diff --git a/machines/eb-app-ui/home/ui/galaxy-dev/src/lib/pri/intercom.ts b/machines/eb-app-ui/home/ui/galaxy-dev/src/lib/pri/intercom.ts
new file mode 100644
index 00000000..f922cc51
--- /dev/null
+++ b/machines/eb-app-ui/home/ui/galaxy-dev/src/lib/pri/intercom.ts
@@ -0,0 +1,94 @@
+import { getById, list } from "$lib/api";
+import { isOver } from "$lib/common";
+import type { IntercomMessage } from "$lib/types";
+
+// -----------------------------------------------------------------------------
+export function updateMessageList() {
+  const list: IntercomMessage[] = [];
+
+  for (const key in globalThis.localStorage) {
+    try {
+      if (!key.match("^msg-")) continue;
+
+      const value = globalThis.localStorage.getItem(key);
+      if (!value) throw "empty message";
+
+      const parsedValue = JSON.parse(value) as IntercomMessage;
+      list.push(parsedValue);
+    } catch {
+      globalThis.localStorage.removeItem(key);
+    }
+  }
+
+  return list;
+}
+
+// -----------------------------------------------------------------------------
+export async function watchCall(msgId: string) {
+  try {
+    // this will fail if the call message is already deleted
+    const msg = await getById("/api/pri/intercom/get", msgId);
+    if (msg.status !== "none") throw "invalid status";
+
+    const expiredAt = new Date(msg.expired_at);
+    if (isOver(expiredAt)) throw "expired call";
+
+    setTimeout(() => {
+      watchCall(msgId);
+    }, 2000);
+  } catch {
+    delCallMessage(msgId);
+  }
+}
+
+// -----------------------------------------------------------------------------
+function addCallMessage(msg: IntercomMessage) {
+  try {
+    const isExist = globalThis.localStorage.getItem(`msg-${msg.id}`);
+    if (isExist) return;
+
+    globalThis.localStorage.setItem(`msg-${msg.id}`, JSON.stringify(msg));
+    document.dispatchEvent(new CustomEvent("internalMessage"));
+  } catch {
+    // do nothing
+  }
+}
+
+// -----------------------------------------------------------------------------
+function delCallMessage(msgId: string) {
+  try {
+    globalThis.localStorage.removeItem(`msg-${msgId}`);
+    document.dispatchEvent(new CustomEvent("internalMessage"));
+  } catch {
+    // do nothing
+  }
+}
+
+// -----------------------------------------------------------------------------
+export async function intercomHandler() {
+  try {
+    const now = new Date().getTime();
+    const checkedAt =
+      globalThis.localStorage.getItem("intercom_checked_at") || "0";
+
+    if (isNaN(Number(checkedAt))) {
+      globalThis.localStorage.setItem("intercom_checked_at", String(now));
+    }
+
+    if (now - Number(checkedAt) > 3000) {
+      globalThis.localStorage.setItem("intercom_checked_at", String(now));
+
+      const messages: IntercomMessage[] = await list(
+        "/api/pri/intercom/list",
+        10,
+      );
+      for (const msg of messages) {
+        if (msg.message_type === "call") {
+          addCallMessage(msg);
+        }
+      }
+    }
+  } finally {
+    setTimeout(intercomHandler, 3000);
+  }
+}