Skill library / Claude Code

Database Migration skill for Claude Code

Migrations break production when they lock tables or can't be rolled back. This skill makes Claude Code write migrations that are reversible and safe to deploy.

What it's good for

• Prisma, Drizzle, Rails, Django or Alembic projects
• Adding indexes to large tables
• Renaming columns without downtime

How the skill works

1. Detect the migration tool from the repo
2. Generate the migration with up and down steps
3. Flag operations that lock large tables and propose safe alternatives
4. Update models/types to match
5. Run the migration locally and confirm rollback works

Built-in rules

• Never drop columns or tables without explicit confirmation
• Split risky changes into expand/contract steps
• Never edit already-applied migrations

Example

You: “Add a nullable 'referrer' column to users”
Result: A Prisma migration, updated schema, and a note that it's safe online with no backfill needed.

SKILL.md template

Save as database-migration/SKILL.md.

---
name: database-migration
description: "Creates safe, reversible database migrations for schema changes using the project's ORM or migration tool. Use when the user asks to add a column, table, index or change the database schema."
---

# Database Migration

## Workflow
1. Detect the migration tool from the repo
2. Generate the migration with up and down steps
3. Flag operations that lock large tables and propose safe alternatives
4. Update models/types to match
5. Run the migration locally and confirm rollback works

## Rules
- Never drop columns or tables without explicit confirmation
- Split risky changes into expand/contract steps
- Never edit already-applied migrations

How to install in Claude Code

Unzip into .claude/skills/ in your project (or ~/.claude/skills/ for all projects) and invoke it with /skill-name.

Pro tip

Document your production database size in references/ so it can judge locking risk.

FAQ

Related skills

• Code Review skill for Claude Code
• Commit Message skill for Claude Code
• API Documentation skill for Claude Code