diff --git a/packages/opal-client/opal_client/callbacks/reporter.py b/packages/opal-client/opal_client/callbacks/reporter.py
index 5e206d3b3..264f45b51 100644
--- a/packages/opal-client/opal_client/callbacks/reporter.py
+++ b/packages/opal-client/opal_client/callbacks/reporter.py
@@ -1,5 +1,5 @@
 import json
-from typing import List, Optional
+from typing import Any, Awaitable, Callable, Dict, List, Optional
 
 import aiohttp
 from opal_client.callbacks.register import CallbackConfig, CallbacksRegister
@@ -9,6 +9,8 @@
 from opal_common.logger import logger
 from opal_common.schemas.data import DataUpdateReport
 
+GetUserDataHandler = Callable[[DataUpdateReport], Awaitable[Dict[str, Any]]]
+
 
 class CallbacksReporter:
     """can send a report to callbacks registered on the callback register."""
@@ -18,6 +20,7 @@ def __init__(
     ) -> None:
         self._register = register
         self._fetcher = data_fetcher or DataFetcher()
+        self._get_user_data_handler: Optional[GetUserDataHandler] = None
 
     async def start(self):
         await self._fetcher.start()
@@ -25,6 +28,11 @@ async def start(self):
     async def stop(self):
         await self._fetcher.stop()
 
+    def set_user_data_handler(self, handler: GetUserDataHandler):
+        if self._get_user_data_handler is not None:
+            logger.warning("set_user_data_handler called and already have a handler.")
+        self._get_user_data_handler = handler
+
     async def report_update_results(
         self,
         report: DataUpdateReport,
@@ -33,6 +41,9 @@ async def report_update_results(
         try:
             # all the urls that will be eventually called by the fetcher
             urls = []
+            if self._get_user_data_handler is not None:
+                report = report.copy()
+                report.user_data = await self._get_user_data_handler(report)
             report_data = report.json()
 
             # first we add the callback urls from the callback register
diff --git a/packages/opal-client/opal_client/data/updater.py b/packages/opal-client/opal_client/data/updater.py
index 544a6dc45..b26eb128e 100644
--- a/packages/opal-client/opal_client/data/updater.py
+++ b/packages/opal-client/opal_client/data/updater.py
@@ -508,3 +508,7 @@ async def _set_policy_data(
             await tx.set_policy_data(data, path=path)
         else:
             await tx.patch_policy_data(data, path=path)
+
+    @property
+    def callbacks_reporter(self) -> CallbacksReporter:
+        return self._callbacks_reporter
diff --git a/packages/opal-client/opal_client/policy/updater.py b/packages/opal-client/opal_client/policy/updater.py
index 20ee44bad..10e0dbd91 100644
--- a/packages/opal-client/opal_client/policy/updater.py
+++ b/packages/opal-client/opal_client/policy/updater.py
@@ -352,3 +352,11 @@ async def handle_policy_updates(self):
                 break
             except Exception:
                 logger.exception("Failed to update policy")
+
+    @property
+    def topics(self) -> List[str]:
+        return self._topics
+
+    @property
+    def callbacks_reporter(self) -> CallbacksReporter:
+        return self._callbacks_reporter
diff --git a/packages/opal-common/opal_common/schemas/data.py b/packages/opal-common/opal_common/schemas/data.py
index 3d5833e22..37378a984 100644
--- a/packages/opal-common/opal_common/schemas/data.py
+++ b/packages/opal-common/opal_common/schemas/data.py
@@ -176,3 +176,4 @@ class DataUpdateReport(BaseModel):
     reports: List[DataEntryReport]
     # in case this is a policy update, the new hash committed the policy store.
     policy_hash: Optional[str] = None
+    user_data: Dict[str, Any] = {}