» The Built-In terraform Provider

Terraform includes one built-in data source: terraform_remote_state, which provides access to root module outputs from some other Terraform configuration.

This data source is implemented by a built-in provider, whose source address is terraform.io/builtin/terraform. You do not need to require or configure this provider in order to use the terraform_remote_state data source; it is always available.

The terraform_remote_state data source is documented in the Terraform Language docs.