Docker Build Cloud: Add automatic top-up / usage-based billing with spend cap for build minutes

[bmdockersupport]

Tell us about your request
Submitting on behalf of a customer: Add an option for Docker Build Cloud build minutes to support either (a) automatic top-up (auto-reload) when minutes are low/empty and/or (b) standard usage-based billing for overage minutes, ideally with a configurable monthly spend cap/limit and notifications.

Which service(s) is this request for?
Docker Build Cloud

Tell us about the problem you're trying to solve. What are you trying to do, and why is it hard?
A customer (startup) is using Docker Build Cloud for CI builds and finds the current prepaid top-up model operationally disruptive. They don’t know their exact monthly minute needs and don’t want to buy a large amount of minutes upfront “just in case.” They want to set a monthly cap (either $/month or minutes) and have builds continue automatically up to that cap. Manual top-ups create ongoing administrative overhead and risk CI disruption when minutes run out.

Are you currently working around the issue?
Customer workaround today is manual monitoring of consumption and purchasing prepaid minutes when low.

Additional context
Docker Build Cloud minutes are documented as included monthly minutes plus prepaid minute buckets for additional minutes (no auto top-up mentioned):
https://docs.docker.com/subscription/scale/

Customer feedback: competitors offer standard usage-based billing, and the absence of auto top-up/spend cap is a major impediment to adopting Build Cloud for CI at a startup.