Revert accidental fast-forward merge from v1.49.0rc1

Revert "Sort internal changes in changelog"
Revert "Update CHANGES.md"
Revert "1.49.0rc1"
Revert "Revert "Move `glob_to_regex` and `re_word_boundary` to `matrix-python-common` (#11505) (#11527)"
Revert "Refactors in `_generate_sync_entry_for_rooms` (#11515)"
Revert "Correctly register shutdown handler for presence workers (#11518)"
Revert "Fix `ModuleApi.looping_background_call` for non-async functions (#11524)"
Revert "Fix 'delete room' admin api to work on incomplete rooms (#11523)"
Revert "Correctly ignore invites from ignored users (#11511)"
Revert "Fix the test breakage introduced by #11435 as a result of concurrent PRs (#11522)"
Revert "Stabilise support for MSC2918 refresh tokens as they have now been merged into the Matrix specification. (#11435)"
Revert "Save the OIDC session ID (sid) with the device on login (#11482)"
Revert "Add admin API to get some information about federation status (#11407)"
Revert "Include bundled aggregations in /sync and related fixes (#11478)"
Revert "Move `glob_to_regex` and `re_word_boundary` to `matrix-python-common` (#11505)"
Revert "Update backward extremity docs to make it clear that it does not indicate whether we have fetched an events' `prev_events` (#11469)"
Revert "Support configuring the lifetime of non-refreshable access tokens separately to refreshable access tokens. (#11445)"
Revert "Add type hints to `synapse/tests/rest/admin` (#11501)"
Revert "Revert accidental commits to develop."
Revert "Newsfile"
Revert "Give `tests.server.setup_test_homeserver` (nominally!) the same behaviour"
Revert "Move `tests.utils.setup_test_homeserver` to `tests.server`"
Revert "Convert one of the `setup_test_homeserver`s to `make_test_homeserver_synchronous`"
Revert "Disambiguate queries on `state_key` (#11497)"
Revert "Comments on the /sync tentacles (#11494)"
Revert "Clean up tests.storage.test_appservice (#11492)"
Revert "Clean up `tests.storage.test_main` to remove use of legacy code. (#11493)"
Revert "Clean up `tests.test_visibility` to remove legacy code. (#11495)"
Revert "Minor cleanup on recently ported doc pages  (#11466)"
Revert "Add most of the missing type hints to `synapse.federation`. (#11483)"
Revert "Avoid waiting for zombie processes in `synctl stop` (#11490)"
Revert "Fix media repository failing when media store path contains symlinks (#11446)"
Revert "Add type annotations to `tests.storage.test_appservice`. (#11488)"
Revert "`scripts-dev/sign_json`: support for signing events (#11486)"
Revert "Add MSC3030 experimental client and federation API endpoints to get the closest event to a given timestamp (#9445)"
Revert "Port wiki pages to documentation website (#11402)"
Revert "Add a license header and comment. (#11479)"
Revert "Clean-up get_version_string (#11468)"
Revert "Link background update controller docs to summary (#11475)"
Revert "Additional type hints for config module. (#11465)"
Revert "Register the login redirect endpoint for v3. (#11451)"
Revert "Update openid.md"
Revert "Remove mention of OIDC certification from Dex (#11470)"
Revert "Add a note about huge pages to our Postgres doc (#11467)"
Revert "Don't start Synapse master process if `worker_app` is set (#11416)"
Revert "Expose worker & homeserver as entrypoints in `setup.py` (#11449)"
Revert "Bundle relations of relations into the `/relations` result. (#11284)"
Revert "Fix `LruCache` corruption bug with a `size_callback` that can return 0 (#11454)"
Revert "Eliminate a few `Any`s in `LruCache` type hints (#11453)"
Revert "Remove unnecessary `json.dumps` from `tests.rest.admin` (#11461)"
Revert "Merge branch 'master' into develop"

This reverts commit 26b5d2320f62b5eb6262c7614fbdfc364a4dfc02.
This reverts commit bce4220f387bf5448387f0ed7d14ed1e41e40747.
This reverts commit 966b5d0fa0893c3b628c942dfc232e285417f46d.
This reverts commit 088d748f2cb51f03f3bcacc0fb3af1e0f9607737.
This reverts commit 14d593f72d10b4d8cb67e3288bb3131ee30ccf59.
This reverts commit 2a3ec6facf79f6aae011d9fb6f9ed5e43c7b6bec.
This reverts commit eccc49d7554d1fab001e1fefb0fda8ffb254b630.
This reverts commit b1ecd19c5d19815b69e425d80f442bf2877cab76.
This reverts commit 9c55dedc8c4484e6269451a8c3c10b3e314aeb4a.
This reverts commit 2d42e586a8c54be1a83643148358b1651c1ca666.
This reverts commit 2f053f3f82ca174cc1c858c75afffae51af8ce0d.
This reverts commit a15a893df8428395df7cb95b729431575001c38a.
This reverts commit 8b4b153c9e86c04c7db8c74fde4b6a04becbc461.
This reverts commit 494ebd7347ba52d702802fba4c3bb13e7bfbc2cf.
This reverts commit a77c36989785c0d5565ab9a1169f4f88e512ce8a.
This reverts commit 4eb77965cd016181d2111f37d93526e9bb0434f0.
This reverts commit 637df95de63196033a6da4a6e286e1d58ea517b6.
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This reverts commit 6cae125e20865c52d770b24278bb7ab8fde5bc0d.
This reverts commit 7be88fbf48156b36b6daefb228e1258e7d48cae4.
This reverts commit b3fd99b74a3f6f42a9afd1b19ee4c60e38e8e91a.
This reverts commit f7ec6e7d9e0dc360d9fb41f3a1afd7bdba1475c7.
This reverts commit 5640992d176a499204a0756b1677c9b1575b0a49.
This reverts commit d26808dd854006bd26a2366c675428ce0737238c.
This reverts commit f91624a5950e14ba9007eed9bfa1c828676d4745.
This reverts commit 16d39a5490ce74c901c7a8dbb990c6e83c379207.
This reverts commit 8a4c2969874c0b7d72003f2523883eba8a348e83.
This reverts commit 49e1356ee3d5d72929c91f778b3a231726c1413c.
This reverts commit d2279f471ba8f44d9f578e62b286897a338d8aa1.
This reverts commit b50e39df578adc3f86c5efa16bee9035cfdab61b.
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This reverts commit b9fef1a7cdfcc128fa589a32160e6aa7ed8964d7.
This reverts commit b0eb64ff7bf6bde42046e091f8bdea9b7aab5f04.
This reverts commit f1795463bf503a6fca909d77f598f641f9349f56.
This reverts commit 70cbb1a5e311f609b624e3fae1a1712db639c51e.
This reverts commit 42bf0204635213e2c75188b19ee66dc7e7d8a35e.
This reverts commit 379f2650cf875f50c59524147ec0e33cfd5ef60c.
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This reverts commit 432a174bc192740ac7a0a755009f6099b8363ad9.
This reverts commit b14f8a1baf6f500997ae4c1d6a6d72094ce14270, reversing
changes made to e713855dca17a7605bae99ea8d71bc7f8657e4b8.

12 files changed, 185 insertions, 418 deletions

diff --git a/synapse/rest/admin/__init__.py b/synapse/rest/admin/__init__.py
index c499afd4be..ee4a5e481b 100644
--- a/synapse/rest/admin/__init__.py
+++ b/synapse/rest/admin/__init__.py
@@ -17,7 +17,6 @@
 
 import logging
 import platform
-from http import HTTPStatus
 from typing import TYPE_CHECKING, Optional, Tuple
 
 import synapse
@@ -40,10 +39,6 @@ from synapse.rest.admin.event_reports import (
     EventReportDetailRestServlet,
     EventReportsRestServlet,
 )
-from synapse.rest.admin.federation import (
-    DestinationsRestServlet,
-    ListDestinationsRestServlet,
-)
 from synapse.rest.admin.groups import DeleteGroupAdminRestServlet
 from synapse.rest.admin.media import ListMediaInRoom, register_servlets_for_media_repo
 from synapse.rest.admin.registration_tokens import (
@@ -103,7 +98,7 @@ class VersionServlet(RestServlet):
         }
 
     def on_GET(self, request: SynapseRequest) -> Tuple[int, JsonDict]:
-        return HTTPStatus.OK, self.res
+        return 200, self.res
 
 
 class PurgeHistoryRestServlet(RestServlet):
@@ -135,7 +130,7 @@ class PurgeHistoryRestServlet(RestServlet):
             event = await self.store.get_event(event_id)
 
             if event.room_id != room_id:
-                raise SynapseError(HTTPStatus.BAD_REQUEST, "Event is for wrong room.")
+                raise SynapseError(400, "Event is for wrong room.")
 
