diff --git a/packages/jupyter-ai/jupyter_ai/completions/handlers/default.py b/packages/jupyter-ai/jupyter_ai/completions/handlers/default.py
index eb03df15..b393fc66 100644
--- a/packages/jupyter-ai/jupyter_ai/completions/handlers/default.py
+++ b/packages/jupyter-ai/jupyter_ai/completions/handlers/default.py
@@ -42,7 +42,7 @@ def create_llm_chain(
     async def handle_request(self, request: InlineCompletionRequest) -> None:
         """Handles an inline completion request without streaming."""
         self.get_llm_chain()
-        model_arguments = self._template_inputs_from_request(request)
+        model_arguments = await self._template_inputs_from_request(request)
         suggestion = await self.llm_chain.ainvoke(input=model_arguments)
         suggestion = self._post_process_suggestion(suggestion, request)
         self.write_message(
@@ -80,7 +80,7 @@ async def handle_stream_request(self, request: InlineCompletionRequest):
         # then, generate and stream LLM output over this connection.
         self.get_llm_chain()
         token = self._token_from_request(request, 0)
-        model_arguments = self._template_inputs_from_request(request)
+        model_arguments = await self._template_inputs_from_request(request)
         suggestion = ""
 
         async for fragment in self.llm_chain.astream(input=model_arguments):
@@ -115,12 +115,71 @@ def _token_from_request(self, request: InlineCompletionRequest, suggestion: int)
         using request number and suggestion number"""
         return f"t{request.number}s{suggestion}"
 
-    def _template_inputs_from_request(self, request: InlineCompletionRequest) -> Dict:
+    async def _get_document(self, request: InlineCompletionRequest):
+        collaboration = self.settings.get("jupyter_collaboration", None)
+        file_id_manager = self.settings.get("file_id_manager", None)
+
+        if not collaboration or not file_id_manager or not request.path:
+            return None
+
+        from jupyter_collaboration.rooms import DocumentRoom
+        from jupyter_collaboration.utils import encode_file_path
+        from jupyter_collaboration.websocketserver import RoomNotFound
+
+        file_id = file_id_manager.index(request.path)
+        is_notebook = request.path.endswith("ipynb")
+        content_type = "notebook" if is_notebook else "file"
+        file_format = "json" if is_notebook else "text"
+
+        encoded_path = encode_file_path(file_format, content_type, file_id)
+        room_id: str = encoded_path.split("/")[-1]
+
+        try:
+            room = await collaboration.ywebsocket_server.get_room(room_id)
+        except RoomNotFound:
+            return None
+
+        if isinstance(room, DocumentRoom):
+            document = room._document
+            return document
+
+    async def _template_inputs_from_request(
+        self, request: InlineCompletionRequest
+    ) -> Dict:
+        prefix = request.prefix
         suffix = request.suffix.strip()
         filename = request.path.split("/")[-1] if request.path else "untitled"
 
+        document = await self._get_document(request)
+
+        if document:
+            from jupyter_ydoc import YNotebook
+
+        if document and isinstance(document, YNotebook):
+            cell_type = "markdown" if request.language == "markdown" else "code"
+
+            is_before_request_cell = True
+            before = []
+            after = [suffix]
+
+            for cell in document.ycells:
+                if is_before_request_cell and cell["id"] == request.cell_id:
+                    is_before_request_cell = False
+                    continue
+                if cell["cell_type"] != cell_type:
+                    continue
+                source = cell["source"].to_py()
+                if is_before_request_cell:
+                    before.append(source)
+                else:
+                    after.append(source)
+
+            before.append(prefix)
+            prefix = "\n\n".join(before)
+            suffix = "\n\n".join(after)
+
         return {
-            "prefix": request.prefix,
+            "prefix": prefix,
             "suffix": suffix,
             "language": request.language,
             "filename": filename,