diff --git a/picoapi/api.py b/picoapi/api.py
index 7ec0ae0..5bc1aa5 100644
--- a/picoapi/api.py
+++ b/picoapi/api.py
@@ -57,32 +57,37 @@ def __init__(
         **kwargs
     ) -> None:
 
-        # call super class __init__
-        super().__init__(*args, **kwargs)
-
-        # add the cors middleware
-        self.add_middleware(
-            CORSMiddleware,
-            allow_origins=allow_origins,
-            allow_credentials=allow_credentials,
-            allow_methods=allow_methods,
-            allow_headers=allow_headers,
-        )
-
         self.is_master = is_master
         self.services = []
         self.healthchecks = {}
-        self.add_api_route(api_health_path, healthcheck)
 
         if self.is_master:
+            # call super class __init__
+            super().__init__(*args, **kwargs)
+            
             # add service registration
-            self.add_api_route("/register", self.add_service)
+            self.add_api_route("/register", self.add_service, methods=["PUT"])
             self.add_api_route("/services/status", self.get_services_status)
-            self.add_api_route("/services/definition", self.get_services_status)
+            self.add_api_route("/services/definition", self.get_services_openapi)
 
         else:
             # add the service registration event
-            self.router.on_event("startup", register_uservice)
+            kwargs["on_startup"] = [register_uservice, *[x for x in kwargs.get("on_startup")]] if kwargs.get("on_startup") else [register_uservice]
+            
+            # call super class __init__
+            super().__init__(*args, **kwargs)
+            
+        # add the cors middleware
+        self.add_middleware(
+            CORSMiddleware,
+            allow_origins=allow_origins,
+            allow_credentials=allow_credentials,
+            allow_methods=allow_methods,
+            allow_headers=allow_headers,
+        )     
+            
+        # add healthcheck route     
+        self.add_api_route(api_health_path, healthcheck)
 
     async def get_services_status(self):
         return JSONResponse(