From 9367fa5d03f42e3a1feb4d7d0de61cd1bb547fd0 Mon Sep 17 00:00:00 2001
From: Daulet Amirkhanov <damirkhanov01@gmail.com>
Date: Wed, 15 Oct 2025 16:39:48 +0100
Subject: [PATCH] Prior to search, check if knowledge graph is empty

---
 cognee/api/v1/search/search.py               | 12 +++++++++++-
 cognee/modules/data/exceptions/__init__.py   |  1 +
 cognee/modules/data/exceptions/exceptions.py | 10 ++++++++++
 3 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/cognee/api/v1/search/search.py b/cognee/api/v1/search/search.py
index 0a9e76e96..32035e612 100644
--- a/cognee/api/v1/search/search.py
+++ b/cognee/api/v1/search/search.py
@@ -1,13 +1,14 @@
 from uuid import UUID
 from typing import Union, Optional, List, Type
 
+from cognee.infrastructure.databases.graph import get_graph_engine
 from cognee.modules.engine.models.node_set import NodeSet
 from cognee.modules.users.models import User
 from cognee.modules.search.types import SearchResult, SearchType, CombinedSearchResult
 from cognee.modules.users.methods import get_default_user
 from cognee.modules.search.methods import search as search_function
 from cognee.modules.data.methods import get_authorized_existing_datasets
-from cognee.modules.data.exceptions import DatasetNotFoundError
+from cognee.modules.data.exceptions import DatasetNotFoundError, SearchOnEmptyGraphError
 
 
 async def search(
@@ -175,6 +176,15 @@ async def search(
         if not datasets:
             raise DatasetNotFoundError(message="No datasets found.")
 
+    graph_engine = await get_graph_engine()
+    edges_count = await graph_engine.count_edges()
+    nodes_count = await graph_engine.count_nodes()
+
+    if nodes_count == 0 or edges_count == 0:
+        raise SearchOnEmptyGraphError(
+            message="Knowledge graph is empty, please ensure data is added and cognified."
+        )
+
     filtered_search_results = await search_function(
         query_text=query_text,
         query_type=query_type,
diff --git a/cognee/modules/data/exceptions/__init__.py b/cognee/modules/data/exceptions/__init__.py
index 54af81070..ba943634d 100644
--- a/cognee/modules/data/exceptions/__init__.py
+++ b/cognee/modules/data/exceptions/__init__.py
@@ -9,4 +9,5 @@ from .exceptions import (
     UnauthorizedDataAccessError,
     DatasetNotFoundError,
     DatasetTypeError,
+    SearchOnEmptyGraphError,
 )
diff --git a/cognee/modules/data/exceptions/exceptions.py b/cognee/modules/data/exceptions/exceptions.py
index ac3b68e64..c2921750a 100644
--- a/cognee/modules/data/exceptions/exceptions.py
+++ b/cognee/modules/data/exceptions/exceptions.py
@@ -35,6 +35,16 @@ class DatasetNotFoundError(CogneeValidationError):
         super().__init__(message, name, status_code)
 
 
+class SearchOnEmptyGraphError(CogneeValidationError):
+    def __init__(
+        self,
+        message: str = "Knowledge graph is empty, please ensure data is added and cognified.",
+        name: str = "SearchOnEmptyGraphError",
+        status_code=status.HTTP_400_BAD_REQUEST,
+    ):
+        super().__init__(message, name, status_code)
+
+
 class DatasetTypeError(CogneeValidationError):
     def __init__(
         self,