Sequelize documentation is pretty bad for some of this stuff, but it has the functionality you listed. You can give Postgres a default uuid by setting the column options to ‘new Sequelize.UUIDV4()’, and queryInterface supports add, remove and change column.

The biggest annoyance I had with migrations was anything that needed a model to be defined inside the migration. I eventually gave up on that and just wrote my own scripts to work around it. But perhaps I just wasn’t persistent enough...