             # RoomStreamToken expects [int] not Optional[int]
             assert event.internal_metadata.stream_ordering is not None
@@ -149,9 +144,7 @@ class PurgeHistoryRestServlet(RestServlet):
             ts = body["purge_up_to_ts"]
             if not isinstance(ts, int):
                 raise SynapseError(
-                    HTTPStatus.BAD_REQUEST,
-                    "purge_up_to_ts must be an int",
-                    errcode=Codes.BAD_JSON,
+                    400, "purge_up_to_ts must be an int", errcode=Codes.BAD_JSON
                 )
 
             stream_ordering = await self.store.find_first_stream_ordering_after_ts(ts)
@@ -167,9 +160,7 @@ class PurgeHistoryRestServlet(RestServlet):
                     stream_ordering,
                 )
                 raise SynapseError(
-                    HTTPStatus.NOT_FOUND,
-                    "there is no event to be purged",
-                    errcode=Codes.NOT_FOUND,
+                    404, "there is no event to be purged", errcode=Codes.NOT_FOUND
                 )
             (stream, topo, _event_id) = r
             token = "t%d-%d" % (topo, stream)
@@ -182,7 +173,7 @@ class PurgeHistoryRestServlet(RestServlet):
             )
         else:
             raise SynapseError(
-                HTTPStatus.BAD_REQUEST,
+                400,
                 "must specify purge_up_to_event_id or purge_up_to_ts",
                 errcode=Codes.BAD_JSON,
             )
@@ -191,7 +182,7 @@ class PurgeHistoryRestServlet(RestServlet):
             room_id, token, delete_local_events=delete_local_events
         )
 
-        return HTTPStatus.OK, {"purge_id": purge_id}
+        return 200, {"purge_id": purge_id}
 
 
 class PurgeHistoryStatusRestServlet(RestServlet):
@@ -210,7 +201,7 @@ class PurgeHistoryStatusRestServlet(RestServlet):
         if purge_status is None:
             raise NotFoundError("purge id '%s' not found" % purge_id)
 
-        return HTTPStatus.OK, purge_status.asdict()
+        return 200, purge_status.asdict()
 
 
 ########################################################################################
@@ -265,8 +256,6 @@ def register_servlets(hs: "HomeServer", http_server: HttpServer) -> None:
     ListRegistrationTokensRestServlet(hs).register(http_server)
     NewRegistrationTokenRestServlet(hs).register(http_server)
     RegistrationTokenRestServlet(hs).register(http_server)
-    DestinationsRestServlet(hs).register(http_server)
-    ListDestinationsRestServlet(hs).register(http_server)
 
     # Some servlets only get registered for the main process.
     if hs.config.worker.worker_app is None:
diff --git a/synapse/rest/admin/_base.py b/synapse/rest/admin/_base.py
index 399b205aaf..d9a2f6ca15 100644
--- a/synapse/rest/admin/_base.py
+++ b/synapse/rest/admin/_base.py
@@ -13,7 +13,6 @@
 # limitations under the License.
 
 import re
-from http import HTTPStatus
 from typing import Iterable, Pattern
 
 from synapse.api.auth import Auth
@@ -63,4 +62,4 @@ async def assert_user_is_admin(auth: Auth, user_id: UserID) -> None:
     """
     is_admin = await auth.is_server_admin(user_id)
     if not is_admin:
-        raise AuthError(HTTPStatus.FORBIDDEN, "You are not a server admin")
+        raise AuthError(403, "You are not a server admin")
diff --git a/synapse/rest/admin/devices.py b/synapse/rest/admin/devices.py
index 2e5a6600d3..80fbf32f17 100644
--- a/synapse/rest/admin/devices.py
+++ b/synapse/rest/admin/devices.py
@@ -12,7 +12,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 import logging
-from http import HTTPStatus
 from typing import TYPE_CHECKING, Tuple
 
 from synapse.api.errors import NotFoundError, SynapseError
@@ -54,7 +53,7 @@ class DeviceRestServlet(RestServlet):
 
         target_user = UserID.from_string(user_id)
         if not self.hs.is_mine(target_user):
-            raise SynapseError(HTTPStatus.BAD_REQUEST, "Can only lookup local users")
+            raise SynapseError(400, "Can only lookup local users")
 
         u = await self.store.get_user_by_id(target_user.to_string())
         if u is None:
@@ -63,7 +62,7 @@ class DeviceRestServlet(RestServlet):
         device = await self.device_handler.get_device(
             target_user.to_string(), device_id
         )
-        return HTTPStatus.OK, device
+        return 200, device
 
     async def on_DELETE(
         self, request: SynapseRequest, user_id: str, device_id: str
@@ -72,14 +71,14 @@ class DeviceRestServlet(RestServlet):
 
         target_user = UserID.from_string(user_id)
         if not self.hs.is_mine(target_user):
-            raise SynapseError(HTTPStatus.BAD_REQUEST, "Can only lookup local users")
+            raise SynapseError(400, "Can only lookup local users")
 
         u = await self.store.get_user_by_id(target_user.to_string())
         if u is None:
             raise NotFoundError("Unknown user")
 
         await self.device_handler.delete_device(target_user.to_string(), device_id)
-        return HTTPStatus.OK, {}
+        return 200, {}
 
     async def on_PUT(
         self, request: SynapseRequest, user_id: str, device_id: str
@@ -88,7 +87,7 @@ class DeviceRestServlet(RestServlet):
 
         target_user = UserID.from_string(user_id)
         if not self.hs.is_mine(target_user):
-            raise SynapseError(HTTPStatus.BAD_REQUEST, "Can only lookup local users")
+            raise SynapseError(400, "Can only lookup local users")
 
         u = await self.store.get_user_by_id(target_user.to_string())
         if u is None:
@@ -98,7 +97,7 @@ class DeviceRestServlet(RestServlet):
         await self.device_handler.update_device(
             target_user.to_string(), device_id, body
         )
-        return HTTPStatus.OK, {}
+        return 200, {}
 
 
 class DevicesRestServlet(RestServlet):
@@ -125,14 +124,14 @@ class DevicesRestServlet(RestServlet):
 
         target_user = UserID.from_string(user_id)
         if not self.hs.is_mine(target_user):
-            raise SynapseError(HTTPStatus.BAD_REQUEST, "Can only lookup local users")
+            raise SynapseError(400, "Can only lookup local users")
 
         u = await self.store.get_user_by_id(target_user.to_string())
         if u is None:
             raise NotFoundError("Unknown user")
 
         devices = await self.device_handler.get_devices_by_user(target_user.to_string())
-        return HTTPStatus.OK, {"devices": devices, "total": len(devices)}
+        return 200, {"devices": devices, "total": len(devices)}
 
 
 class DeleteDevicesRestServlet(RestServlet):
@@ -156,7 +155,7 @@ class DeleteDevicesRestServlet(RestServlet):
 
         target_user = UserID.from_string(user_id)
         if not self.hs.is_mine(target_user):
-            raise SynapseError(HTTPStatus.BAD_REQUEST, "Can only lookup local users")
+            raise SynapseError(400, "Can only lookup local users")
 
         u = await self.store.get_user_by_id(target_user.to_string())
         if u is None:
@@ -168,4 +167,4 @@ class DeleteDevicesRestServlet(RestServlet):
         await self.device_handler.delete_devices(
             target_user.to_string(), body["devices"]
         )
-        return HTTPStatus.OK, {}
+        return 200, {}
diff --git a/synapse/rest/admin/event_reports.py b/synapse/rest/admin/event_reports.py
index 5ee8b11110..bbfcaf723b 100644
--- a/synapse/rest/admin/event_reports.py
+++ b/synapse/rest/admin/event_reports.py
@@ -13,7 +13,6 @@
 # limitations under the License.
 
 import logging
-from http import HTTPStatus
 from typing import TYPE_CHECKING, Tuple
 
 from synapse.api.errors import Codes, NotFoundError, SynapseError
@@ -67,23 +66,21 @@ class EventReportsRestServlet(RestServlet):
 
         if start < 0:
             raise SynapseError(
-                HTTPStatus.BAD_REQUEST,
+                400,
                 "The start parameter must be a positive integer.",
                 errcode=Codes.INVALID_PARAM,
             )
 
         if limit < 0:
             raise SynapseError(
-                HTTPStatus.BAD_REQUEST,
+                400,
                 "The limit parameter must be a positive integer.",
                 errcode=Codes.INVALID_PARAM,
             )
 
         if direction not in ("f", "b"):
             raise SynapseError(
-                HTTPStatus.BAD_REQUEST,
-                "Unknown direction: %s" % (direction,),
-                errcode=Codes.INVALID_PARAM,
+                400, "Unknown direction: %s" % (direction,), errcode=Codes.INVALID_PARAM
             )
 
         event_reports, total = await self.store.get_event_reports_paginate(
@@ -93,7 +90,7 @@ class EventReportsRestServlet(RestServlet):
         if (start + limit) < total:
             ret["next_token"] = start + len(event_reports)
 
-        return HTTPStatus.OK, ret
+        return 200, ret
 
 
 class EventReportDetailRestServlet(RestServlet):
@@ -130,17 +127,13 @@ class EventReportDetailRestServlet(RestServlet):
         try:
             resolved_report_id = int(report_id)
         except ValueError:
-            raise SynapseError(
-                HTTPStatus.BAD_REQUEST, message, errcode=Codes.INVALID_PARAM
-            )
+            raise SynapseError(400, message, errcode=Codes.INVALID_PARAM)
 
         if resolved_report_id < 0:
-            raise SynapseError(
-                HTTPStatus.BAD_REQUEST, message, errcode=Codes.INVALID_PARAM
-            )
+            raise SynapseError(400, message, errcode=Codes.INVALID_PARAM)
 
         ret = await self.store.get_event_report(resolved_report_id)
         if not ret:
             raise NotFoundError("Event report not found")
 
