# Backend Design: ECR-024 Banner

| ID | BD-2026-024 |
| Status | Approved |
| Coding | Loop authorized |
| Level | L2 |
| Migration | YES 000025 |

## Backend Change Boundary

```text
Domain: Banner (read)
App: AdminHandler → admin.Service → AdminRepo
API: GET /admin/cms/banners; GET /admin/cms/banners/{id}
Permission: admin.cms.read
Migration: 000025
```

## Out of boundary

Banner 写发布 · FeedSlot · ScheduledPublication · UGC · 真支付

Rollback: down migration + remove routes/UI