Add module API callbacks for adding and deleting local 3PID associations (#15044

2 files changed, 68 insertions, 1 deletions

diff --git a/docs/modules/third_party_rules_callbacks.md b/docs/modules/third_party_rules_callbacks.md
index 888e43bd10..4a27d976fb 100644
--- a/docs/modules/third_party_rules_callbacks.md
+++ b/docs/modules/third_party_rules_callbacks.md
@@ -254,6 +254,11 @@ If multiple modules implement this callback, Synapse runs them all in order.
 
 _First introduced in Synapse v1.56.0_
 
+**<span style="color:red">
+This callback is deprecated in favour of the `on_add_user_third_party_identifier` callback, which
+features the same functionality. The only difference is in name.
+</span>**
+
 ```python
 async def on_threepid_bind(user_id: str, medium: str, address: str) -> None:
 ```
@@ -268,6 +273,44 @@ server_.
 
 If multiple modules implement this callback, Synapse runs them all in order.
 
+### `on_add_user_third_party_identifier`
+
+_First introduced in Synapse v1.79.0_
+
+```python
+async def on_add_user_third_party_identifier(user_id: str, medium: str, address: str) -> None:
+```
+
+Called after successfully creating an association between a 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 (i.e. an email address).
+
+Note that this callback is _not_ called if a user attempts to bind their third-party identifier
+to an identity server (via a call to [`POST
+/_matrix/client/v3/account/3pid/bind`](https://spec.matrix.org/v1.5/client-server-api/#post_matrixclientv3account3pidbind)).
+
+If multiple modules implement this callback, Synapse runs them all in order.
+
+### `on_remove_user_third_party_identifier`
+
+_First introduced in Synapse v1.79.0_
+
+```python
+async def on_remove_user_third_party_identifier(user_id: str, medium: str, address: str) -> None:
+```
+
+Called after successfully removing an association between a 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 (i.e. an email address).
+
+Note that this callback is _not_ called if a user attempts to unbind their third-party
+identifier from an identity server (via a call to [`POST
+/_matrix/client/v3/account/3pid/unbind`](https://spec.matrix.org/v1.5/client-server-api/#post_matrixclientv3account3pidunbind)).
+
+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
@@ -300,4 +343,4 @@ class EventCensorer:
         )
         event_dict["content"] = new_event_content
         return event_dict
-```
+```
\ No newline at end of file
diff --git a/docs/upgrade.md b/docs/upgrade.md
index 15167b8c58..f06e874054 100644
--- a/docs/upgrade.md
+++ b/docs/upgrade.md
@@ -88,6 +88,30 @@ process, for example:
     dpkg -i matrix-synapse-py3_1.3.0+stretch1_amd64.deb
     ```
 
+# Upgrading to v1.79.0
+
+## The `on_threepid_bind` module callback method has been deprecated
+
+Synapse v1.79.0 deprecates the
+[`on_threepid_bind`](modules/third_party_rules_callbacks.md#on_threepid_bind)
+"third-party rules" Synapse module callback method in favour of a new module method,
+[`on_add_user_third_party_identifier`](modules/third_party_rules_callbacks.md#on_add_user_third_party_identifier).
+`on_threepid_bind` will be removed in a future version of Synapse. You should check whether any Synapse
+modules in use in your deployment are making use of `on_threepid_bind`, and update them where possible.
+
+The arguments and functionality of the new method are the same.
+
+The justification behind the name change is that the old method's name, `on_threepid_bind`, was
+misleading. A user is considered to "bind" their third-party ID to their Matrix ID only if they
+do so via an [identity server](https://spec.matrix.org/latest/identity-service-api/)
+(so that users on other homeservers may find them). But this method was not called in that case -
+it was only called when a user added a third-party identifier on the local homeserver.
+
+Module developers may also be interested in the related
+[`on_remove_user_third_party_identifier`](modules/third_party_rules_callbacks.md#on_remove_user_third_party_identifier)
+module callback method that was also added in Synapse v1.79.0. This new method is called when a
+user removes a third-party identifier from their account.
+
 # Upgrading to v1.78.0
 
 ## Deprecate the `/_synapse/admin/v1/media/<server_name>/delete` admin API