coding-be

name	coding-be
description	Use when: implementing backend logic in Next.js App Router, including Database queries (DAL), Zod Schemas (Validations), and Server Actions. Focused on data integrity, cache revalidation, and type-safe contracts. Backend-only skill; not for UI design, CSS, or SEO metadata.

coding-be

Purpose: machine-only concise rules for implementing backend features (Firestore + Storage).

Hard rules:

• Architecture: Validation -> DAL -> Actions.
• Validation: Zod in src/lib/validations/{feature}.schema.ts; export TS types via z.infer.
• DAL: Firestore-only in src/lib/dal/{feature}.dal.ts; no external HTTP calls; pure async functions.
• Actions: src/actions/{feature}.action.ts; use 'use server'; signature export async function <name>(ctx, input).
• Transactions: Actions must open Firestore transactions when multiple writes or metadata are involved.
• Idempotency: create operations require Idempotency-Key; persist in idempotency_keys collection; TTL configurable (default 24h); return IDEMPOTENCY_CONFLICT on duplicate.
• Revalidation: call revalidatePath() for affected FE routes.
• Auth: verify JWT (HS256) using JWT_SECRET; roles: admin / employee / viewer.
• Audit: write audit_logs for every mutation with fields: userId, action, resourceType, resourceId, timestamp, ip, userAgent, before, after, meta.
• Logging: use pino; redact passwordHash and idCardImagePath.
• Error shape: always return { success: boolean }; on failure error: { code:string, message:string, httpStatus:number, details?:object }.
• Error codes mapping: VALIDATION_ERROR=400, AUTH_ERROR=401, FORBIDDEN=403, NOT_FOUND=404, CONFLICT=409, RATE_LIMIT=429, IDEMPOTENCY_CONFLICT=409, STORAGE_ERROR=503, INTERNAL_ERROR=500.
• Storage: Firebase Storage; max upload 40MB; allowed MIME: image/jpeg,image/png,application/pdf.
• TypeScript: strict mode; no any.
• File naming: follow feature.schema.ts, feature.dal.ts, feature.action.ts; use named exports only.

Behavioral rule: produce only code and machine-consumable artifacts that follow these rules. Do not add human-oriented explanations.

Resources: see resources/ and examples/ for minimal templates.