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Rule model

Defines how preset AI expresses, evaluates, and evolves enforceable system rules.

Why this exists

Rules are preset AI's enforcement layer. They convert design-system intent into machine-evaluable constraints for:

  • product workflows
  • CI and CLI checks
  • MCP read/write governance

Rule shape

At minimum, a rule encodes:

  • intent: the behavior or outcome it governs
  • predicate: the condition to evaluate
  • severity: impact level when violated
  • scope: where it applies (artifact, route, workspace, org)
  • guidance / fix: how to remediate

Rule categories

Common categories:

  • token usage and naming
  • preset usage and prop constraints
  • pattern composition rules
  • interaction and accessibility requirements
  • AI generation and write constraints

Severity model

Use consistent severity semantics:

  • info: informational, no action required
  • warning: should fix, doesn't block
  • error: should fix, signals real problem
  • blocking: policy-gated, must fix before merge or apply

Severity is mode-aware. Same rule, different teeth depending on whether you're in Observe, Assist, Guard, or Enforce.

Evaluation lifecycle

Rules can be evaluated at multiple points:

  • pre-generation: AI constraints
  • post-generation: validate output
  • pre-apply: proposal gate
  • CI / PR checks
  • periodic health and audit scans

Rule evolution

Rules should evolve with system maturity:

  • start descriptive (guidance-heavy)
  • graduate to stricter enforcement when confidence is high
  • track exception volume and false-positive rates
  • sunset or split brittle rules

Exceptions and overrides

Exceptions should be:

  • explicit
  • time-bounded
  • owner-attributed
  • auditable

Overrides should never silently disable baseline governance. See Exceptions and escalation for the full lifecycle.

Rule outputs

Every evaluation should produce machine- and human-usable output:

  • pass / fail result
  • severity and scope
  • violation location and context
  • recommended fix path

Rule quality criteria

A good rule is:

  • unambiguous: one interpretation, no edge cases the author meant differently
  • testable: outcome can be verified deterministically
  • scoped: applies only where intended
  • explainable: the violation message tells the reader what to do
  • stable: doesn't flag false positives in typical development workflows

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Last reviewed by @jschuyler
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