A project does not need everything. It may need only a Helm chart, or only Ansible roles and playbooks, or only a Terraform foundation. This directory shows the six cases, and what tells them apart is the user's choice — nothing else.

forge generate -s examples/helm-only.yml -o /tmp/storefront

Three ways, and they combine:

1. An absent section generates nothing. That is the basic mechanism, with no exception. ansible-only.yml contains no helm: section: no chart is produced. There is no option to pass, no flag to turn off.

2. --only restricts one run. On a project declaring two domains, to regenerate just one of them:

forge generate -s examples/foundation-and-chart.yml -o /tmp/inventory --only helm

--only always restricts, it never adds: asking for a domain the specification does not declare will not make it appear.

3. The interview asks which ones to produce. forge new asks the question before writing anything, and then only asks about the domains you kept.

forge new -o /tmp/my-service

forge plugins -s examples/helm-only.yml

says, for that specification, which domains are requested and which are not. And forge generate --dry-run announces what it would produce without writing anything.

If a specification declares no domain, forge does not silently produce an empty project: it says which ones are available and how to ask for one.

The pipeline domain is the only one whose output depends on the other sections. It emits one validation job per declared domain, with the commands each domain announces itself and the installation of the tools they require.

Add a helm: section to pipeline-only.yml and a "Validate Helm" job appears, without a single template line changing. It invents nothing for all that: a domain that does not say how to deploy itself is named in the emitted file, not guessed.

It is also the only domain whose output is the repository root — a CI file only exists where its tool reads it.

Add its section to forge.yml, then:

forge generate --only terraform

The already generated domains are left untouched. Conversely, removing a section erases nothing: forge has never deleted a file you may have edited — forge diff shows you the difference, the deletion stays yours.

tests/test_domain_selection.py generates each of these files and checks that it produces exactly the domains it declares, no more and no less. It also checks that a single-domain example exists for every shipped domain: a domain added without one makes the suite fail. A stale example is not possible here.