# Backend Design: ECR-023 KnowledgeSource

| ID | BD-2026-023 |
| Status | Approved |
| Coding | Loop authorized |
| Level | L2 |
| Migration | YES 000024 |

## Backend Change Boundary

```text
Domain: KnowledgeSource (read catalog only)
App: AdminHandler → admin.Service → AdminRepo
API: GET /admin/ai/knowledge-sources[+/:id]
Permission: admin.ai_config.read (reuse; no new perm)
Migration: 000024 knowledge_sources + seed ask_grounding
UI: admin-h5 /ai KnowledgeSource panel
```

## Out of boundary

KnowledgeChunk · Embedding · upload/publish · ToolDefinition · UGC · Payment · runtime RAG wiring

Rollback: down migration + remove routes/UI panel