Migrations

Planning a migration

When you change schema.ts, Tessera compares it with the target environment and plans the SQL needed to get there. You always see the plan before anything runs.

npx tessera migrate plan --env staging

Applying a migration

1. Open a pull request with your schema change.

2. CI runs tessera migrate plan and posts the plan as a comment.

3. After merge, run tessera migrate apply --env production or let the deploy hook do it.

Zero-downtime changes

Tessera splits risky changes into safe steps. Adding a notNull column, for example, is applied as add-nullable, backfill, then add the constraint.