diff --git a/src/main/frontend/handler/worker.cljs b/src/main/frontend/handler/worker.cljs
new file mode 100644
index 000000000..0972a9726
--- /dev/null
+++ b/src/main/frontend/handler/worker.cljs
@@ -0,0 +1,26 @@
+(ns frontend.handler.worker
+  (:require [cljs-bean.core :as bean]
+            [frontend.handler.file :as file-handler]
+            [frontend.handler.notification :as notification]
+            [clojure.edn :as edn]))
+
+(defmulti handle identity)
+
+(defmethod handle :write-files [_ {:keys [repo files]}]
+  (file-handler/alter-files repo files {}))
+
+(defmethod handle :notification [_ data]
+  (apply notification/show! (edn/read-string data)))
+
+(defmethod handle :default [_ data]
+  (prn :debug "Worker data not handled: " data))
+
+(defn handle-message!
+  [^js worker]
+  (assert worker "worker doesn't exists")
+  (set! (.-onmessage worker)
+        (fn [event]
+          (let [data (.-data event)]
+            (when-not (= (.-type data) "RAW")
+              (let [[e payload] (bean/->clj data)]
+                (handle (keyword e) payload)))))))
diff --git a/src/main/frontend/persist_db/browser.cljs b/src/main/frontend/persist_db/browser.cljs
index 92f813cc4..dd29a119f 100644
--- a/src/main/frontend/persist_db/browser.cljs
+++ b/src/main/frontend/persist_db/browser.cljs
@@ -12,7 +12,8 @@
             [frontend.state :as state]
             [electron.ipc :as ipc]
             [frontend.modules.outliner.datascript :as outliner-db]
-            [clojure.edn :as edn]))
+            [clojure.edn :as edn]
+            [frontend.handler.worker :as worker-handler]))
 
 (defonce *sqlite (atom nil))
 
@@ -31,6 +32,7 @@
                        "/static/js/db-worker.js")
           worker (js/Worker. (str worker-url "?electron=" (util/electron?)))
           sqlite (Comlink/wrap worker)]
+      (worker-handler/handle-message! worker)
       (reset! *sqlite sqlite)
       (-> (p/let [_ (.init sqlite)]
             (ask-persist-permission!))
diff --git a/src/main/frontend/worker/file.cljs b/src/main/frontend/worker/file.cljs
index 738465361..1e1f47a11 100644
--- a/src/main/frontend/worker/file.cljs
+++ b/src/main/frontend/worker/file.cljs
@@ -11,7 +11,8 @@
             [datascript.core :as d]
             [logseq.db :as ldb]
             [malli.core :as m]
-            [frontend.worker.state :as state]))
+            [frontend.worker.state :as state]
+            [goog.object :as gobj]))
 
 (defonce file-writes-chan
   (let [coercer (m/coercer [:catn
@@ -81,12 +82,12 @@
     (doseq [[repo page-id outliner-op] (set (map #(take 3 %) pages))] ; remove time to dedupe pages to write
       (try (do-write-file! repo conn page-id outliner-op context)
            (catch :default e
-             ;; FIXME: notification
-             ;; (notification/show!
-             ;;  [:div
-             ;;   [:p "Write file failed, please copy the changes to other editors in case of losing data."]
-             ;;   "Error: " (str (gobj/get e "stack"))]
-             ;;  :error)
+             (worker-util/post-message :notification
+                                       (pr-str
+                                        [[:div
+                                          [:p "Write file failed, please copy the changes to other editors in case of losing data."]
+                                          "Error: " (str (gobj/get e "stack"))]
+                                         :error]))
              (log/error :file/write-file-error {:error e}))))))
 
 (defn sync-to-file
@@ -94,7 +95,6 @@
   (when (and repo page-id
              (not (:created-from-journal-template? tx-meta))
              (not (:delete-files? tx-meta)))
-    (prn :debug :sync-to-file :repo repo :page-id page-id)
     (async/put! file-writes-chan [repo page-id (:outliner-op tx-meta) (tc/to-long (t/now))])))
 
 (defn <ratelimit-file-writes!
diff --git a/src/main/frontend/worker/file/core.cljs b/src/main/frontend/worker/file/core.cljs
index 40cc17d85..f377965d3 100644
--- a/src/main/frontend/worker/file/core.cljs
+++ b/src/main/frontend/worker/file/core.cljs
@@ -5,7 +5,8 @@
             [logseq.common.path :as path]
             [datascript.core :as d]
             [logseq.db :as ldb]
-            [frontend.worker.date :as worker-date]))
+            [frontend.worker.date :as worker-date]
+            [frontend.worker.util :as util]))
 
 (defn- indented-block-content
   [content spaces-tabs]
@@ -149,10 +150,8 @@
                           (tree->file-content repo db tree {:init-level init-level} context))]
         (when-not (and (string/blank? new-content) (not blocks-just-deleted?))
           (let [files [[file-path new-content]]]
-            (prn :debug :write-file :file-path file-path :content new-content)
-            ;; TODO: send files to main thread to save
-            ;; (file-handler/alter-files-handler! repo files {} {})
-            )))
+            (when (seq files)
+              (util/post-message :write-files {:repo repo :files files})))))
       ;; In e2e tests, "card" page in db has no :file/path
       (js/console.error "File path from page-block is not valid" page-block tree))))
 
diff --git a/src/main/frontend/worker/util.cljs b/src/main/frontend/worker/util.cljs
index 17568cd58..03112fcc7 100644
--- a/src/main/frontend/worker/util.cljs
+++ b/src/main/frontend/worker/util.cljs
@@ -9,7 +9,8 @@
             [clojure.core.async :as async]
             [cljs.core.async.impl.channels :refer [ManyToManyChannel]]
             [cljs-time.coerce :as tc]
-            [cljs-time.core :as t]))
+            [cljs-time.core :as t]
+            [cljs-bean.core :as bean]))
 
 (defonce db-version-prefix "logseq_db_")
 (defonce local-db-prefix "logseq_local_")
@@ -136,3 +137,7 @@
 (defn time-ms
   []
   (tc/to-long (t/now)))
+
+(defn post-message
+  [type data]
+  (.postMessage js/self (bean/->js [type data])))