I start from a brand new root account and I want to reference the root account in my pulumi program:

export const rootAccount = new aws.organizations.Account(INFRA_CONFIG.REFERENCE_ACCOUNT_NAME, {
  email: INFRA_CONFIG.ROOT_ACCOUNT_EMAIL,
  iamUserAccessToBilling: 'ALLOW',
  parentId: rootOrgUnit.id
});

is it possible to do that? Pulumi error because this user already exist

This blog post on adopting existing resources may be helpful to you https://www.pulumi.com/blog/adopting-existing-cloud-resources-into-pulumi/

Note that if you want to just reference an existing resource, instead of to adopt and manage an existing resource, you can just use

aws.organizations.Account.get

.

thanks to both of you, { import } is so clean