diff --git a/tests/api.py b/tests/api.py
index 338e043..d9d1738 100644
--- a/tests/api.py
+++ b/tests/api.py
@@ -21,7 +21,7 @@ class User():
     name: string
     password: string
 
-    def __init__(self, email, password, name, token = ""):
+    def __init__(self, email, password, name, id="", token = ""):
         self.email = email
         self.password = password
         self.name = name
@@ -32,45 +32,49 @@ class BackendApi():
     def __init__(self, httpClient):
         self.httpClient = httpClient
 
-    def user_create(self) -> User:
-        email = ''.join(random.choices(string.ascii_lowercase + string.digits, k=10)) + '@test.test'
-        name = ''.join(random.choices(string.ascii_letters, k=10))
-        password = 'Abcdef1!!1'
-    
-        response = self.httpClient.post(
-            "/v1/user/create",
-            json={
-                "email": email,
-                "password": password,
-                "name": name,
-            },
-        )
-        if response.status_code != 200:
-            raise AssertionError('can not create user')
+    def parse_response(self, response):
+        if response.status != 200:
+            raise AssertionError('something wrong')
         
-        return User(email, password, name)
+        json = response.json()
+        if json['status'] == 'success':
+            if 'result' in json:
+                return json['result']
+            return None
+        
+        error = json['error']
+        raise AssertionError(error['id'], error['message'])
+
+    def user_create(self, user: User | None) -> User:
+        if user == None:
+            email = ''.join(random.choices(string.ascii_lowercase + string.digits, k=10)) + '@test.test'
+            name = ''.join(random.choices(string.ascii_letters, k=10))
+            password = 'Abcdef1!!1'
+            user = User(email, password, name)
+    
+        res = self.parse_response(
+            self.httpClient.post(
+                "/v1/user/create", json={
+                    "email": user.email,
+                    "password": user.password,
+                    "name": user.name,
+                }
+            )
+        )
+
+        return User(res['email'], res['password'], res['name'], res['id'])
         
     def user_login(self, user: User) -> Auth:        
-        response = self.httpClient.post(
-            "/v1/user/login", 
-            json={
-                "email": user.email+"a",
-                "password": user.password,
-            },
+        res = self.parse_response(
+            self.httpClient.post(
+                "/v1/user/login", json={
+                    "email": user.email+"a",
+                    "password": user.password,
+                },
+            )
         )
-
-        status = response.json()['status']
-        if status == 'error':
-            raise AssertionError(response.json()['error']['message'])
-
-        if response.status_code != 200:
-            raise AssertionError('can not login user')
-
-        token = response.json()['result']['token']
-        if token == '':
-            raise AssertionError('empty user token')
         
-        return Auth(token)        
+        return Auth(res['status'])        
 
     def dummy_get(self, auth: Auth):
         headers = {"X-Auth": auth.token}