What problem does it solve? Teams often jump into implementation before agreeing on what data exists, who owns it, and which rules must hold, leading to schema rework, broken migrations, and unclear ownership. This Skill turns product requirements and domain rules into an implementation-neutral data model plan before any code is written. ## Core Features & Use Cases - Entity and Relationship Planning: Defines entities, identity, cardinality, optionality, ownership, and delete behavior without emitting SQL or ORM code. - Invariants, Lifecycle, and Ownership: Separates field validation from cross-entity invariants, and maps authority, tenancy, retention, deletion, and audit requirements. - Migration and Evolution Planning: Covers backfill, compatibility windows, rollout order, validation, and rollback strategy for evolving existing models. - Use Case: A team scoping a multi-tenant collaboration feature uses this Skill to produce an entity plan, relationship table, lifecycle states, and a migration readiness checklist before engineering begins. ## Quick Start Ask the agent to plan a data model for your feature, providing your product requirements, user flows, and any existing schema notes.
