# Session Materials

- [6. REST Principles](/course-content/backend/node/week2/session-materials/rest-principles-snippets.md)
- [7. OpenAPI Basics](/course-content/backend/node/week2/session-materials/openapi-basics.md)
- [8. Validation and error models](/course-content/backend/node/week2/session-materials/validation-and-error-models.md)
- [9. Knex security](/course-content/backend/node/week2/session-materials/knex-security-snippets.md)