diff --git a/src/service/rooms/pdu_metadata/mod.rs b/src/service/rooms/pdu_metadata/mod.rs
new file mode 100644
index 00000000..f8ffcee1
--- /dev/null
+++ b/src/service/rooms/pdu_metadata/mod.rs
@@ -0,0 +1,31 @@
+
+    #[tracing::instrument(skip(self, room_id, event_ids))]
+    pub fn mark_as_referenced(&self, room_id: &RoomId, event_ids: &[Arc<EventId>]) -> Result<()> {
+        for prev in event_ids {
+            let mut key = room_id.as_bytes().to_vec();
+            key.extend_from_slice(prev.as_bytes());
+            self.referencedevents.insert(&key, &[])?;
+        }
+
+        Ok(())
+    }
+
+    #[tracing::instrument(skip(self))]
+    pub fn is_event_referenced(&self, room_id: &RoomId, event_id: &EventId) -> Result<bool> {
+        let mut key = room_id.as_bytes().to_vec();
+        key.extend_from_slice(event_id.as_bytes());
+        Ok(self.referencedevents.get(&key)?.is_some())
+    }
+
+    #[tracing::instrument(skip(self))]
+    pub fn mark_event_soft_failed(&self, event_id: &EventId) -> Result<()> {
+        self.softfailedeventids.insert(event_id.as_bytes(), &[])
+    }
+
+    #[tracing::instrument(skip(self))]
+    pub fn is_event_soft_failed(&self, event_id: &EventId) -> Result<bool> {
+        self.softfailedeventids
+            .get(event_id.as_bytes())
+            .map(|o| o.is_some())
+    }
+