-        return HTTPStatus.OK, ret
+        return 200, ret
diff --git a/synapse/rest/admin/federation.py b/synapse/rest/admin/federation.py
deleted file mode 100644
index 744687be35..0000000000
--- a/synapse/rest/admin/federation.py
+++ /dev/null
@@ -1,135 +0,0 @@
-# Copyright 2021 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 http import HTTPStatus
-from typing import TYPE_CHECKING, Tuple
-
-from synapse.api.errors import Codes, NotFoundError, SynapseError
-from synapse.http.servlet import RestServlet, parse_integer, parse_string
-from synapse.http.site import SynapseRequest
-from synapse.rest.admin._base import admin_patterns, assert_requester_is_admin
-from synapse.storage.databases.main.transactions import DestinationSortOrder
-from synapse.types import JsonDict
-
-if TYPE_CHECKING:
-    from synapse.server import HomeServer
-
-logger = logging.getLogger(__name__)
-
-
-class ListDestinationsRestServlet(RestServlet):
-    """Get request to list all destinations.
-    This needs user to have administrator access in Synapse.
-
-    GET /_synapse/admin/v1/federation/destinations?from=0&limit=10
-
-    returns:
-        200 OK with list of destinations if success otherwise an error.
-
-    The parameters `from` and `limit` are required only for pagination.
-    By default, a `limit` of 100 is used.
-    The parameter `destination` can be used to filter by destination.
-    The parameter `order_by` can be used to order the result.
-    """
-
-    PATTERNS = admin_patterns("/federation/destinations$")
-
-    def __init__(self, hs: "HomeServer"):
-        self._auth = hs.get_auth()
-        self._store = hs.get_datastore()
-
-    async def on_GET(self, request: SynapseRequest) -> Tuple[int, JsonDict]:
-        await assert_requester_is_admin(self._auth, request)
-
-        start = parse_integer(request, "from", default=0)
-        limit = parse_integer(request, "limit", default=100)
-
-        if start < 0:
-            raise SynapseError(
-                HTTPStatus.BAD_REQUEST,
-                "Query parameter from must be a string representing a positive integer.",
-                errcode=Codes.INVALID_PARAM,
-            )
-
-        if limit < 0:
-            raise SynapseError(
-                HTTPStatus.BAD_REQUEST,
-                "Query parameter limit must be a string representing a positive integer.",
-                errcode=Codes.INVALID_PARAM,
-            )
-
-        destination = parse_string(request, "destination")
-
-        order_by = parse_string(
-            request,
-            "order_by",
-            default=DestinationSortOrder.DESTINATION.value,
-            allowed_values=[dest.value for dest in DestinationSortOrder],
-        )
-
-        direction = parse_string(request, "dir", default="f", allowed_values=("f", "b"))
-
-        destinations, total = await self._store.get_destinations_paginate(
-            start, limit, destination, order_by, direction
-        )
-        response = {"destinations": destinations, "total": total}
-        if (start + limit) < total:
-            response["next_token"] = str(start + len(destinations))
-
-        return HTTPStatus.OK, response
-
-
-class DestinationsRestServlet(RestServlet):
-    """Get details of a destination.
-    This needs user to have administrator access in Synapse.
-
-    GET /_synapse/admin/v1/federation/destinations/<destination>
-
-    returns:
-        200 OK with details of a destination if success otherwise an error.
-    """
-
-    PATTERNS = admin_patterns("/federation/destinations/(?P<destination>[^/]+)$")
-
-    def __init__(self, hs: "HomeServer"):
-        self._auth = hs.get_auth()
-        self._store = hs.get_datastore()
-
-    async def on_GET(
-        self, request: SynapseRequest, destination: str
-    ) -> Tuple[int, JsonDict]:
-        await assert_requester_is_admin(self._auth, request)
-
-        destination_retry_timings = await self._store.get_destination_retry_timings(
-            destination
-        )
-
-        if not destination_retry_timings:
-            raise NotFoundError("Unknown destination")
-
-        last_successful_stream_ordering = (
-            await self._store.get_destination_last_successful_stream_ordering(
-                destination
-            )
-        )
-
-        response = {
-            "destination": destination,
-            "failure_ts": destination_retry_timings.failure_ts,
-            "retry_last_ts": destination_retry_timings.retry_last_ts,
-            "retry_interval": destination_retry_timings.retry_interval,
-            "last_successful_stream_ordering": last_successful_stream_ordering,
-        }
-
-        return HTTPStatus.OK, response
diff --git a/synapse/rest/admin/groups.py b/synapse/rest/admin/groups.py
index a27110388f..68a3ba3cb7 100644
--- a/synapse/rest/admin/groups.py
+++ b/synapse/rest/admin/groups.py
@@ -12,7 +12,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 import logging
-from http import HTTPStatus
 from typing import TYPE_CHECKING, Tuple
 
 from synapse.api.errors import SynapseError
@@ -44,7 +43,7 @@ class DeleteGroupAdminRestServlet(RestServlet):
         await assert_user_is_admin(self.auth, requester.user)
 
         if not self.is_mine_id(group_id):
-            raise SynapseError(HTTPStatus.BAD_REQUEST, "Can only delete local groups")
+            raise SynapseError(400, "Can only delete local groups")
 
         await self.group_server.delete_group(group_id, requester.user.to_string())
-        return HTTPStatus.OK, {}
+        return 200, {}
diff --git a/synapse/rest/admin/media.py b/synapse/rest/admin/media.py
index 9e23e2d8fc..30a687d234 100644
--- a/synapse/rest/admin/media.py
+++ b/synapse/rest/admin/media.py
@@ -14,7 +14,6 @@
 # limitations under the License.
 
 import logging
-from http import HTTPStatus
 from typing import TYPE_CHECKING, Tuple
 
 from synapse.api.errors import AuthError, Codes, NotFoundError, SynapseError
@@ -63,7 +62,7 @@ class QuarantineMediaInRoom(RestServlet):
             room_id, requester.user.to_string()
         )
 
-        return HTTPStatus.OK, {"num_quarantined": num_quarantined}
+        return 200, {"num_quarantined": num_quarantined}
 
 
 class QuarantineMediaByUser(RestServlet):
@@ -90,7 +89,7 @@ class QuarantineMediaByUser(RestServlet):
             user_id, requester.user.to_string()
         )
 
-        return HTTPStatus.OK, {"num_quarantined": num_quarantined}
+        return 200, {"num_quarantined": num_quarantined}
 
 
 class QuarantineMediaByID(RestServlet):
@@ -119,7 +118,7 @@ class QuarantineMediaByID(RestServlet):
             server_name, media_id, requester.user.to_string()
         )
 
-        return HTTPStatus.OK, {}
+        return 200, {}
 
 
 class UnquarantineMediaByID(RestServlet):
@@ -148,7 +147,7 @@ class UnquarantineMediaByID(RestServlet):
         # Remove from quarantine this media id
         await self.store.quarantine_media_by_id(server_name, media_id, None)
 
-        return HTTPStatus.OK, {}
+        return 200, {}
 
 
 class ProtectMediaByID(RestServlet):
@@ -171,7 +170,7 @@ class ProtectMediaByID(RestServlet):
         # Protect this media id
         await self.store.mark_local_media_as_safe(media_id, safe=True)
 
-        return HTTPStatus.OK, {}
+        return 200, {}
 
 
 class UnprotectMediaByID(RestServlet):
@@ -194,7 +193,7 @@ class UnprotectMediaByID(RestServlet):
         # Unprotect this media id
         await self.store.mark_local_media_as_safe(media_id, safe=False)
 
-        return HTTPStatus.OK, {}
+        return 200, {}
 
 
 class ListMediaInRoom(RestServlet):
@@ -212,11 +211,11 @@ class ListMediaInRoom(RestServlet):
         requester = await self.auth.get_user_by_req(request)
         is_admin = await self.auth.is_server_admin(requester.user)
         if not is_admin:
-            raise AuthError(HTTPStatus.FORBIDDEN, "You are not a server admin")
+            raise AuthError(403, "You are not a server admin")
 
         local_mxcs, remote_mxcs = await self.store.get_media_mxcs_in_room(room_id)
 
-        return HTTPStatus.OK, {"local": local_mxcs, "remote": remote_mxcs}
+        return 200, {"local": local_mxcs, "remote": remote_mxcs}
 
 
 class PurgeMediaCacheRestServlet(RestServlet):
@@ -234,13 +233,13 @@ class PurgeMediaCacheRestServlet(RestServlet):
 
         if before_ts < 0:
             raise SynapseError(
-                HTTPStatus.BAD_REQUEST,
+                400,
                 "Query parameter before_ts must be a positive integer.",
                 errcode=Codes.INVALID_PARAM,
             )
         elif before_ts < 30000000000:  # Dec 1970 in milliseconds, Aug 2920 in seconds
             raise SynapseError(
-                HTTPStatus.BAD_REQUEST,
+                400,
                 "Query parameter before_ts you provided is from the year 1970. "
                 + "Double check that you are providing a timestamp in milliseconds.",
                 errcode=Codes.INVALID_PARAM,
@@ -248,7 +247,7 @@ class PurgeMediaCacheRestServlet(RestServlet):
 
         ret = await self.media_repository.delete_old_remote_media(before_ts)
 
