diff --git a/skyline_apiserver/api/v1/login.py b/skyline_apiserver/api/v1/login.py
index e4d5941..8b1cc80 100644
--- a/skyline_apiserver/api/v1/login.py
+++ b/skyline_apiserver/api/v1/login.py
@@ -173,9 +173,10 @@ async def login(
         regex=constants.INBOUND_HEADER_REGEX,
     ),
 ) -> schemas.Profile:
+    region = credential.region or CONF.openstack.default_region
     try:
         project_scope, unscope_token, default_project_id = await _get_projects_and_unscope_token(
-            region=credential.region,
+            region=region,
             domain=credential.domain,
             username=credential.username,
             password=credential.password,
@@ -186,13 +187,13 @@ async def login(
             default_project_id = None
         project_scope_token = await get_project_scope_token(
             keystone_token=unscope_token,
-            region=credential.region,
+            region=region,
             project_id=default_project_id or project_scope[0].id,
         )
 
         profile = await generate_profile(
             keystone_token=project_scope_token,
-            region=credential.region,
+            region=region,
         )
 
         profile = await _patch_profile(profile, x_openstack_request_id)
diff --git a/skyline_apiserver/schemas/login.py b/skyline_apiserver/schemas/login.py
index 1b193a6..9c80b9a 100644
--- a/skyline_apiserver/schemas/login.py
+++ b/skyline_apiserver/schemas/login.py
@@ -24,7 +24,7 @@ from skyline_apiserver.types import constants
 
 
 class Credential(BaseModel):
-    region: str = Field(..., description="Credential user region")
+    region: Optional[str] = Field(None, description="Credential identity service region")
     domain: str = Field(..., description="Credential user domain")
     username: str = Field(..., description="Credential username")
     password: str = Field(..., description="Credential password for user")
diff --git a/swagger.json b/swagger.json
index de89e87..4f07a65 100644
--- a/swagger.json
+++ b/swagger.json
@@ -2229,7 +2229,6 @@
             "Credential": {
                 "title": "Credential",
                 "required": [
-                    "region",
                     "domain",
                     "username",
                     "password"
@@ -2239,7 +2238,7 @@
                     "region": {
                         "title": "Region",
                         "type": "string",
-                        "description": "Credential user region"
+                        "description": "Credential identity service region"
                     },
                     "domain": {
                         "title": "Domain",
diff --git a/tox.ini b/tox.ini
index e58c8ff..d85bffe 100644
--- a/tox.ini
+++ b/tox.ini
@@ -106,6 +106,7 @@ commands =
 description =
   Generate swagger files.
 envdir = {toxworkdir}/shared
+allowlist_externals = skyline-swagger-generator
 commands =
   skyline-swagger-generator -o swagger.json
 
@@ -113,6 +114,7 @@ commands =
 description =
   Generate config files.
 envdir = {toxworkdir}/shared
+allowlist_externals = skyline-sample-config-generator
 commands =
   skyline-sample-config-generator -o etc/skyline.yaml.sample