1 files changed, 5 insertions, 0 deletions
diff --git a/synapse/handlers/sso.py b/synapse/handlers/sso.py
index 6ef459acff..415b1c2d17 100644
--- a/synapse/handlers/sso.py
+++ b/synapse/handlers/sso.py
@@ -98,6 +98,11 @@ class SsoIdentityProvider(Protocol):
         """Optional branding identifier"""
         return None
 
+    @property
+    def unstable_idp_brand(self) -> Optional[str]:
+        """Optional brand identifier for the unstable API (see MSC2858)."""
+        return None
+
     @abc.abstractmethod
     async def handle_redirect_request(
         self,