-        return HTTPStatus.OK, ret
+        return 200, ret
 
 
 class DeleteMediaByID(RestServlet):
@@ -268,7 +267,7 @@ class DeleteMediaByID(RestServlet):
         await assert_requester_is_admin(self.auth, request)
 
         if self.server_name != server_name:
-            raise SynapseError(HTTPStatus.BAD_REQUEST, "Can only delete local media")
+            raise SynapseError(400, "Can only delete local media")
 
         if await self.store.get_local_media(media_id) is None:
             raise NotFoundError("Unknown media")
@@ -278,7 +277,7 @@ class DeleteMediaByID(RestServlet):
         deleted_media, total = await self.media_repository.delete_local_media_ids(
             [media_id]
         )
-        return HTTPStatus.OK, {"deleted_media": deleted_media, "total": total}
+        return 200, {"deleted_media": deleted_media, "total": total}
 
 
 class DeleteMediaByDateSize(RestServlet):
@@ -305,26 +304,26 @@ class DeleteMediaByDateSize(RestServlet):
 
         if before_ts < 0:
             raise SynapseError(
-                HTTPStatus.BAD_REQUEST,
+                400,
                 "Query parameter before_ts must be a positive integer.",
                 errcode=Codes.INVALID_PARAM,
             )
         elif before_ts < 30000000000:  # Dec 1970 in milliseconds, Aug 2920 in seconds
             raise SynapseError(
-                HTTPStatus.BAD_REQUEST,
+                400,
                 "Query parameter before_ts you provided is from the year 1970. "
                 + "Double check that you are providing a timestamp in milliseconds.",
                 errcode=Codes.INVALID_PARAM,
             )
         if size_gt < 0:
             raise SynapseError(
-                HTTPStatus.BAD_REQUEST,
+                400,
                 "Query parameter size_gt must be a string representing a positive integer.",
                 errcode=Codes.INVALID_PARAM,
             )
 
         if self.server_name != server_name:
-            raise SynapseError(HTTPStatus.BAD_REQUEST, "Can only delete local media")
+            raise SynapseError(400, "Can only delete local media")
 
         logging.info(
             "Deleting local media by timestamp: %s, size larger than: %s, keep profile media: %s"
@@ -334,7 +333,7 @@ class DeleteMediaByDateSize(RestServlet):
         deleted_media, total = await self.media_repository.delete_old_local_media(
             before_ts, size_gt, keep_profiles
         )
-        return HTTPStatus.OK, {"deleted_media": deleted_media, "total": total}
+        return 200, {"deleted_media": deleted_media, "total": total}
 
 
 class UserMediaRestServlet(RestServlet):
@@ -370,7 +369,7 @@ class UserMediaRestServlet(RestServlet):
         await assert_requester_is_admin(self.auth, request)
 
         if not self.is_mine(UserID.from_string(user_id)):
-            raise SynapseError(HTTPStatus.BAD_REQUEST, "Can only look up local users")
+            raise SynapseError(400, "Can only look up local users")
 
         user = await self.store.get_user_by_id(user_id)
         if user is None:
@@ -381,14 +380,14 @@ class UserMediaRestServlet(RestServlet):
 
         if start < 0:
             raise SynapseError(
-                HTTPStatus.BAD_REQUEST,
+                400,
                 "Query parameter from must be a string representing a positive integer.",
                 errcode=Codes.INVALID_PARAM,
             )
 
         if limit < 0:
             raise SynapseError(
-                HTTPStatus.BAD_REQUEST,
+                400,
                 "Query parameter limit must be a string representing a positive integer.",
                 errcode=Codes.INVALID_PARAM,
             )
@@ -426,7 +425,7 @@ class UserMediaRestServlet(RestServlet):
         if (start + limit) < total:
             ret["next_token"] = start + len(media)
 
-        return HTTPStatus.OK, ret
+        return 200, ret
 
     async def on_DELETE(
         self, request: SynapseRequest, user_id: str
@@ -437,7 +436,7 @@ class UserMediaRestServlet(RestServlet):
         await assert_requester_is_admin(self.auth, request)
 
         if not self.is_mine(UserID.from_string(user_id)):
-            raise SynapseError(HTTPStatus.BAD_REQUEST, "Can only look up local users")
+            raise SynapseError(400, "Can only look up local users")
 
         user = await self.store.get_user_by_id(user_id)
         if user is None:
@@ -448,14 +447,14 @@ class UserMediaRestServlet(RestServlet):
 
         if start < 0:
             raise SynapseError(
-                HTTPStatus.BAD_REQUEST,
+                400,
                 "Query parameter from must be a string representing a positive integer.",
                 errcode=Codes.INVALID_PARAM,
             )
 
         if limit < 0:
             raise SynapseError(
-                HTTPStatus.BAD_REQUEST,
+                400,
                 "Query parameter limit must be a string representing a positive integer.",
                 errcode=Codes.INVALID_PARAM,
             )
@@ -493,7 +492,7 @@ class UserMediaRestServlet(RestServlet):
             ([row["media_id"] for row in media])
         )
 
-        return HTTPStatus.OK, {"deleted_media": deleted_media, "total": total}
+        return 200, {"deleted_media": deleted_media, "total": total}
 
 
 def register_servlets_for_media_repo(hs: "HomeServer", http_server: HttpServer) -> None:
diff --git a/synapse/rest/admin/registration_tokens.py b/synapse/rest/admin/registration_tokens.py
index 891b98c088..aba48f6e7b 100644
--- a/synapse/rest/admin/registration_tokens.py
+++ b/synapse/rest/admin/registration_tokens.py
@@ -14,7 +14,6 @@
 
 import logging
 import string
-from http import HTTPStatus
 from typing import TYPE_CHECKING, Tuple
 
 from synapse.api.errors import Codes, NotFoundError, SynapseError
@@ -78,7 +77,7 @@ class ListRegistrationTokensRestServlet(RestServlet):
         await assert_requester_is_admin(self.auth, request)
         valid = parse_boolean(request, "valid")
         token_list = await self.store.get_registration_tokens(valid)
-        return HTTPStatus.OK, {"registration_tokens": token_list}
+        return 200, {"registration_tokens": token_list}
 
 
 class NewRegistrationTokenRestServlet(RestServlet):
@@ -124,20 +123,16 @@ class NewRegistrationTokenRestServlet(RestServlet):
         if "token" in body:
             token = body["token"]
             if not isinstance(token, str):
-                raise SynapseError(
-                    HTTPStatus.BAD_REQUEST,
-                    "token must be a string",
-                    Codes.INVALID_PARAM,
-                )
+                raise SynapseError(400, "token must be a string", Codes.INVALID_PARAM)
             if not (0 < len(token) <= 64):
                 raise SynapseError(
-                    HTTPStatus.BAD_REQUEST,
+                    400,
                     "token must not be empty and must not be longer than 64 characters",
                     Codes.INVALID_PARAM,
                 )
             if not set(token).issubset(self.allowed_chars_set):
                 raise SynapseError(
-                    HTTPStatus.BAD_REQUEST,
+                    400,
                     "token must consist only of characters matched by the regex [A-Za-z0-9-_]",
                     Codes.INVALID_PARAM,
                 )
@@ -147,13 +142,11 @@ class NewRegistrationTokenRestServlet(RestServlet):
             length = body.get("length", 16)
             if not isinstance(length, int):
                 raise SynapseError(
-                    HTTPStatus.BAD_REQUEST,
-                    "length must be an integer",
-                    Codes.INVALID_PARAM,
+                    400, "length must be an integer", Codes.INVALID_PARAM
                 )
             if not (0 < length <= 64):
                 raise SynapseError(
-                    HTTPStatus.BAD_REQUEST,
+                    400,
                     "length must be greater than zero and not greater than 64",
                     Codes.INVALID_PARAM,
                 )
@@ -169,7 +162,7 @@ class NewRegistrationTokenRestServlet(RestServlet):
             or (isinstance(uses_allowed, int) and uses_allowed >= 0)
         ):
             raise SynapseError(
-                HTTPStatus.BAD_REQUEST,
+                400,
                 "uses_allowed must be a non-negative integer or null",
                 Codes.INVALID_PARAM,
             )
@@ -177,15 +170,11 @@ class NewRegistrationTokenRestServlet(RestServlet):
         expiry_time = body.get("expiry_time", None)
         if not isinstance(expiry_time, (int, type(None))):
             raise SynapseError(
-                HTTPStatus.BAD_REQUEST,
-                "expiry_time must be an integer or null",
-                Codes.INVALID_PARAM,
+                400, "expiry_time must be an integer or null", Codes.INVALID_PARAM
             )
         if isinstance(expiry_time, int) and expiry_time < self.clock.time_msec():
             raise SynapseError(
-                HTTPStatus.BAD_REQUEST,
-                "expiry_time must not be in the past",
-                Codes.INVALID_PARAM,
+                400, "expiry_time must not be in the past", Codes.INVALID_PARAM
             )
 
         created = await self.store.create_registration_token(
@@ -193,9 +182,7 @@ class NewRegistrationTokenRestServlet(RestServlet):
         )
         if not created:
             raise SynapseError(
-                HTTPStatus.BAD_REQUEST,
-                f"Token already exists: {token}",
-                Codes.INVALID_PARAM,
+                400, f"Token already exists: {token}", Codes.INVALID_PARAM
             )
 
         resp = {
@@ -205,7 +192,7 @@ class NewRegistrationTokenRestServlet(RestServlet):
             "completed": 0,
             "expiry_time": expiry_time,
         }
-        return HTTPStatus.OK, resp
+        return 200, resp
 
 
 class RegistrationTokenRestServlet(RestServlet):
@@ -274,7 +261,7 @@ class RegistrationTokenRestServlet(RestServlet):
         if token_info is None:
             raise NotFoundError(f"No such registration token: {token}")
 
-        return HTTPStatus.OK, token_info
+        return 200, token_info
 
     async def on_PUT(self, request: SynapseRequest, token: str) -> Tuple[int, JsonDict]:
         """Update a registration token."""
@@ -290,7 +277,7 @@ class RegistrationTokenRestServlet(RestServlet):
                 or (isinstance(uses_allowed, int) and uses_allowed >= 0)
             ):
                 raise SynapseError(
-                    HTTPStatus.BAD_REQUEST,
+                    400,
                     "uses_allowed must be a non-negative integer or null",
                     Codes.INVALID_PARAM,
                 )
@@ -300,15 +287,11 @@ class RegistrationTokenRestServlet(RestServlet):
             expiry_time = body["expiry_time"]
             if not isinstance(expiry_time, (int, type(None))):
                 raise SynapseError(
-                    HTTPStatus.BAD_REQUEST,
-                    "expiry_time must be an integer or null",
-                    Codes.INVALID_PARAM,
+                    400, "expiry_time must be an integer or null", Codes.INVALID_PARAM
                 )
             if isinstance(expiry_time, int) and expiry_time < self.clock.time_msec():
                 raise SynapseError(
-                    HTTPStatus.BAD_REQUEST,
-                    "expiry_time must not be in the past",
-                    Codes.INVALID_PARAM,
+                    400, "expiry_time must not be in the past", Codes.INVALID_PARAM
                 )
             new_attributes["expiry_time"] = expiry_time
 
