diff --git a/atroposlib/api/server.py b/atroposlib/api/server.py
index 8cda4abd..0aa1c70f 100644
--- a/atroposlib/api/server.py
+++ b/atroposlib/api/server.py
@@ -100,6 +100,15 @@ async def register(registration: Registration):
 
 @app.post("/register-env")
 async def register_env_url(register_env: RegisterEnv):
+    try:
+        if not app.state.started:
+            return {
+                "status": "wait for trainer to start",
+            }
+    except AttributeError:
+        return {
+            "status": "wait for trainer to start",
+        }
     try:
         isinstance(app.state.envs, list)
     except AttributeError: