diff --git a/app.py b/app.py
index 2e3dd9b..8cf9b21 100644
--- a/app.py
+++ b/app.py
@@ -134,10 +134,8 @@ async def sign_endpoint(request: Request):
     data = json_data.get("data")
     a1 = json_data.get("a1")
     web_session = json_data.get("web_session")
-    
-    if not all([uri, data, a1, web_session]):
-        raise HTTPException(status_code=400, detail="Missing required parameters")
-    
+    if not uri or not a1: 
+        raise HTTPException(status_code=400, detail="Missing required parameters")    
     me = await sign(uri, data, a1, web_session)
     return {
         "a1": a1,