diff --git a/app.py b/app.py
index e9962cb..e1937c0 100644
--- a/app.py
+++ b/app.py
@@ -61,6 +61,11 @@ def store_last_request(request_data, namespace="requests"):
     with open(filename, "w") as f:
         json.dump(data, f, indent=4)
 
+def check_namespace(namespace):
+    if namespace == "__history" or namespace == "__last_request" or namespace == "__clear" or namespace == "__help" or namespace == "docs" or namespace == "redoc" or namespace == "api":
+        return False
+    return True
+
 
 @app.get("/", status_code=status.HTTP_200_OK)
 @app.post("/", status_code=status.HTTP_200_OK)
@@ -77,8 +82,11 @@ def store_last_request(request_data, namespace="requests"):
 @app.options("/{namespace}", status_code=status.HTTP_200_OK)
 @app.head("/{namespace}", status_code=status.HTTP_200_OK)
 async def catch(
-    request: Request, response: Response, namespace: str = "requests"
+    request: Request, response: Response, namespace: str = "requests",
 ) -> Answer:
+    if not check_namespace(namespace):
+        response.status_code = status.HTTP_400_BAD_REQUEST
+        return Answer(status="error", message="Invalid namespace name provided.")
     try:
         json = await request.json()
     except:
@@ -121,7 +129,10 @@ def help():
 
 @app.get("/api/__last_request", status_code=status.HTTP_200_OK)
 @app.get("/api/__last_request/{namespace}", status_code=status.HTTP_200_OK)
-async def last_requests(namespace: str = "requests") -> Answer | RequestData:
+async def last_requests(response: Response, namespace: str = "requests",) -> Answer | RequestData:
+    if not check_namespace(namespace):
+        response.status_code = status.HTTP_400_BAD_REQUEST
+        return Answer(status="error", message="Invalid namespace name provided.")
     filename = f"{HISTORY_STORAGE}/{namespace}.json"
     try:
         with open(filename, "r") as f:
@@ -140,8 +151,12 @@ async def last_requests(namespace: str = "requests") -> Answer | RequestData:
 @app.get("/api/__history/{namespace}/{id}", status_code=status.HTTP_200_OK)
 @app.get("/api/__history/{namespace}", status_code=status.HTTP_200_OK)
 async def history(
-    id: int = 0, namespace: str = "requests"
+    response: Response,
+    id: int = 0, namespace: str = "requests",
 ) -> Answer | RequestData | list[RequestData]:
+    if not check_namespace(namespace):
+        response.status_code = status.HTTP_400_BAD_REQUEST
+        return Answer(status="error", message="Invalid namespace name provided.")
     filename = f"{HISTORY_STORAGE}/{namespace}.json"
     try:
         with open(filename, "r") as f:
@@ -158,7 +173,11 @@ async def history(
 
 @app.get("/api/__clear", status_code=status.HTTP_200_OK)
 @app.get("/api/__clear/{namespace}", status_code=status.HTTP_200_OK)
-async def clear_history(namespace: str = "requests") -> Answer:
+async def clear_history(response: Response,
+    namespace: str = "requests",) -> Answer:
+    if not check_namespace(namespace):
+        response.status_code = status.HTTP_400_BAD_REQUEST
+        return Answer(status="error", message="Invalid namespace name provided.")
     filename = f"{HISTORY_STORAGE}/{namespace}.json"
     with open(filename, "w") as f:
         json.dump([], f)