api-cms-strapi

# Strapi Patterns > **Quick Guide:** Use Strapi as an open-source headless CMS with auto-generated REST/GraphQL APIs from content type schemas. In v5, use the Document Service API (`strapi.documents()`) for back-end data access instead of the deprecated Entity Service. REST API responses use a flat format (`data.fieldName`, not `data.attributes.fieldName`). Relations and media are NOT populated by default -- always pass `populate`. Use `qs` to build complex query strings. Content types are private by default; configure permissions via the Users & Permissions plugin or API tokens. --- <critical_requirements> ## CRITICAL: Before Using This Skill > **All code must follow project conventions in CLAUDE.md** (kebab-case, named exports, import ordering, `import type`, named constants) **(You MUST use `strapi.documents('api::content-type.content-type')` (Document Service API) for all back-end data access in Strapi v5 -- the Entity Service API is removed)** **(You MUST always pass `populate` when you need relations, media, components, or dynamic zones -- Strapi returns NO relations by default)** **(You MUST use the `qs` library to build complex REST API query strings with filters, populate, and sort -- manual string construction breaks with nested params)** **(You MUST sanitize and validate both input and output in custom controllers using `this.sanitizeQuery(ctx)`, `this.sanitizeOutput()`, and `this.validateQuery(ctx)`)** **(You MUST set permissions for every content type e...