@@ -324,7 +307,7 @@ class RegistrationTokenRestServlet(RestServlet):
         if token_info is None:
             raise NotFoundError(f"No such registration token: {token}")
 
-        return HTTPStatus.OK, token_info
+        return 200, token_info
 
     async def on_DELETE(
         self, request: SynapseRequest, token: str
@@ -333,6 +316,6 @@ class RegistrationTokenRestServlet(RestServlet):
         await assert_requester_is_admin(self.auth, request)
 
         if await self.store.delete_registration_token(token):
-            return HTTPStatus.OK, {}
+            return 200, {}
 
         raise NotFoundError(f"No such registration token: {token}")
diff --git a/synapse/rest/admin/rooms.py b/synapse/rest/admin/rooms.py
index 829e86675a..a89dda1ba5 100644
--- a/synapse/rest/admin/rooms.py
+++ b/synapse/rest/admin/rooms.py
@@ -102,9 +102,10 @@ class RoomRestV2Servlet(RestServlet):
             )
 
         if not RoomID.is_valid(room_id):
-            raise SynapseError(
-                HTTPStatus.BAD_REQUEST, "%s is not a legal room ID" % (room_id,)
-            )
+            raise SynapseError(400, "%s is not a legal room ID" % (room_id,))
+
+        if not await self._store.get_room(room_id):
+            raise NotFoundError("Unknown room id %s" % (room_id,))
 
         delete_id = self._pagination_handler.start_shutdown_and_purge_room(
             room_id=room_id,
@@ -117,7 +118,7 @@ class RoomRestV2Servlet(RestServlet):
             force_purge=force_purge,
         )
 
-        return HTTPStatus.OK, {"delete_id": delete_id}
+        return 200, {"delete_id": delete_id}
 
 
 class DeleteRoomStatusByRoomIdRestServlet(RestServlet):
@@ -136,9 +137,7 @@ class DeleteRoomStatusByRoomIdRestServlet(RestServlet):
         await assert_requester_is_admin(self._auth, request)
 
         if not RoomID.is_valid(room_id):
-            raise SynapseError(
-                HTTPStatus.BAD_REQUEST, "%s is not a legal room ID" % (room_id,)
-            )
+            raise SynapseError(400, "%s is not a legal room ID" % (room_id,))
 
         delete_ids = self._pagination_handler.get_delete_ids_by_room(room_id)
         if delete_ids is None:
@@ -154,7 +153,7 @@ class DeleteRoomStatusByRoomIdRestServlet(RestServlet):
                         **delete.asdict(),
                     }
                 ]
-        return HTTPStatus.OK, {"results": cast(JsonDict, response)}
+        return 200, {"results": cast(JsonDict, response)}
 
 
 class DeleteRoomStatusByDeleteIdRestServlet(RestServlet):
@@ -176,7 +175,7 @@ class DeleteRoomStatusByDeleteIdRestServlet(RestServlet):
         if delete_status is None:
             raise NotFoundError("delete id '%s' not found" % delete_id)
 
-        return HTTPStatus.OK, cast(JsonDict, delete_status.asdict())
+        return 200, cast(JsonDict, delete_status.asdict())
 
 
 class ListRoomRestServlet(RestServlet):
@@ -218,7 +217,7 @@ class ListRoomRestServlet(RestServlet):
             RoomSortOrder.STATE_EVENTS.value,
         ):
             raise SynapseError(
-                HTTPStatus.BAD_REQUEST,
+                400,
                 "Unknown value for order_by: %s" % (order_by,),
                 errcode=Codes.INVALID_PARAM,
             )
@@ -226,7 +225,7 @@ class ListRoomRestServlet(RestServlet):
         search_term = parse_string(request, "search_term", encoding="utf-8")
         if search_term == "":
             raise SynapseError(
-                HTTPStatus.BAD_REQUEST,
+                400,
                 "search_term cannot be an empty string",
                 errcode=Codes.INVALID_PARAM,
             )
@@ -234,9 +233,7 @@ class ListRoomRestServlet(RestServlet):
         direction = parse_string(request, "dir", default="f")
         if direction not in ("f", "b"):
             raise SynapseError(
-                HTTPStatus.BAD_REQUEST,
-                "Unknown direction: %s" % (direction,),
-                errcode=Codes.INVALID_PARAM,
+                400, "Unknown direction: %s" % (direction,), errcode=Codes.INVALID_PARAM
             )
 
         reverse_order = True if direction == "b" else False
@@ -268,7 +265,7 @@ class ListRoomRestServlet(RestServlet):
             else:
                 response["prev_batch"] = 0
 
-        return HTTPStatus.OK, response
+        return 200, response
 
 
 class RoomRestServlet(RestServlet):
@@ -313,7 +310,7 @@ class RoomRestServlet(RestServlet):
         members = await self.store.get_users_in_room(room_id)
         ret["joined_local_devices"] = await self.store.count_devices_by_users(members)
 
-        return HTTPStatus.OK, ret
+        return 200, ret
 
     async def on_DELETE(
         self, request: SynapseRequest, room_id: str
@@ -389,7 +386,7 @@ class RoomRestServlet(RestServlet):
         # See https://github.com/python/mypy/issues/4976#issuecomment-579883622
         # for some discussion on why this is necessary. Either way,
         # `ret` is an opaque dictionary blob as far as the rest of the app cares.
-        return HTTPStatus.OK, cast(JsonDict, ret)
+        return 200, cast(JsonDict, ret)
 
 
 class RoomMembersRestServlet(RestServlet):
@@ -416,7 +413,7 @@ class RoomMembersRestServlet(RestServlet):
         members = await self.store.get_users_in_room(room_id)
         ret = {"members": members, "total": len(members)}
 
-        return HTTPStatus.OK, ret
+        return 200, ret
 
 
 class RoomStateRestServlet(RestServlet):
@@ -446,10 +443,16 @@ class RoomStateRestServlet(RestServlet):
         event_ids = await self.store.get_current_state_ids(room_id)
         events = await self.store.get_events(event_ids.values())
         now = self.clock.time_msec()
-        room_state = await self._event_serializer.serialize_events(events.values(), now)
+        room_state = await self._event_serializer.serialize_events(
+            events.values(),
+            now,
+            # We don't bother bundling aggregations in when asked for state
+            # events, as clients won't use them.
+            bundle_relations=False,
+        )
         ret = {"state": room_state}
 
-        return HTTPStatus.OK, ret
+        return 200, ret
 
 
 class JoinRoomAliasServlet(ResolveRoomIdMixin, RestServlet):
@@ -478,10 +481,7 @@ class JoinRoomAliasServlet(ResolveRoomIdMixin, RestServlet):
         target_user = UserID.from_string(content["user_id"])
 
         if not self.hs.is_mine(target_user):
-            raise SynapseError(
-                HTTPStatus.BAD_REQUEST,
-                "This endpoint can only be used with local users",
-            )
+            raise SynapseError(400, "This endpoint can only be used with local users")
 
         if not await self.admin_handler.get_user(target_user):
             raise NotFoundError("User not found")
@@ -527,7 +527,7 @@ class JoinRoomAliasServlet(ResolveRoomIdMixin, RestServlet):
             ratelimit=False,
         )
 
-        return HTTPStatus.OK, {"room_id": room_id}
+        return 200, {"room_id": room_id}
 
 
 class MakeRoomAdminRestServlet(ResolveRoomIdMixin, RestServlet):
@@ -568,7 +568,7 @@ class MakeRoomAdminRestServlet(ResolveRoomIdMixin, RestServlet):
         # Figure out which local users currently have power in the room, if any.
         room_state = await self.state_handler.get_current_state(room_id)
         if not room_state:
-            raise SynapseError(HTTPStatus.BAD_REQUEST, "Server not in room")
+            raise SynapseError(400, "Server not in room")
 
         create_event = room_state[(EventTypes.Create, "")]
         power_levels = room_state.get((EventTypes.PowerLevels, ""))
@@ -582,9 +582,7 @@ class MakeRoomAdminRestServlet(ResolveRoomIdMixin, RestServlet):
             admin_users.sort(key=lambda user: user_power[user])
 
             if not admin_users:
-                raise SynapseError(
-                    HTTPStatus.BAD_REQUEST, "No local admin user in room"
-                )
+                raise SynapseError(400, "No local admin user in room")
 
             admin_user_id = None
 
@@ -601,7 +599,7 @@ class MakeRoomAdminRestServlet(ResolveRoomIdMixin, RestServlet):
 
             if not admin_user_id:
                 raise SynapseError(
-                    HTTPStatus.BAD_REQUEST,
+                    400,
                     "No local admin user in room",
                 )
 
@@ -612,7 +610,7 @@ class MakeRoomAdminRestServlet(ResolveRoomIdMixin, RestServlet):
             admin_user_id = create_event.sender
             if not self.is_mine_id(admin_user_id):
                 raise SynapseError(
-                    HTTPStatus.BAD_REQUEST,
+                    400,
                     "No local admin user in room",
                 )
 
@@ -641,8 +639,7 @@ class MakeRoomAdminRestServlet(ResolveRoomIdMixin, RestServlet):
         except AuthError:
             # The admin user we found turned out not to have enough power.
             raise SynapseError(
-                HTTPStatus.BAD_REQUEST,
-                "No local admin user in room with power to update power levels.",
+                400, "No local admin user in room with power to update power levels."
             )
 
