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Fractal Co-Design

fcd-ref

Trigger: load this before any other fcd-* skill, or whenever you want the agent to behave with full FCD discipline across a session.

fcd-ref is the foundation. It combines FCA (structure) and ECD (process) into a single behavioral discipline: port-first temporal ordering, composition-theorem priority, surface-before-architecture sequencing.

When to use

Load /fcd-ref at the start of any session where you want the agent to think in FCD — not just answer FCD questions, but actually reorder its work to match the discipline. Every other fcd-* lifecycle skill assumes fcd-ref is already loaded; running them without it produces work that is FCA-shaped but not ECD-disciplined.

What it changes

When loaded, the skill modifies how the agent approaches design and implementation work:

  • Port-first temporal discipline — surfaces are co-designed and frozen before either side implements. The agent will refuse to write implementation code against an undefined or unfrozen port.
  • Composition theorem priority — when in doubt, the agent prefers the option that preserves composability across surfaces over the option that is locally simpler.
  • Surface-before-architecture ordering — domains are identified first, surfaces are co-designed second, internal architecture is constrained by the frozen surfaces.

Canon reference: ECD — Extreme Co-Design and ECD — FCA Synthesis.