diff --git a/src/ionbeam/core/aviso.py b/src/ionbeam/core/aviso.py
new file mode 100644
index 0000000..ed91211
--- /dev/null
+++ b/src/ionbeam/core/aviso.py
@@ -0,0 +1,19 @@
+import requests
+from typing import Any
+from datetime import datetime
+
+
+def send_aviso_notification(request: dict[str, Any]):
+    notification = {
+        "type": "aviso",
+        "data": {"event": "iot-data", "request": request},
+        "datacontenttype": "application/json",
+        "id": "0c02fdc5-148c-43b5-b2fa-cb1f590369ff",
+        "source": "/host/user",
+        "specversion": "1.0",
+        "time": datetime.utcnow().isoformat(timespec="milliseconds") + "Z",
+    }
+
+    response = requests.post("https://iot-notifications.ecmwf.int/api/v1/notification", json=notification)
+    # response.raise_for_status()
+    return response
diff --git a/src/ionbeam/writers/mars_client_writer.py b/src/ionbeam/writers/mars_client_writer.py
index b40a6d9..63ad3fc 100644
--- a/src/ionbeam/writers/mars_client_writer.py
+++ b/src/ionbeam/writers/mars_client_writer.py
@@ -15,6 +15,7 @@
 import dataclasses
 
 from ..core.bases import Writer, Message, FileMessage, FinishMessage
+from ..core.aviso import send_aviso_notification
 
 import logging
 
@@ -97,7 +98,7 @@ def process(self, message: FileMessage | FinishMessage) -> Iterable[Message]:
             logger.debug(mars_request)
             run_temp_mars_request(file=fp.name)
 
-        # send an aviso notification here
+        response = send_aviso_notification(request)
 
         # TODO: the explicit mars_keys should not be necessary here.
         metadata = self.generate_metadata(message, mars_keys=message.metadata.mars_keys)