8 files changed, 164 insertions, 24 deletions
diff --git a/docs/SUMMARY.md b/docs/SUMMARY.md
index 21f80efc99..6aa48e1919 100644
--- a/docs/SUMMARY.md
+++ b/docs/SUMMARY.md
@@ -45,6 +45,7 @@
         - [Account validity callbacks](modules/account_validity_callbacks.md)
         - [Password auth provider callbacks](modules/password_auth_provider_callbacks.md)
         - [Background update controller callbacks](modules/background_update_controller_callbacks.md)
+        - [Account data callbacks](modules/account_data_callbacks.md)
         - [Porting a legacy module to the new interface](modules/porting_legacy_module.md)
     - [Workers](workers.md)
       - [Using `synctl` with Workers](synctl_workers.md)
diff --git a/docs/development/contributing_guide.md b/docs/development/contributing_guide.md
index 071202e196..0d9cf60196 100644
--- a/docs/development/contributing_guide.md
+++ b/docs/development/contributing_guide.md
@@ -206,9 +206,10 @@ To do so, [configure Postgres](../postgres.md) and run `trial` with the
 following environment variables matching your configuration:
 
 - `SYNAPSE_POSTGRES` to anything nonempty
-- `SYNAPSE_POSTGRES_HOST`
-- `SYNAPSE_POSTGRES_USER`
-- `SYNAPSE_POSTGRES_PASSWORD`
+- `SYNAPSE_POSTGRES_HOST` (optional if it's the default: UNIX socket)
+- `SYNAPSE_POSTGRES_PORT` (optional if it's the default: 5432)
+- `SYNAPSE_POSTGRES_USER` (optional if using a UNIX socket)
+- `SYNAPSE_POSTGRES_PASSWORD` (optional if using a UNIX socket)
 
 For example:
 
@@ -220,26 +221,12 @@ export SYNAPSE_POSTGRES_PASSWORD=mydevenvpassword
 trial
 ```
 
-#### Prebuilt container
+You don't need to specify the host, user, port or password if your Postgres
+server is set to authenticate you over the UNIX socket (i.e. if the `psql` command
+works without further arguments).
 
-Since configuring PostgreSQL can be fiddly, we can make use of a pre-made
-Docker container to set up PostgreSQL and run our tests for us. To do so, run
+Your Postgres account needs to be able to create databases.
 
-```shell
-scripts-dev/test_postgresql.sh
-```
-
-Any extra arguments to the script will be passed to `tox` and then to `trial`,
-so we can run a specific test in this container with e.g.
-
-```shell
-scripts-dev/test_postgresql.sh tests.replication.test_sharded_event_persister.EventPersisterShardTestCase
-```
-
-The container creates a folder in your Synapse checkout called
-`.tox-pg-container` and uses this as a tox environment. The output of any
-`trial` runs goes into `_trial_temp` in your synapse source directory — the same
-as running `trial` directly on your host machine.
 
 ## Run the integration tests ([Sytest](https://github.com/matrix-org/sytest)).
 
@@ -254,8 +241,14 @@ configuration:
 ```sh
 $ docker run --rm -it -v /path/where/you/have/cloned/the/repository\:/src:ro -v /path/to/where/you/want/logs\:/logs matrixdotorg/sytest-synapse:buster
 ```
+(Note that the paths must be full paths! You could also write `$(realpath relative/path)` if needed.)
+
+This configuration should generally cover your needs.
+
+- To run with Postgres, supply the `-e POSTGRES=1 -e MULTI_POSTGRES=1` environment flags.
+- To run with Synapse in worker mode, supply the `-e WORKERS=1 -e REDIS=1` environment flags (in addition to the Postgres flags).
 
-This configuration should generally cover  your needs. For more details about other configurations, see [documentation in the SyTest repo](https://github.com/matrix-org/sytest/blob/develop/docker/README.md).
+For more details about other configurations, see the [Docker-specific documentation in the SyTest repo](https://github.com/matrix-org/sytest/blob/develop/docker/README.md).
 
 
 ## Run the integration tests ([Complement](https://github.com/matrix-org/complement)).
diff --git a/docs/modules/account_data_callbacks.md b/docs/modules/account_data_callbacks.md
new file mode 100644
index 0000000000..25de911627
--- /dev/null
+++ b/docs/modules/account_data_callbacks.md
@@ -0,0 +1,106 @@
+# Account data callbacks
+
+Account data callbacks allow module developers to react to changes of the account data
+of local users. Account data callbacks can be registered using the module API's
+`register_account_data_callbacks` method.
+
+## Callbacks
+
+The available account data callbacks are:
+
+### `on_account_data_updated`
+
+_First introduced in Synapse v1.57.0_
+
+```python
+async def on_account_data_updated(
+    user_id: str,
+    room_id: Optional[str],
+    account_data_type: str,
+    content: "synapse.module_api.JsonDict",
+) -> None:
+```
+
+Called after user's account data has been updated. The module is given the
+Matrix ID of the user whose account data is changing, the room ID the data is associated
+with, the type associated with the change, as well as the new content. If the account
+data is not associated with a specific room, then the room ID is `None`.
+
+This callback is triggered when new account data is added or when the data associated with
+a given type (and optionally room) changes. This includes deletion, since in Matrix,
+deleting account data consists of replacing the data associated with a given type
+(and optionally room) with an empty dictionary (`{}`).
+
+Note that this doesn't trigger when changing the tags associated with a room, as these are
+processed separately by Synapse.
+
+If multiple modules implement this callback, Synapse runs them all in order.
+
+## Example
+
+The example below is a module that implements the `on_account_data_updated` callback, and
+sends an event to an audit room when a user changes their account data.
+
+```python
+import json
+import attr
+from typing import Any, Dict, Optional
+
+from synapse.module_api import JsonDict, ModuleApi
+from synapse.module_api.errors import ConfigError
+
+
+@attr.s(auto_attribs=True)
+class CustomAccountDataConfig:
+    audit_room: str
+    sender: str
+
+
+class CustomAccountDataModule:
+    def __init__(self, config: CustomAccountDataConfig, api: ModuleApi):
+        self.api = api
+        self.config = config
+
+        self.api.register_account_data_callbacks(
+            on_account_data_updated=self.log_new_account_data,
+        )
+
+    @staticmethod
+    def parse_config(config: Dict[str, Any]) -> CustomAccountDataConfig:
+        def check_in_config(param: str):
+            if param not in config:
+                raise ConfigError(f"'{param}' is required")
+
+        check_in_config("audit_room")
+        check_in_config("sender")
+
+        return CustomAccountDataConfig(
+            audit_room=config["audit_room"],
+            sender=config["sender"],
+        )
+
+    async def log_new_account_data(
+        self,
+        user_id: str,
+        room_id: Optional[str],
+        account_data_type: str,
+        content: JsonDict,
+    ) -> None:
+        content_raw = json.dumps(content)
+        msg_content = f"{user_id} has changed their account data for type {account_data_type} to: {content_raw}"
+
+        if room_id is not None:
+            msg_content += f" (in room {room_id})"
+
+        await self.api.create_and_send_event_into_room(
+            {
+                "room_id": self.config.audit_room,
+                "sender": self.config.sender,
+                "type": "m.room.message",
+                "content": {
+                    "msgtype": "m.text",
+                    "body": msg_content
+                }
+            }
+        )
+```
diff --git a/docs/modules/third_party_rules_callbacks.md b/docs/modules/third_party_rules_callbacks.md
index 1d3c39967f..e1a5b6524f 100644
--- a/docs/modules/third_party_rules_callbacks.md
+++ b/docs/modules/third_party_rules_callbacks.md
@@ -247,6 +247,24 @@ admin API.
 
 If multiple modules implement this callback, Synapse runs them all in order.
 
+### `on_threepid_bind`
+
+_First introduced in Synapse v1.56.0_
+
+```python
+async def on_threepid_bind(user_id: str, medium: str, address: str) -> None:
+```
+
+Called after creating an association between a local user and a third-party identifier
+(email address, phone number). The module is given the Matrix ID of the user the
+association is for, as well as the medium (`email` or `msisdn`) and address of the
+third-party identifier.
+
+Note that this callback is _not_ called after a successful association on an _identity
+server_.
+
+If multiple modules implement this callback, Synapse runs them all in order.
+
 ## Example
 
 The example below is a module that implements the third-party rules callback
diff --git a/docs/modules/writing_a_module.md b/docs/modules/writing_a_module.md
index e7c0ffad58..e6303b739e 100644
--- a/docs/modules/writing_a_module.md
+++ b/docs/modules/writing_a_module.md
@@ -33,7 +33,7 @@ A module can implement the following static method:
 
