Add submit_url response parameter to msisdn /requestToken

changelog.d/6079.feature

@@ -0,0 +1 @@
+Add `submit_url` response parameter to /account/3pid/msisdn/requestToken`.

docs/sample_config.yaml

@@ -937,6 +937,8 @@ uploads_path: "DATADIR/uploads"
 # by the Matrix Identity Service API specification:
 # https://matrix.org/docs/spec/identity_service/latest
 #
+# If a delegate is specified, the config option public_baseurl must also be filled out.
+#
 account_threepid_delegates:
     #email: https://example.com     # Delegate email sending to example.org
     #msisdn: http://localhost:8090  # Delegate SMS sending to this local process

synapse/config/registration.py

@@ -293,6 +293,8 @@ def generate_config_section(self, generate_secrets=False, **kwargs):
         # by the Matrix Identity Service API specification:
         # https://matrix.org/docs/spec/identity_service/latest
         #
+        # If a delegate is specified, the config option public_baseurl must also be filled out.
+        #
         account_threepid_delegates:
             #email: https://example.com     # Delegate email sending to example.org
             #msisdn: http://localhost:8090  # Delegate SMS sending to this local process

synapse/rest/client/v2_alpha/account.py

@@ -521,6 +521,14 @@ def on_POST(self, request):
             next_link,
         )
 
+        assert self.hs.config.public_baseurl
+
+        # Add submit_url response parameter as per MSC2078
+        ret["submit_url"] = (
+            self.hs.config.public_baseurl
+            + "_matrix/client/unstable/add_threepid/msisdn/submit_token"
+        )
+
         return 200, ret