A migration that runs in a second on your laptop can lock a production table for minutes, or drop data you meant to keep. This skill checks your SQL migration files before they run and tells you which statements are risky, why, and what to do instead.

It returns BLOCK, REVIEW, or PASS for each migration, with the line, the rule, the reason, and a safer pattern. It covers 14 BLOCK rules and 6 REVIEW rules, including dropped tables and columns, indexes built without CONCURRENTLY, table rewrites, foreign keys and NOT NULL added in one step, and transaction problems. It works with plain SQL files, including SQL generated by Prisma and Supabase migrations, and assumes PostgreSQL 12 or newer.

It is a static check of SQL text: it does not connect to your database, so PASS is not a guarantee.

How to use: This is an agent skill: a folder with a SKILL.md file and Python scripts that an AI coding agent such as Claude Code, Cursor, or Codex CLI can run. Unzip it into your agent's skills folder (for Claude Code: ~/.claude/skills/), then ask your agent to check your code. The scripts also run on their own with Python 3.9 or newer, with nothing to install. They read your files only: no network access, and nothing is sent anywhere.