migration-gen

name	migration-gen
description	Generates a database migration file for schema changes
argument-hint	<description-of-change>
user-invocable	true
allowed-tools	Read Glob Bash Edit
effort	low

Generate Database Migration

Change: $ARGUMENTS

1. Detect ORM/migration tool:

cat package.json | grep -E '"prisma"|"drizzle"|"typeorm"|"knex"|"sequelize"|"migrate"'
ls prisma/ migrations/ db/migrations/ 2>/dev/null | head -10

2. Read the current schema:

cat prisma/schema.prisma 2>/dev/null || ls migrations/ 2>/dev/null | tail -3 | xargs -I{} cat migrations/{}

3. Generate the migration based on the requested change:

   • Additive changes (new table, new column with default) - safe
   • Destructive changes (drop column, rename) - add warning and suggest renaming strategy
   • Data migrations - separate from schema migrations

4. For Prisma: generate migration name and schema change, then ask to run:

npx prisma migrate dev --name $ARGUMENTS

For raw SQL: generate up/down migration files.

5. Always generate a down migration (rollback).

6. Flag any changes that require a deployment strategy (e.g., add-then-backfill, not rename directly).