Claude Skills

The fcd-* skill family encodes Fractal Co-Design into Claude Code as user-invocable slash commands. Each skill is single-purpose and aligned to one stage of the FCD lifecycle. Together they let an agent (or a human-in-the-loop) walk a problem from spec to merged-ready PR while keeping FCA structure and ECD process discipline intact.

Install

The @fractal-co-design/skills CLI installer is in progress for v0.1. Until it ships, install manually:

git clone https://github.com/VledicFranco/fractal-co-design.git
cp -r fractal-co-design/skills/fca ~/.claude/skills/
cp -r fractal-co-design/skills/fcd-* ~/.claude/skills/

The skills become available as slash commands in Claude Code: /fca, /fcd-ref, /fcd-card, /fcd-design, /fcd-plan, /fcd-surface, /fcd-commission, /fcd-debate, /fcd-review.

The family

The skills sit in two tiers — the foundation (fca, fcd-ref) and the lifecycle (everything else). Lifecycle skills depend on the foundation: load fcd-ref first if you want the agent to behave with FCD discipline across a session.

Skill	Lifecycle	Purpose
fca	reference	Pure FCA expertise — architecture review, domain decomposition, layer questions.
fcd-ref	reference	Foundation — combined FCA + ECD discipline. Load this before any lifecycle skill.
fcd-card	specify	Lightest spec — a 5-question layer stack card in 20 minutes.
fcd-design	specify	Full PRD with surface-first architecture: domains → surfaces → architecture → phases.
fcd-plan	plan	Decompose a PRD into FCA-partitioned commissions with mandatory Wave 0 (surfaces).
fcd-surface	define	Co-design and freeze a port interface between two domains.
fcd-commission	execute	Implement against frozen ports, with a port-freeze pre-check gate.
fcd-debate	decide	Multi-character expert council for adversarial debate, with a mandatory Surface Advocate.
fcd-review	review	Adversarial quality review — port compliance first, internal architecture second.

How they fit together

A typical FCD session walks the lifecycle in order:

1. Specify — fcd-card for a quick layer stack, or fcd-design for a full PRD.
2. Plan — fcd-plan decomposes the PRD into commissions with Wave 0 (surfaces) first.
3. Define — fcd-surface co-designs each shared port and freezes the contract.
4. Decide — fcd-debate resolves any non-trivial design choices with adversarial debate.
5. Execute — fcd-commission implements one slice, gated by the port-freeze pre-check.
6. Review — fcd-review runs the port-priority adversarial review on the work.

You don’t have to use every skill on every problem. The discipline is: if a surface is involved, co-design it before either side implements. The skills enforce that discipline.