google-cloud-billing-budgets-v1beta1

https://github.com/googleapis/google-cloud-ruby

The Cloud Billing Budget API stores Cloud Billing budgets, which define a budget plan and the rules to execute as spend is tracked against that plan. Note that google-cloud-billing-budgets-v1beta1 is a version-specific client library. For most uses, we recommend installing the main client library google-cloud-billing-budgets instead. See the readme for more details.