diff --git a/jupyter_ydoc/ynotebook.py b/jupyter_ydoc/ynotebook.py
index 7452263..b6f192d 100644
--- a/jupyter_ydoc/ynotebook.py
+++ b/jupyter_ydoc/ynotebook.py
@@ -38,6 +38,12 @@ class YNotebook(YBaseDoc):
                     "cell_type": str,
                     "source": YText,
                     "metadata": YMap,
+                    "pending_requests": YArray[
+                        YMap[
+                            "id": str,
+                            "type": str
+                        ]
+                    ],
                     "execution_count": Int | None,
                     "outputs": [] | None,
                     "attachments": {} | None
@@ -100,6 +106,9 @@ def get_cell(self, index: int) -> Dict[str, Any]:
         """
         meta = self._ymeta.to_py()
         cell = self._ycells[index].to_py()
+        if "pending_requests" in cell:
+            # requests are not a part of notebook format, but a run-time only property
+            del cell["pending_requests"]
         cast_all(cell, float, int)  # cells coming from Yjs have e.g. execution_count as float
         if "id" in cell and meta["nbformat"] == 4 and meta["nbformat_minor"] <= 4:
             # strip cell IDs if we have notebook format 4.0-4.4
@@ -164,6 +173,7 @@ def create_ycell(self, value: Dict[str, Any]) -> Map:
                     output["text"] = Array(output.get("text", []))
                 outputs[idx] = Map(output)
             cell["outputs"] = Array(outputs)
+            cell["pending_requests"] = Array()
 
         return Map(cell)