diff --git a/register_agents.py b/register_agents.py
index 972e3aa..2b1f8c2 100755
--- a/register_agents.py
+++ b/register_agents.py
@@ -45,6 +45,7 @@ def parse_iso(value: Any) -> Optional[str]:
     Best-effort: return ISO8601 string or None.
     - If value is already a string, return it (assuming it's already ISO8601).
     - If value looks like 'ISODate(\"...\")', extract the inner string.
+    - If value is Extended JSON format { "$date": "..." }, extract the date string.
     - Otherwise, return None.
     """
     if value is None:
@@ -53,6 +54,11 @@ def parse_iso(value: Any) -> Optional[str]:
         # Handle Mongo shell export style: ISODate('2025-07-09T06:33:12.682Z')
         m = re.match(r"^ISODate\(['\"]?([^'\"]+)['\"]?\)$", value.strip())
         return m.group(1) if m else value
+    # Handle Extended JSON format: { "$date": "2025-07-09T06:33:12.682Z" }
+    if isinstance(value, dict) and "$date" in value:
+        date_val = value["$date"]
+        if isinstance(date_val, str):
+            return date_val
     # Could try to parse datetime objects here if needed; for now, prefer string passthrough
     return None