 ```python
 @staticmethod
-def parse_config(config: dict) -> dict
+def parse_config(config: dict) -> Any
 ```
 
 This method is given a dictionary resulting from parsing the YAML configuration for the
diff --git a/docs/sample_config.yaml b/docs/sample_config.yaml
index a21b48ab2e..b8d8c0dbf0 100644
--- a/docs/sample_config.yaml
+++ b/docs/sample_config.yaml
@@ -539,6 +539,15 @@ templates:
   #
   #custom_template_directory: /path/to/custom/templates/
 
+# List of rooms to exclude from sync responses. This is useful for server
+# administrators wishing to group users into a room without these users being able
+# to see it from their client.
+#
+# By default, no room is excluded.
+#
+#exclude_rooms_from_sync:
+#    - !foo:example.com
+
 
 # Message retention policy at the server level.
 #
diff --git a/docs/upgrade.md b/docs/upgrade.md
index 10d81b949c..de3444930e 100644
--- a/docs/upgrade.md
+++ b/docs/upgrade.md
@@ -85,6 +85,19 @@ process, for example:
     dpkg -i matrix-synapse-py3_1.3.0+stretch1_amd64.deb
     ```
 
+# Upgrading to v1.57.0
+
+## Changes to database schema for application services
+
+Synapse v1.57.0 includes a [change](https://github.com/matrix-org/synapse/pull/12209) to the
+way transaction IDs are managed for application services. If your deployment uses a dedicated
+worker for application service traffic, **it must be stopped** when the database is upgraded
+(which normally happens when the main process is upgraded), to ensure the change is made safely
+without any risk of reusing transaction IDs.
+
+Deployments which do not use separate worker processes can be upgraded as normal. Similarly,
+deployments where no applciation services are in use can be upgraded as normal.
+
 # Upgrading to v1.56.0
 
 ## Open registration without verification is now disabled by default
diff --git a/docs/workers.md b/docs/workers.md
index 8ac95e39bb..caef44b614 100644
--- a/docs/workers.md
+++ b/docs/workers.md
@@ -27,7 +27,7 @@ feeds streams of newly written data between processes so they can be kept in
 sync with the database state.
 
 When configured to do so, Synapse uses a
-[Redis pub/sub channel](https://redis.io/topics/pubsub) to send the replication
+[Redis pub/sub channel](https://redis.io/docs/manual/pubsub/) to send the replication
 stream between all configured Synapse processes. Additionally, processes may
 make HTTP requests to each other, primarily for operations which need to wait
 for a reply ─ such as sending an event.