cross-layer-check

name	cross-layer-check
description	Cross-layer consistency check. Ensures new fields, enums, and types are consistent across all layers: DB → repository → service → DTO → validator → API response → tests.
user-invocable	true

Cross-Layer Check Skill

Purpose

Prevent cross-layer inconsistency — the #1 source of runtime bugs in multi-layer architectures.

Protocol

When a new field, enum value, or type is added:

1. Identify all layers it touches

DB schema → migration → repository → entity/model → service → mapper → DTO → validator → API response → client types → tests

2. Search each layer

For each new field name (e.g., userStatus):

grep -rn 'userStatus\|user_status' --color=never . 2>/dev/null | head -30

3. Verify consistency

Layer	File	Field name	Type	Required?
DB schema	migration/xxx.sql	user_status	VARCHAR(20)	YES
Repository	repo/user.ts	userStatus	string	YES
Service	service/user.ts	userStatus	UserStatus	YES
DTO	dto/user.dto.ts	userStatus	UserStatusEnum	YES
API response	api/user.ts	user_status	string	YES

4. Flag inconsistencies

Any layer that is missing the field or uses a different type → 🔴 Must Fix

Common Failure Patterns

• Field exists in DB but not in DTO → returns undefined to client
• Enum value added in code but not in DB constraint → runtime error
• Field renamed in service but not in tests → false positives
• New field in API response but not in API schema/docs → drift