Write safe, reversible database migrations for this repo's conventions. Use for any schema change.
Installation
Installer avec Codex ou Claude Copiez ce prompt, collez-le dans Codex, Claude ou un autre assistant, puis laissez-le vérifier la page du skill et l'installer pour vous.
Write safe, reversible database migrations for this repo's conventions. Use for any schema change.
when_to_use
add/alter a table, column, index, or constraint
targets
["*"]
Migration Writer
Read the current schema first. Match the repo's migration tool and naming (NNN_<verb>_<noun>).
Write BOTH up and down. A migration you can't reverse is a migration you can't deploy safely.
Live-safe: on a hot table, adding a NOT NULL column with no default, or an index without CONCURRENTLY, takes a blocking lock. Split into steps: add nullable → backfill → add constraint.
Backfill large tables in batches, not one statement.
Never edit an already-merged migration - add a new one.
Test with a dry-run before committing. Output the migration + the exact deploy order.