diff --git a/api/controllers/openapi/workspaces.py b/api/controllers/openapi/workspaces.py
index 007575460af..55c3f02b289 100644
--- a/api/controllers/openapi/workspaces.py
+++ b/api/controllers/openapi/workspaces.py
@@ -65,7 +65,7 @@ from services.feature_service import FeatureService
 
 def _member_response(account: Account) -> MemberResponse:
     return MemberResponse(
-        id=str(account.id),
+        id=account.id,
         name=account.name,
         email=account.email,
         role=account.role.value if account.role else "",
@@ -205,7 +205,7 @@ class WorkspaceMembersApi(Resource):
     def post(self, ctx: Context, workspace_id: str, *, body: MemberInvitePayload):
         tenant = ctx.workspace
 
-        _check_member_invite_quota(str(tenant.id))
+        _check_member_invite_quota(tenant.id)
 
         try:
             token = RegisterService.invite_new_member(
@@ -235,9 +235,9 @@ class WorkspaceMembersApi(Resource):
         return MemberInviteResponse(
             email=normalized_email,
             role=body.role,
-            member_id=str(member.id),
+            member_id=member.id,
             invite_url=invite_url,
-            tenant_id=str(tenant.id),
+            tenant_id=tenant.id,
         )
 
 
@@ -320,7 +320,7 @@ class WorkspaceMemberApi(Resource):
 
 def _workspace_summary(tenant: Tenant, membership: TenantAccountJoin) -> WorkspaceSummaryResponse:
     return WorkspaceSummaryResponse(
-        id=str(tenant.id),
+        id=tenant.id,
         name=tenant.name,
         role=getattr(membership, "role", ""),
         status=tenant.status,
@@ -330,7 +330,7 @@ def _workspace_summary(tenant: Tenant, membership: TenantAccountJoin) -> Workspa
 
 def _workspace_detail(tenant: Tenant, membership: TenantAccountJoin) -> WorkspaceDetailResponse:
     return WorkspaceDetailResponse(
-        id=str(tenant.id),
+        id=tenant.id,
         name=tenant.name,
         role=getattr(membership, "role", ""),
         status=tenant.status,