Policies over facts

A Dialect establishes architecture. A Policy asks whether that architecture satisfies an authored assertion. It does not inspect raw Terraform attributes, repair interpretation, or contact a provider.

The subnet example asks whether an interpreted subnet has network Context:

policies/subnet-network-context.rf.hcl RF

policy "subnet-network-context" {
  target {
    concept = rf.concept.subnet
  }

  assert = exists(contexts(rf.context.network, rf.concept.virtual-network))
  message = "Subnets must have an established virtual network context."
}

This Policy belongs to the source root containing its policy_pack manifest. target selects instances by Concept, applied Rule or both; an owner filter can narrow that selection. It does not select arbitrary raw resource types. Possible target interpretations that remain unsettled are retained as uncertain evaluations. Policy target selection defines the coverage behavior.

Query the claim you intend

contexts and relations query direct outgoing facts on the selected instance. contributions queries incoming contributions from a specified contributor. For example, a bucket Policy asks about its incoming versioning Contribution. Queries do not follow placement or Relations transitively.

A query target filter names the emission's exact to contract. A Concept and a Rule are not interchangeable filters merely because one instance carries both. Built-ins defines all five functions.

Presence and absence need different proof

One confirmed fact makes exists true even when another endpoint remains unresolved. Zero facts make it false only when the query is supported and its relevant closures and population are complete. Missing emission coverage or an indeterminate closure makes the empty result unknown. Negating that unknown result cannot prove absence.

length needs complete evidence for an exact count. Some numeric assertions can still be proved from a known lower bound: at least one confirmed fact proves length(...) >= 1, but not length(...) == 1 when more facts remain unresolved.

A known-true assertion passes, known-false violates, and unknown is indeterminate. A Policy with no targets makes no decision. None of these outcomes writes back into the Form. Use Understand Policy outcomes to run the same assertion through pass, violation, uncertainty and zero targets.

Keep the semantic environment fixed

Policy source uses qualified references. Linking resolves them against the Form's recorded semantic identities and produces exact pins. A compiled Pack with different pins is refused, not silently relinked. Policies evaluate a selected architecture stage: normally Planned for a plan and Recorded for a state. A comparison Form evaluates its two selected sides by default.

Continue with Write a Policy Pack. Evaluation owns exact truth tables and exit status.