# Implementer — F-009 Brands module

done -> work/artifacts/F-009/implementer.md

## Summary
Implemented brands as an independent backend module with slug URLs and SEO metadata, added product-brand assignment to catalog, and extended public product search with a brand filter.

## Changed files
- `project/src/modules/brands/domain/brand.ts`
- `project/src/modules/brands/domain/errors.ts`
- `project/src/modules/brands/domain/ports.ts`
- `project/src/modules/brands/application/brand-use-cases.ts`
- `project/src/modules/brands/infrastructure/pg-brand-repository.ts`
- `project/src/modules/brands/api/brands.routes.ts`
- `project/src/modules/brands/index.ts`
- `project/migrations/007_brands.js`
- `project/src/modules/catalog/domain/product.ts`
- `project/src/modules/catalog/domain/errors.ts`
- `project/src/modules/catalog/domain/ports.ts`
- `project/src/modules/catalog/application/product-use-cases.ts`
- `project/src/modules/catalog/infrastructure/pg-product-repository.ts`
- `project/src/modules/catalog/api/catalog.routes.ts`
- `project/src/app/build-app.ts`
- `project/src/app/tests/brands.itest.ts`
- `project/src/app/tests/catalog.itest.ts`
- `work/artifacts/F-009/architect.md`
- `backlog/features.json`
- `work/current.md`

## Acceptance traceability
1. Duplicate brand slug returns HTTP 409
   - Implemented through `brands_brands.slug UNIQUE` and `BRAND_SLUG_EXISTS` mapping.
   - Covered by `project/src/app/tests/brands.itest.ts`.
2. Products list filterable by brand
   - `GET /products/search?brandSlug=<slug>` filters active products by stored `catalog_products.brand_id` joined to `brands_brands.slug`.
   - Covered by `project/src/app/tests/catalog.itest.ts`.
3. Public URL is `/marca/<slug>`
   - Implemented `GET /marca/:slug` and serialized `url: /marca/<slug>`.
   - Covered by `project/src/app/tests/brands.itest.ts`.
4. `verify.sh` green
   - Verified after implementation.

## Commands run
- `cd project && npm run typecheck` — PASS
- `cd project && npm test` — PASS: 59 passed, 31 skipped (DB integration skipped without `TEST_DATABASE_URL`)
- `cd project && npm run lint` — PASS after Prettier normalization
- `cd project && npm run build` — PASS
- `cd project && npm run lint:boundaries` — PASS: 79 files checked
- `./scripts/verify.sh` — PASS

## Notes
- No new npm dependencies.
- Brand mutation routes are admin-only via shared auth injected from the composition root.
- Public brand reads are unauthenticated.
- Catalog references `brands_brands` only at repository/SQL boundary; it does not import brands module internals.
- Documentation stage should update README/API notes because new user-facing brand endpoints, product brand assignment, and product error code were added.
