# Backend Models > Design database models with clear naming conventions, appropriate data types, relationships, constraints, and indexing strategies. Use this skill when defining database models, schemas, or entities in ORMs like Prisma, Sequelize, TypeORM, ActiveRecord, Django ORM, Mongoose, or similar; when creating tables with PostgreSQL, MySQL, SQLite, MongoDB, or any database; when establishing model relationships (one-to-one, one-to-many, many-to-many); when adding database constraints (NOT NULL, UNIQUE, foreign keys); when implementing timestamps for auditing and debugging; when choosing appropriate data types for columns; when creating indexes on foreign keys and frequently queried fields; when balancing normalization with query performance; when implementing validation at model and database layers; or when structuring data models for optimal query performance and data integrity. Use when this capability is needed. - Skill: `tomevault-io/backend-models` (Agent Skill, multi-file: 2 files) - Install (CLI): `npx skillmds@latest add tomevault-io/backend-models` - Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/backend-models/raw - Safety review: pending (external: skill-scanner PASS, skillspector PASS) - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: AI & ML - Author: tomevault-io (https://skillmd.com/u/tomevault-io) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/tomevault-io/backend-models --- # Backend Models This Skill provides Claude Code with specific guidance on how to adhere to coding standards as they relate to how it should handle backend models. ## When to use this skill - When defining database models, schemas, or entities with ORMs - When creating database tables with appropriate structure - When establishing model relationships and cascade behaviors - When adding database constraints, indexes, and validations - When implementing timestamps for auditing and debugging - When choosing appropriate data types for database columns - When balancing normalization with query performance needs - When working with Prisma, Sequelize, TypeORM, ActiveRecord, Django, Mongoose, or similar ## Instructions For details, refer to the information provided in this file: [backend models](../../../agent-os/standards/backend/models.md) --- > Converted and distributed by [TomeVault](https://tomevault.io/claim/shynlee04) — claim your Tome and manage your conversions.