| name | Next.js Data Access Layer |
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| description | Secure, reusable data access patterns with DTOs and Taint checks. |
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| metadata | {"labels": ["nextjs", "dal", "architecture", "security"], "triggers": {"files": ["**/lib/data.ts", "**/services/*.ts", "**/dal/**"], "keywords": ["DAL", "Data Access Layer", "server-only", "DTO"]}} |
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Data Access Layer (DAL)
Priority: P1 (HIGH)
Centralize all data access (Database & External APIs) to ensure consistent security, authorization, and caching.
Principles
- Server-Only: Must include
import 'server-only' to prevent Client bundling.
- Auth Co-location: Auth checks (
session.role) must be inside the DAL function.
- DTO Transformation: Return plain objects (DTOs), never raw ORM instances.
- No Internal Fetch: Call DAL functions directly. Do not
fetch('localhost/api').
Implementation
| Approach |
When to use |
Reference |
| API Gateway (BFF) |
Enterprise apps with separated Backend (NestJS). |
Pattern A |
| Direct DB |
Fullstack apps or Admin Panels. |
Pattern B |
Limitations
- Client Components: Cannot import DAL files. Must use Server Actions or Route Handlers as bridges.