How to get the ID of an inserted or updated record in Sequelize upsert?

I don’t think that returning the upserted record was available when the OP asked this question, but it has since been implemented with this PR. As of Sequelize v4.32.1, you can pass a boolean returning as a query param to select between returning an array with the record and a boolean, or just a boolean indicating whether or not a new record was created.

You do still need to provide the id of the record you want to upsert or a new record will be created.

For example:

const [record, created] = await Model.upsert(
  { id: 1, name: 'foo' }, // Record to upsert
  { returning: true }     // Return upserted record
);