         # Now we check if the user we're granting admin rights to is already in
@@ -656,7 +653,7 @@ class MakeRoomAdminRestServlet(ResolveRoomIdMixin, RestServlet):
             )
 
         if is_joined:
-            return HTTPStatus.OK, {}
+            return 200, {}
 
         join_rules = room_state.get((EventTypes.JoinRules, ""))
         is_public = False
@@ -664,7 +661,7 @@ class MakeRoomAdminRestServlet(ResolveRoomIdMixin, RestServlet):
             is_public = join_rules.content.get("join_rule") == JoinRules.PUBLIC
 
         if is_public:
-            return HTTPStatus.OK, {}
+            return 200, {}
 
         await self.room_member_handler.update_membership(
             fake_requester,
@@ -673,7 +670,7 @@ class MakeRoomAdminRestServlet(ResolveRoomIdMixin, RestServlet):
             action=Membership.INVITE,
         )
 
-        return HTTPStatus.OK, {}
+        return 200, {}
 
 
 class ForwardExtremitiesRestServlet(ResolveRoomIdMixin, RestServlet):
@@ -705,7 +702,7 @@ class ForwardExtremitiesRestServlet(ResolveRoomIdMixin, RestServlet):
         room_id, _ = await self.resolve_room_id(room_identifier)
 
         deleted_count = await self.store.delete_forward_extremities_for_room(room_id)
-        return HTTPStatus.OK, {"deleted": deleted_count}
+        return 200, {"deleted": deleted_count}
 
     async def on_GET(
         self, request: SynapseRequest, room_identifier: str
@@ -716,7 +713,7 @@ class ForwardExtremitiesRestServlet(ResolveRoomIdMixin, RestServlet):
         room_id, _ = await self.resolve_room_id(room_identifier)
 
         extremities = await self.store.get_forward_extremities_for_room(room_id)
-        return HTTPStatus.OK, {"count": len(extremities), "results": extremities}
+        return 200, {"count": len(extremities), "results": extremities}
 
 
 class RoomEventContextServlet(RestServlet):
@@ -765,9 +762,7 @@ class RoomEventContextServlet(RestServlet):
         )
 
         if not results:
-            raise SynapseError(
-                HTTPStatus.NOT_FOUND, "Event not found.", errcode=Codes.NOT_FOUND
-            )
+            raise SynapseError(404, "Event not found.", errcode=Codes.NOT_FOUND)
 
         time_now = self.clock.time_msec()
         results["events_before"] = await self._event_serializer.serialize_events(
@@ -780,10 +775,13 @@ class RoomEventContextServlet(RestServlet):
             results["events_after"], time_now
         )
         results["state"] = await self._event_serializer.serialize_events(
-            results["state"], time_now
+            results["state"],
+            time_now,
+            # No need to bundle aggregations for state events
+            bundle_relations=False,
         )
 
-        return HTTPStatus.OK, results
+        return 200, results
 
 
 class BlockRoomRestServlet(RestServlet):
diff --git a/synapse/rest/admin/server_notice_servlet.py b/synapse/rest/admin/server_notice_servlet.py
index b295fb078b..19f84f33f2 100644
--- a/synapse/rest/admin/server_notice_servlet.py
+++ b/synapse/rest/admin/server_notice_servlet.py
@@ -11,7 +11,6 @@
 # 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 http import HTTPStatus
 from typing import TYPE_CHECKING, Awaitable, Optional, Tuple
 
 from synapse.api.constants import EventTypes
@@ -83,15 +82,11 @@ class SendServerNoticeServlet(RestServlet):
         # but worker processes still need to initialise SendServerNoticeServlet (as it is part of the
         # admin api).
         if not self.server_notices_manager.is_enabled():
-            raise SynapseError(
-                HTTPStatus.BAD_REQUEST, "Server notices are not enabled on this server"
-            )
+            raise SynapseError(400, "Server notices are not enabled on this server")
 
         target_user = UserID.from_string(body["user_id"])
         if not self.hs.is_mine(target_user):
-            raise SynapseError(
-                HTTPStatus.BAD_REQUEST, "Server notices can only be sent to local users"
-            )
+            raise SynapseError(400, "Server notices can only be sent to local users")
 
         if not await self.admin_handler.get_user(target_user):
             raise NotFoundError("User not found")
@@ -104,7 +99,7 @@ class SendServerNoticeServlet(RestServlet):
             txn_id=txn_id,
         )
 
-        return HTTPStatus.OK, {"event_id": event.event_id}
+        return 200, {"event_id": event.event_id}
 
     def on_PUT(
         self, request: SynapseRequest, txn_id: str
diff --git a/synapse/rest/admin/statistics.py b/synapse/rest/admin/statistics.py
index ca41fd45f2..948de94ccd 100644
--- a/synapse/rest/admin/statistics.py
+++ b/synapse/rest/admin/statistics.py
@@ -13,7 +13,6 @@
 # limitations under the License.
 
 import logging
-from http import HTTPStatus
 from typing import TYPE_CHECKING, Tuple
 
 from synapse.api.errors import Codes, SynapseError
@@ -54,7 +53,7 @@ class UserMediaStatisticsRestServlet(RestServlet):
             UserSortOrder.DISPLAYNAME.value,
         ):
             raise SynapseError(
-                HTTPStatus.BAD_REQUEST,
+                400,
                 "Unknown value for order_by: %s" % (order_by,),
                 errcode=Codes.INVALID_PARAM,
             )
@@ -62,7 +61,7 @@ class UserMediaStatisticsRestServlet(RestServlet):
         start = parse_integer(request, "from", default=0)
         if start < 0:
             raise SynapseError(
-                HTTPStatus.BAD_REQUEST,
+                400,
                 "Query parameter from must be a string representing a positive integer.",
                 errcode=Codes.INVALID_PARAM,
             )
@@ -70,7 +69,7 @@ class UserMediaStatisticsRestServlet(RestServlet):
         limit = parse_integer(request, "limit", default=100)
         if limit < 0:
             raise SynapseError(
-                HTTPStatus.BAD_REQUEST,
+                400,
                 "Query parameter limit must be a string representing a positive integer.",
                 errcode=Codes.INVALID_PARAM,
             )
@@ -78,7 +77,7 @@ class UserMediaStatisticsRestServlet(RestServlet):
         from_ts = parse_integer(request, "from_ts", default=0)
         if from_ts < 0:
             raise SynapseError(
-                HTTPStatus.BAD_REQUEST,
+                400,
                 "Query parameter from_ts must be a string representing a positive integer.",
                 errcode=Codes.INVALID_PARAM,
             )
@@ -87,13 +86,13 @@ class UserMediaStatisticsRestServlet(RestServlet):
         if until_ts is not None:
             if until_ts < 0:
                 raise SynapseError(
-                    HTTPStatus.BAD_REQUEST,
+                    400,
                     "Query parameter until_ts must be a string representing a positive integer.",
                     errcode=Codes.INVALID_PARAM,
                 )
             if until_ts <= from_ts:
                 raise SynapseError(
-                    HTTPStatus.BAD_REQUEST,
+                    400,
                     "Query parameter until_ts must be greater than from_ts.",
                     errcode=Codes.INVALID_PARAM,
                 )
@@ -101,7 +100,7 @@ class UserMediaStatisticsRestServlet(RestServlet):
         search_term = parse_string(request, "search_term")
         if search_term == "":
             raise SynapseError(
-                HTTPStatus.BAD_REQUEST,
+                400,
                 "Query parameter search_term cannot be an empty string.",
                 errcode=Codes.INVALID_PARAM,
             )
@@ -109,9 +108,7 @@ class UserMediaStatisticsRestServlet(RestServlet):
         direction = parse_string(request, "dir", default="f")
         if direction not in ("f", "b"):
             raise SynapseError(
-                HTTPStatus.BAD_REQUEST,
-                "Unknown direction: %s" % (direction,),
-                errcode=Codes.INVALID_PARAM,
+                400, "Unknown direction: %s" % (direction,), errcode=Codes.INVALID_PARAM
             )
 
         users_media, total = await self.store.get_users_media_usage_paginate(
@@ -121,4 +118,4 @@ class UserMediaStatisticsRestServlet(RestServlet):
         if (start + limit) < total:
             ret["next_token"] = start + len(users_media)
 
-        return HTTPStatus.OK, ret
+        return 200, ret
diff --git a/synapse/rest/admin/users.py b/synapse/rest/admin/users.py
index 2a60b602b1..ccd9a2a175 100644
--- a/synapse/rest/admin/users.py
+++ b/synapse/rest/admin/users.py
@@ -79,14 +79,14 @@ class UsersRestServletV2(RestServlet):
 
         if start < 0:
             raise SynapseError(
-                HTTPStatus.BAD_REQUEST,
+                400,
                 "Query parameter from must be a string representing a positive integer.",
                 errcode=Codes.INVALID_PARAM,
             )
 
         if limit < 0:
             raise SynapseError(
-                HTTPStatus.BAD_REQUEST,
+                400,
                 "Query parameter limit must be a string representing a positive integer.",
                 errcode=Codes.INVALID_PARAM,
             )
@@ -122,7 +122,7 @@ class UsersRestServletV2(RestServlet):
         if (start + limit) < total:
             ret["next_token"] = str(start + len(users))
 
-        return HTTPStatus.OK, ret
+        return 200, ret
 
 
 class UserRestServletV2(RestServlet):
@@ -172,14 +172,14 @@ class UserRestServletV2(RestServlet):
 
         target_user = UserID.from_string(user_id)
         if not self.hs.is_mine(target_user):
-            raise SynapseError(HTTPStatus.BAD_REQUEST, "Can only look up local users")
+            raise SynapseError(400, "Can only look up local users")
 
         ret = await self.admin_handler.get_user(target_user)
 
         if not ret:
             raise NotFoundError("User not found")
 
