Database Schema Agent

Instructions

Design or review Prisma data models for Next.js applications.

When to Use

• Use for Prisma schema design/review (relations, indexes, naming).
• Prefer data-layer-handbook first if ORM is undecided.
• Prefer api-handbook for HTTP shapes over the schema.

Mode A - generate schema

1. Parse the user’s plain-English domain model (entities, relationships, enums).
2. Produce schema.prisma with:
   • @@map / @map only if user prefers snake_case tables
   • IDs (cuid() or uuid() - match repo if exists)
   • indexes on foreign keys and frequent filters
3. Include migration commands: pnpm exec prisma migrate dev --name init (or match project scripts).
4. Requires user approval before writing files.

Mode B - audit existing schema

1. Read prisma/schema.prisma and related queries if present.
2. Report: missing indexes, ambiguous relations, cascade risks, N+1-prone includes, naming inconsistencies.
3. Suggest fixes as diffs or bullet list - no writes unless approved.

Outcomes

• Mode A: copy-paste-ready schema + migration instructions.
• Mode B: prioritized audit with severity labels.

Output Rules

State mode. For Mode A, fence schema.prisma only after approval summary.

Scope and boundaries

• In scope: Prisma schema design and review for Node/Next backends. If the team is choosing ORM vs SQL, point to data-layer-handbook and references/data-layer-choice.md first, then return here for Prisma.
• Out of scope: raw SQL production migrations without user review, multi-database sharding, destructive data migrations, Drizzle schema authoring (see data-layer-handbook).

Safety

• Mode A writes schema files - requires_user_approval: true.
• Never embed production database URLs or passwords; use env("DATABASE_URL") only.
• Warn before onDelete: Cascade on high-cardinality relations.

Troubleshooting

• Migrate drift: suggest prisma migrate status before new migrations.
• PlanetScale / serverless: note provider-specific limitations if user names them.
• Monorepo: confirm schema.prisma path (packages/db vs root).

Related skills

• data-layer-handbook - ORM vs SQL choice first
• next-server-patterns - query placement
• api-handbook - API shapes over the schema

GitHub: https://github.com/bh611627/skillcodex/tree/main/skills/database-schema-agent/SKILL.md
npm: https://www.npmjs.com/package/@skillcodex/skills