diff --git a/lib/reducers/db-ops-reducer.test.js b/lib/reducers/db-ops-reducer.test.js
--- a/lib/reducers/db-ops-reducer.test.js
+++ b/lib/reducers/db-ops-reducer.test.js
@@ -15,6 +15,7 @@
   integrityStoreOperations: [],
   syncedMetadataStoreOperations: [],
   auxUserStoreOperations: [],
+  threadActivityStoreOperations: [],
 };
 
 describe('DB ops reducer', () => {
diff --git a/lib/reducers/master-reducer.js b/lib/reducers/master-reducer.js
--- a/lib/reducers/master-reducer.js
+++ b/lib/reducers/master-reducer.js
@@ -181,10 +181,8 @@
     action,
   );
 
-  const { threadActivityStore } = reduceThreadActivity(
-    state.threadActivityStore,
-    action,
-  );
+  const { threadActivityStore, threadActivityStoreOperations } =
+    reduceThreadActivity(state.threadActivityStore, action);
 
   return {
     state: {
@@ -237,6 +235,7 @@
       integrityStoreOperations,
       syncedMetadataStoreOperations,
       auxUserStoreOperations,
+      threadActivityStoreOperations,
     },
   };
 }
diff --git a/lib/types/store-ops-types.js b/lib/types/store-ops-types.js
--- a/lib/types/store-ops-types.js
+++ b/lib/types/store-ops-types.js
@@ -51,6 +51,7 @@
   ClientDBSyncedMetadataStoreOperation,
 } from '../ops/synced-metadata-store-ops.js';
 import type {
+  ThreadActivityStoreOperation,
   ClientDBThreadActivityEntry,
   ClientDBThreadActivityStoreOperation,
 } from '../ops/thread-activity-store-ops.js';
@@ -75,6 +76,7 @@
   +integrityStoreOperations: $ReadOnlyArray<IntegrityStoreOperation>,
   +syncedMetadataStoreOperations: $ReadOnlyArray<ClientDBSyncedMetadataStoreOperation>,
   +auxUserStoreOperations: $ReadOnlyArray<AuxUserStoreOperation>,
+  +threadActivityStoreOperations: $ReadOnlyArray<ThreadActivityStoreOperation>,
 };
 
 export type ClientDBStoreOperations = {
diff --git a/native/redux/redux-setup.js b/native/redux/redux-setup.js
--- a/native/redux/redux-setup.js
+++ b/native/redux/redux-setup.js
@@ -302,6 +302,7 @@
     integrityStoreOperations,
     syncedMetadataStoreOperations,
     auxUserStoreOperations,
+    threadActivityStoreOperations,
   } = storeOperations;
 
   const fixUnreadActiveThreadResult = fixUnreadActiveThread(state, action);
@@ -323,6 +324,7 @@
     integrityStoreOperations,
     syncedMetadataStoreOperations,
     auxUserStoreOperations,
+    threadActivityStoreOperations,
   };
   state = {
     ...state,
diff --git a/native/redux/redux-utils.js b/native/redux/redux-utils.js
--- a/native/redux/redux-utils.js
+++ b/native/redux/redux-utils.js
@@ -12,6 +12,7 @@
 import { messageStoreOpsHandlers } from 'lib/ops/message-store-ops.js';
 import { reportStoreOpsHandlers } from 'lib/ops/report-store-ops.js';
 import { syncedMetadataStoreOpsHandlers } from 'lib/ops/synced-metadata-store-ops.js';
+import { threadActivityStoreOpsHandlers } from 'lib/ops/thread-activity-store-ops.js';
 import { threadStoreOpsHandlers } from 'lib/ops/thread-store-ops.js';
 import { userStoreOpsHandlers } from 'lib/ops/user-store-ops.js';
 import type { StoreOperations } from 'lib/types/store-ops-types.js';
@@ -41,6 +42,7 @@
     communityStoreOperations,
     syncedMetadataStoreOperations,
     auxUserStoreOperations,
+    threadActivityStoreOperations,
   } = storeOperations;
 