-        return HTTPStatus.OK, ret
+        return 200, ret
 
     async def on_PUT(
         self, request: SynapseRequest, user_id: str
@@ -191,10 +191,7 @@ class UserRestServletV2(RestServlet):
         body = parse_json_object_from_request(request)
 
         if not self.hs.is_mine(target_user):
-            raise SynapseError(
-                HTTPStatus.BAD_REQUEST,
-                "This endpoint can only be used with local users",
-            )
+            raise SynapseError(400, "This endpoint can only be used with local users")
 
         user = await self.admin_handler.get_user(target_user)
         user_id = target_user.to_string()
@@ -213,7 +210,7 @@ class UserRestServletV2(RestServlet):
 
         user_type = body.get("user_type", None)
         if user_type is not None and user_type not in UserTypes.ALL_USER_TYPES:
-            raise SynapseError(HTTPStatus.BAD_REQUEST, "Invalid user type")
+            raise SynapseError(400, "Invalid user type")
 
         set_admin_to = body.get("admin", False)
         if not isinstance(set_admin_to, bool):
@@ -226,13 +223,11 @@ class UserRestServletV2(RestServlet):
         password = body.get("password", None)
         if password is not None:
             if not isinstance(password, str) or len(password) > 512:
-                raise SynapseError(HTTPStatus.BAD_REQUEST, "Invalid password")
+                raise SynapseError(400, "Invalid password")
 
         deactivate = body.get("deactivated", False)
         if not isinstance(deactivate, bool):
-            raise SynapseError(
-                HTTPStatus.BAD_REQUEST, "'deactivated' parameter is not of type boolean"
-            )
+            raise SynapseError(400, "'deactivated' parameter is not of type boolean")
 
         # convert List[Dict[str, str]] into List[Tuple[str, str]]
         if external_ids is not None:
@@ -287,9 +282,7 @@ class UserRestServletV2(RestServlet):
                         user_id,
                     )
                 except ExternalIDReuseException:
-                    raise SynapseError(
-                        HTTPStatus.CONFLICT, "External id is already in use."
-                    )
+                    raise SynapseError(409, "External id is already in use.")
 
             if "avatar_url" in body and isinstance(body["avatar_url"], str):
                 await self.profile_handler.set_avatar_url(
@@ -300,9 +293,7 @@ class UserRestServletV2(RestServlet):
                 if set_admin_to != user["admin"]:
                     auth_user = requester.user
                     if target_user == auth_user and not set_admin_to:
-                        raise SynapseError(
-                            HTTPStatus.BAD_REQUEST, "You may not demote yourself."
-                        )
+                        raise SynapseError(400, "You may not demote yourself.")
 
                     await self.store.set_server_admin(target_user, set_admin_to)
 
@@ -328,8 +319,7 @@ class UserRestServletV2(RestServlet):
                         and self.auth_handler.can_change_password()
                     ):
                         raise SynapseError(
-                            HTTPStatus.BAD_REQUEST,
-                            "Must provide a password to re-activate an account.",
+                            400, "Must provide a password to re-activate an account."
                         )
 
                     await self.deactivate_account_handler.activate_account(
@@ -342,7 +332,7 @@ class UserRestServletV2(RestServlet):
             user = await self.admin_handler.get_user(target_user)
             assert user is not None
 
-            return HTTPStatus.OK, user
+            return 200, user
 
         else:  # create user
             displayname = body.get("displayname", None)
@@ -391,9 +381,7 @@ class UserRestServletV2(RestServlet):
                             user_id,
                         )
                 except ExternalIDReuseException:
-                    raise SynapseError(
-                        HTTPStatus.CONFLICT, "External id is already in use."
-                    )
+                    raise SynapseError(409, "External id is already in use.")
 
             if "avatar_url" in body and isinstance(body["avatar_url"], str):
                 await self.profile_handler.set_avatar_url(
@@ -441,61 +429,51 @@ class UserRegisterServlet(RestServlet):
 
         nonce = secrets.token_hex(64)
         self.nonces[nonce] = int(self.reactor.seconds())
-        return HTTPStatus.OK, {"nonce": nonce}
+        return 200, {"nonce": nonce}
 
     async def on_POST(self, request: SynapseRequest) -> Tuple[int, JsonDict]:
         self._clear_old_nonces()
 
         if not self.hs.config.registration.registration_shared_secret:
-            raise SynapseError(
-                HTTPStatus.BAD_REQUEST, "Shared secret registration is not enabled"
-            )
+            raise SynapseError(400, "Shared secret registration is not enabled")
 
         body = parse_json_object_from_request(request)
 
         if "nonce" not in body:
-            raise SynapseError(
-                HTTPStatus.BAD_REQUEST,
-                "nonce must be specified",
-                errcode=Codes.BAD_JSON,
-            )
+            raise SynapseError(400, "nonce must be specified", errcode=Codes.BAD_JSON)
 
         nonce = body["nonce"]
 
         if nonce not in self.nonces:
-            raise SynapseError(HTTPStatus.BAD_REQUEST, "unrecognised nonce")
+            raise SynapseError(400, "unrecognised nonce")
 
         # Delete the nonce, so it can't be reused, even if it's invalid
         del self.nonces[nonce]
 
         if "username" not in body:
             raise SynapseError(
-                HTTPStatus.BAD_REQUEST,
-                "username must be specified",
-                errcode=Codes.BAD_JSON,
+                400, "username must be specified", errcode=Codes.BAD_JSON
             )
         else:
             if not isinstance(body["username"], str) or len(body["username"]) > 512:
-                raise SynapseError(HTTPStatus.BAD_REQUEST, "Invalid username")
+                raise SynapseError(400, "Invalid username")
 
             username = body["username"].encode("utf-8")
             if b"\x00" in username:
-                raise SynapseError(HTTPStatus.BAD_REQUEST, "Invalid username")
+                raise SynapseError(400, "Invalid username")
 
         if "password" not in body:
             raise SynapseError(
-                HTTPStatus.BAD_REQUEST,
-                "password must be specified",
-                errcode=Codes.BAD_JSON,
+                400, "password must be specified", errcode=Codes.BAD_JSON
             )
         else:
             password = body["password"]
             if not isinstance(password, str) or len(password) > 512:
-                raise SynapseError(HTTPStatus.BAD_REQUEST, "Invalid password")
+                raise SynapseError(400, "Invalid password")
 
             password_bytes = password.encode("utf-8")
             if b"\x00" in password_bytes:
-                raise SynapseError(HTTPStatus.BAD_REQUEST, "Invalid password")
+                raise SynapseError(400, "Invalid password")
 
             password_hash = await self.auth_handler.hash(password)
 
@@ -504,12 +482,10 @@ class UserRegisterServlet(RestServlet):
         displayname = body.get("displayname", None)
 
         if user_type is not None and user_type not in UserTypes.ALL_USER_TYPES:
-            raise SynapseError(HTTPStatus.BAD_REQUEST, "Invalid user type")
+            raise SynapseError(400, "Invalid user type")
 
         if "mac" not in body:
-            raise SynapseError(
-                HTTPStatus.BAD_REQUEST, "mac must be specified", errcode=Codes.BAD_JSON
-            )
+            raise SynapseError(400, "mac must be specified", errcode=Codes.BAD_JSON)
 
         got_mac = body["mac"]
 
@@ -531,7 +507,7 @@ class UserRegisterServlet(RestServlet):
         want_mac = want_mac_builder.hexdigest()
 
         if not hmac.compare_digest(want_mac.encode("ascii"), got_mac.encode("ascii")):
-            raise SynapseError(HTTPStatus.FORBIDDEN, "HMAC incorrect")
+            raise SynapseError(403, "HMAC incorrect")
 
         # Reuse the parts of RegisterRestServlet to reduce code duplication
         from synapse.rest.client.register import RegisterRestServlet
@@ -548,7 +524,7 @@ class UserRegisterServlet(RestServlet):
         )
 
         result = await register._create_registration_details(user_id, body)
-        return HTTPStatus.OK, result
+        return 200, result
 
 
 class WhoisRestServlet(RestServlet):
@@ -576,11 +552,11 @@ class WhoisRestServlet(RestServlet):
             await assert_user_is_admin(self.auth, auth_user)
 
         if not self.hs.is_mine(target_user):
-            raise SynapseError(HTTPStatus.BAD_REQUEST, "Can only whois a local user")
+            raise SynapseError(400, "Can only whois a local user")
 
         ret = await self.admin_handler.get_whois(target_user)
 
-        return HTTPStatus.OK, ret
+        return 200, ret
 
 
 class DeactivateAccountRestServlet(RestServlet):
@@ -599,9 +575,7 @@ class DeactivateAccountRestServlet(RestServlet):
         await assert_user_is_admin(self.auth, requester.user)
 
         if not self.is_mine(UserID.from_string(target_user_id)):
-            raise SynapseError(
-                HTTPStatus.BAD_REQUEST, "Can only deactivate local users"
-            )
+            raise SynapseError(400, "Can only deactivate local users")
 
         if not await self.store.get_user_by_id(target_user_id):
             raise NotFoundError("User not found")
@@ -623,7 +597,7 @@ class DeactivateAccountRestServlet(RestServlet):
         else:
             id_server_unbind_result = "no-support"
 
