diff --git a/api_server/utils/query_params.py b/api_server/utils/query_params.py
new file mode 100644
index 000000000..1f0b6a80e
--- /dev/null
+++ b/api_server/utils/query_params.py
@@ -0,0 +1,12 @@
+from collections.abc import Mapping
+
+
+def parse_optional_int_query_param(query: Mapping[str, str], name: str) -> int | None:
+    value = query.get(name)
+    if value is None:
+        return None
+
+    try:
+        return int(value)
+    except (TypeError, ValueError) as exc:
+        raise ValueError(f"{name} must be an integer") from exc
diff --git a/server.py b/server.py
index 881da8e66..565fa5dc2 100644
--- a/server.py
+++ b/server.py
@@ -45,6 +45,7 @@ from app.subgraph_manager import SubgraphManager
 from app.node_replace_manager import NodeReplaceManager
 from typing import Optional, Union
 from api_server.routes.internal.internal_routes import InternalRoutes
+from api_server.utils.query_params import parse_optional_int_query_param
 from protocol import BinaryEventTypes
 
 # Import cache control middleware
@@ -887,14 +888,15 @@ class PromptServer():
 
         @routes.get("/history")
         async def get_history(request):
-            max_items = request.rel_url.query.get("max_items", None)
-            if max_items is not None:
-                max_items = int(max_items)
+            query = request.rel_url.query
 
-            offset = request.rel_url.query.get("offset", None)
-            if offset is not None:
-                offset = int(offset)
-            else:
+            try:
+                max_items = parse_optional_int_query_param(query, "max_items")
+                offset = parse_optional_int_query_param(query, "offset")
+            except ValueError as exc:
+                return web.json_response({"error": str(exc)}, status=400)
+
+            if offset is None:
                 offset = -1
 
             return web.json_response(self.prompt_queue.get_history(max_items=max_items, offset=offset))
diff --git a/tests-unit/server/utils/query_params_test.py b/tests-unit/server/utils/query_params_test.py
new file mode 100644
index 000000000..558c6812b
--- /dev/null
+++ b/tests-unit/server/utils/query_params_test.py
@@ -0,0 +1,39 @@
+import pytest
+
+from api_server.utils.query_params import parse_optional_int_query_param
+
+
+def test_parse_optional_int_query_param_returns_none_when_missing():
+    assert parse_optional_int_query_param({}, "offset") is None
+
+
+@pytest.mark.parametrize(
+    ("raw_value", "expected"),
+    [
+        ("0", 0),
+        ("5", 5),
+        ("-1", -1),
+    ],
+)
+def test_parse_optional_int_query_param_parses_integers(raw_value, expected):
+    query = {"offset": raw_value}
+
+    assert parse_optional_int_query_param(query, "offset") == expected
+
+
+@pytest.mark.parametrize(
+    ("name", "raw_value"),
+    [
+        ("offset", "not-an-integer"),
+        ("offset", "1.5"),
+        ("offset", ""),
+        ("max_items", "not-an-integer"),
+    ],
+)
+def test_parse_optional_int_query_param_rejects_invalid_integers(name, raw_value):
+    query = {name: raw_value}
+
+    with pytest.raises(ValueError) as exc_info:
+        parse_optional_int_query_param(query, name)
+
+    assert str(exc_info.value) == f"{name} must be an integer"
diff --git a/tests/execution/test_execution.py b/tests/execution/test_execution.py
index f73ca7e3c..3e16ccec6 100644
--- a/tests/execution/test_execution.py
+++ b/tests/execution/test_execution.py
@@ -909,6 +909,20 @@ class TestExecution:
 
         assert len(result) <= 1, "Should return at most 1 item when offset is near end"
 
+    def test_history_api_rejects_non_integer_max_items(self, client: ComfyClient):
+        with pytest.raises(urllib.error.HTTPError) as exc_info:
+            client.get_all_history(max_items="not-an-integer")
+
+        assert exc_info.value.code == 400
+        assert json.loads(exc_info.value.read()) == {"error": "max_items must be an integer"}
+
+    def test_history_api_rejects_non_integer_offset(self, client: ComfyClient):
+        with pytest.raises(urllib.error.HTTPError) as exc_info:
+            client.get_all_history(offset="not-an-integer")
+
+        assert exc_info.value.code == 400
+        assert json.loads(exc_info.value.read()) == {"error": "offset must be an integer"}
+
     # Jobs API tests
     def test_jobs_api_job_structure(
         self, client: ComfyClient, builder: GraphBuilder