remove the unspecced `room_alias` field from the [`/createRoom`](https://spec.matrix.org/v1.6/client-server-api/#post_matrixclientv3createroom) response.
				`@@ -1 +0,0 @@`
				Refactor writing json data in `FileExfiltrationWriter`.
				`@@ -1 +0,0 @@`
				`Add media information to the command line [user data export tool](https://matrix-org.github.io/synapse/v1.79/usage/administration/admin_faq.html#how-can-i-export-user-data).`
				`@@ -1 +0,0 @@`
				`Document using [Shibboleth](https://www.shibboleth.net/) as an OpenID Provider.`