   const convertedThreadStoreOperations =
@@ -65,6 +67,10 @@
     integrityStoreOpsHandlers.convertOpsToClientDBOps(integrityStoreOperations);
   const convertedAuxUserStoreOperations =
     auxUserStoreOpsHandlers.convertOpsToClientDBOps(auxUserStoreOperations);
+  const convertedThreadActivityStoreOperations =
+    threadActivityStoreOpsHandlers.convertOpsToClientDBOps(
+      threadActivityStoreOperations,
+    );
 
   try {
     const promises = [];
@@ -141,6 +147,13 @@
         ),
       );
     }
+    if (convertedThreadActivityStoreOperations.length > 0) {
+      promises.push(
+        commCoreModule.processThreadActivityStoreOperations(
+          convertedThreadActivityStoreOperations,
+        ),
+      );
+    }
     await Promise.all(promises);
   } catch (e) {
     if (isTaskCancelledError(e)) {
diff --git a/web/redux/initial-state-gate.js b/web/redux/initial-state-gate.js
--- a/web/redux/initial-state-gate.js
+++ b/web/redux/initial-state-gate.js
@@ -164,6 +164,7 @@
               integrityStoreOperations: [],
               syncedMetadataStoreOperations: [],
               auxUserStoreOperations: [],
+              threadActivityStoreOperations: [],
             },
             currentLoggedInUserID,
           );
diff --git a/web/redux/redux-setup.js b/web/redux/redux-setup.js
--- a/web/redux/redux-setup.js
+++ b/web/redux/redux-setup.js
@@ -161,6 +161,7 @@
     integrityStoreOperations: [],
     syncedMetadataStoreOperations: [],
     auxUserStoreOperations: [],
+    threadActivityStoreOperations: [],
   };
 
   if (
diff --git a/web/shared-worker/utils/store.js b/web/shared-worker/utils/store.js
--- a/web/shared-worker/utils/store.js
+++ b/web/shared-worker/utils/store.js
@@ -7,6 +7,7 @@
 import { messageStoreOpsHandlers } from 'lib/ops/message-store-ops.js';
 import { reportStoreOpsHandlers } from 'lib/ops/report-store-ops.js';
 import { syncedMetadataStoreOpsHandlers } from 'lib/ops/synced-metadata-store-ops.js';
+import { threadActivityStoreOpsHandlers } from 'lib/ops/thread-activity-store-ops.js';
 import { threadStoreOpsHandlers } from 'lib/ops/thread-store-ops.js';
 import { userStoreOpsHandlers } from 'lib/ops/user-store-ops.js';
 import { canUseDatabaseOnWeb } from 'lib/shared/web-database.js';
@@ -140,6 +141,7 @@
     auxUserStoreOperations,
     userStoreOperations,
     messageStoreOperations,
+    threadActivityStoreOperations,
   } = storeOperations;
 
   const canUseDatabase = canUseDatabaseOnWeb(userID);
@@ -165,6 +167,10 @@
     userStoreOpsHandlers.convertOpsToClientDBOps(userStoreOperations);
   const convertedMessageStoreOperations =
     messageStoreOpsHandlers.convertOpsToClientDBOps(messageStoreOperations);
+  const convertedThreadActivityStoreOperations =
+    threadActivityStoreOpsHandlers.convertOpsToClientDBOps(
+      threadActivityStoreOperations,
+    );
 
   if (
     convertedThreadStoreOperations.length === 0 &&
@@ -176,7 +182,8 @@
     convertedSyncedMetadataStoreOperations.length === 0 &&
     convertedAuxUserStoreOperations.length === 0 &&
     convertedUserStoreOperations.length === 0 &&
-    convertedMessageStoreOperations.length === 0
+    convertedMessageStoreOperations.length === 0 &&
+    convertedThreadActivityStoreOperations.length === 0
   ) {
     return;
   }
@@ -200,6 +207,7 @@
         auxUserStoreOperations: convertedAuxUserStoreOperations,
         userStoreOperations: convertedUserStoreOperations,
         messageStoreOperations: convertedMessageStoreOperations,
+        threadActivityStoreOperations: convertedThreadActivityStoreOperations,
       },
     });
   } catch (e) {