-        return HTTPStatus.OK, {"id_server_unbind_result": id_server_unbind_result}
+        return 200, {"id_server_unbind_result": id_server_unbind_result}
 
 
 class AccountValidityRenewServlet(RestServlet):
@@ -646,7 +620,7 @@ class AccountValidityRenewServlet(RestServlet):
 
             if "user_id" not in body:
                 raise SynapseError(
-                    HTTPStatus.BAD_REQUEST,
+                    400,
                     "Missing property 'user_id' in the request body",
                 )
 
@@ -657,7 +631,7 @@ class AccountValidityRenewServlet(RestServlet):
             )
 
         res = {"expiration_ts": expiration_ts}
-        return HTTPStatus.OK, res
+        return 200, res
 
 
 class ResetPasswordRestServlet(RestServlet):
@@ -704,7 +678,7 @@ class ResetPasswordRestServlet(RestServlet):
         await self._set_password_handler.set_password(
             target_user_id, new_password_hash, logout_devices, requester
         )
-        return HTTPStatus.OK, {}
+        return 200, {}
 
 
 class SearchUsersRestServlet(RestServlet):
@@ -738,16 +712,16 @@ class SearchUsersRestServlet(RestServlet):
 
         # To allow all users to get the users list
         # if not is_admin and target_user != auth_user:
-        #     raise AuthError(HTTPStatus.FORBIDDEN, "You are not a server admin")
+        #     raise AuthError(403, "You are not a server admin")
 
         if not self.hs.is_mine(target_user):
-            raise SynapseError(HTTPStatus.BAD_REQUEST, "Can only users a local user")
+            raise SynapseError(400, "Can only users a local user")
 
         term = parse_string(request, "term", required=True)
         logger.info("term: %s ", term)
 
         ret = await self.store.search_users(term)
-        return HTTPStatus.OK, ret
+        return 200, ret
 
 
 class UserAdminServlet(RestServlet):
@@ -791,14 +765,11 @@ class UserAdminServlet(RestServlet):
         target_user = UserID.from_string(user_id)
 
         if not self.hs.is_mine(target_user):
-            raise SynapseError(
-                HTTPStatus.BAD_REQUEST,
-                "Only local users can be admins of this homeserver",
-            )
+            raise SynapseError(400, "Only local users can be admins of this homeserver")
 
         is_admin = await self.store.is_server_admin(target_user)
 
-        return HTTPStatus.OK, {"admin": is_admin}
+        return 200, {"admin": is_admin}
 
     async def on_PUT(
         self, request: SynapseRequest, user_id: str
@@ -814,19 +785,16 @@ class UserAdminServlet(RestServlet):
         assert_params_in_dict(body, ["admin"])
 
         if not self.hs.is_mine(target_user):
-            raise SynapseError(
-                HTTPStatus.BAD_REQUEST,
-                "Only local users can be admins of this homeserver",
-            )
+            raise SynapseError(400, "Only local users can be admins of this homeserver")
 
         set_admin_to = bool(body["admin"])
 
         if target_user == auth_user and not set_admin_to:
-            raise SynapseError(HTTPStatus.BAD_REQUEST, "You may not demote yourself.")
+            raise SynapseError(400, "You may not demote yourself.")
 
         await self.store.set_server_admin(target_user, set_admin_to)
 
-        return HTTPStatus.OK, {}
+        return 200, {}
 
 
 class UserMembershipRestServlet(RestServlet):
@@ -848,7 +816,7 @@ class UserMembershipRestServlet(RestServlet):
 
         room_ids = await self.store.get_rooms_for_user(user_id)
         ret = {"joined_rooms": list(room_ids), "total": len(room_ids)}
-        return HTTPStatus.OK, ret
+        return 200, ret
 
 
 class PushersRestServlet(RestServlet):
@@ -877,7 +845,7 @@ class PushersRestServlet(RestServlet):
         await assert_requester_is_admin(self.auth, request)
 
         if not self.is_mine(UserID.from_string(user_id)):
-            raise SynapseError(HTTPStatus.BAD_REQUEST, "Can only look up local users")
+            raise SynapseError(400, "Can only look up local users")
 
         if not await self.store.get_user_by_id(user_id):
             raise NotFoundError("User not found")
@@ -886,10 +854,7 @@ class PushersRestServlet(RestServlet):
 
         filtered_pushers = [p.as_dict() for p in pushers]
 
-        return HTTPStatus.OK, {
-            "pushers": filtered_pushers,
-            "total": len(filtered_pushers),
-        }
+        return 200, {"pushers": filtered_pushers, "total": len(filtered_pushers)}
 
 
 class UserTokenRestServlet(RestServlet):
@@ -922,22 +887,16 @@ class UserTokenRestServlet(RestServlet):
         auth_user = requester.user
 
         if not self.hs.is_mine_id(user_id):
-            raise SynapseError(
-                HTTPStatus.BAD_REQUEST, "Only local users can be logged in as"
-            )
+            raise SynapseError(400, "Only local users can be logged in as")
 
         body = parse_json_object_from_request(request, allow_empty_body=True)
 
         valid_until_ms = body.get("valid_until_ms")
         if valid_until_ms and not isinstance(valid_until_ms, int):
-            raise SynapseError(
-                HTTPStatus.BAD_REQUEST, "'valid_until_ms' parameter must be an int"
-            )
+            raise SynapseError(400, "'valid_until_ms' parameter must be an int")
 
         if auth_user.to_string() == user_id:
-            raise SynapseError(
-                HTTPStatus.BAD_REQUEST, "Cannot use admin API to login as self"
-            )
+            raise SynapseError(400, "Cannot use admin API to login as self")
 
         token = await self.auth_handler.create_access_token_for_user_id(
             user_id=auth_user.to_string(),
@@ -946,7 +905,7 @@ class UserTokenRestServlet(RestServlet):
             puppets_user_id=user_id,
         )
 
-        return HTTPStatus.OK, {"access_token": token}
+        return 200, {"access_token": token}
 
 
 class ShadowBanRestServlet(RestServlet):
@@ -988,13 +947,11 @@ class ShadowBanRestServlet(RestServlet):
         await assert_requester_is_admin(self.auth, request)
 
         if not self.hs.is_mine_id(user_id):
-            raise SynapseError(
-                HTTPStatus.BAD_REQUEST, "Only local users can be shadow-banned"
-            )
+            raise SynapseError(400, "Only local users can be shadow-banned")
 
         await self.store.set_shadow_banned(UserID.from_string(user_id), True)
 
-        return HTTPStatus.OK, {}
+        return 200, {}
 
     async def on_DELETE(
         self, request: SynapseRequest, user_id: str
@@ -1002,13 +959,11 @@ class ShadowBanRestServlet(RestServlet):
         await assert_requester_is_admin(self.auth, request)
 
         if not self.hs.is_mine_id(user_id):
-            raise SynapseError(
-                HTTPStatus.BAD_REQUEST, "Only local users can be shadow-banned"
-            )
+            raise SynapseError(400, "Only local users can be shadow-banned")
 
         await self.store.set_shadow_banned(UserID.from_string(user_id), False)
 
-        return HTTPStatus.OK, {}
+        return 200, {}
 
 
 class RateLimitRestServlet(RestServlet):
@@ -1040,7 +995,7 @@ class RateLimitRestServlet(RestServlet):
         await assert_requester_is_admin(self.auth, request)
 
         if not self.hs.is_mine_id(user_id):
-            raise SynapseError(HTTPStatus.BAD_REQUEST, "Can only look up local users")
+            raise SynapseError(400, "Can only look up local users")
 
         if not await self.store.get_user_by_id(user_id):
             raise NotFoundError("User not found")
@@ -1061,7 +1016,7 @@ class RateLimitRestServlet(RestServlet):
         else:
             ret = {}
 
-        return HTTPStatus.OK, ret
+        return 200, ret
 
     async def on_POST(
         self, request: SynapseRequest, user_id: str
@@ -1069,9 +1024,7 @@ class RateLimitRestServlet(RestServlet):
         await assert_requester_is_admin(self.auth, request)
 
         if not self.hs.is_mine_id(user_id):
-            raise SynapseError(
-                HTTPStatus.BAD_REQUEST, "Only local users can be ratelimited"
-            )
+            raise SynapseError(400, "Only local users can be ratelimited")
 
         if not await self.store.get_user_by_id(user_id):
             raise NotFoundError("User not found")
@@ -1083,14 +1036,14 @@ class RateLimitRestServlet(RestServlet):
 
         if not isinstance(messages_per_second, int) or messages_per_second < 0:
             raise SynapseError(
-                HTTPStatus.BAD_REQUEST,
+                400,
                 "%r parameter must be a positive int" % (messages_per_second,),
                 errcode=Codes.INVALID_PARAM,
             )
 
         if not isinstance(burst_count, int) or burst_count < 0:
             raise SynapseError(
-                HTTPStatus.BAD_REQUEST,
+                400,
                 "%r parameter must be a positive int" % (burst_count,),
                 errcode=Codes.INVALID_PARAM,
             )
@@ -1106,7 +1059,7 @@ class RateLimitRestServlet(RestServlet):
             "burst_count": ratelimit.burst_count,
         }
 
-        return HTTPStatus.OK, ret
+        return 200, ret
 
     async def on_DELETE(
         self, request: SynapseRequest, user_id: str
@@ -1114,13 +1067,11 @@ class RateLimitRestServlet(RestServlet):
         await assert_requester_is_admin(self.auth, request)
 
         if not self.hs.is_mine_id(user_id):
-            raise SynapseError(
-                HTTPStatus.BAD_REQUEST, "Only local users can be ratelimited"
-            )
+            raise SynapseError(400, "Only local users can be ratelimited")
 
         if not await self.store.get_user_by_id(user_id):
             raise NotFoundError("User not found")
 
         await self.store.delete_ratelimit_for_user(user_id)
 
-        return HTTPStatus.OK, {}
+        return 200, {}