1 files changed, 22 insertions, 0 deletions
diff --git a/synapse/streams/__init__.py b/synapse/streams/__init__.py
index 5e83dba2ed..806b671305 100644
--- a/synapse/streams/__init__.py
+++ b/synapse/streams/__init__.py
@@ -11,3 +11,25 @@
 # 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 typing import Collection, Generic, List, Optional, Tuple, TypeVar
+
+from synapse.types import UserID
+
+# The key, this is either a stream token or int.
+K = TypeVar("K")
+# The return type.
+R = TypeVar("R")
+
+
+class EventSource(Generic[K, R]):
+    async def get_new_events(
+        self,
+        user: UserID,
+        from_key: K,
+        limit: Optional[int],
+        room_ids: Collection[str],
+        is_guest: bool,
+        explicit_room_id: Optional[str] = None,
+    ) -> Tuple[List[R], K]:
+        ...