Constitution Skill for Claude

constitution — the project's non-negotiable principles

*The first rsc-sdd phase. Run once per project, then amend. It writes down the rules every later phase obeys: stack canon, quality bars, conventions. Everything downstream — specify, plan, analyze, implement, verify, review — reads this file as guardrails.*

A constitution is small, durable, and enforceable. It is not a wiki of everything you know about the project (that is what 02-DOCS/wiki/ already is, run by the harness). It is the short list of principles that, if violated, mean the work is wrong regardless of whether it runs. If a rule here cannot be checked or pointed at later, it does not belong here — move it to the stack wiki and link it.

Not this phase: *what to build* → ../specify/SKILL.md; the technical approach for one feature → ../plan/SKILL.md; setting up 01-TOOLS/ + 02-DOCS/ or capturing general project knowledge → harness; concrete stack mechanics (*how* to configure Ruff, pytest, Tailwind tokens) → the relevant stack skill (../fastapi/SKILL.md, ../nextjs/SKILL.md, ../go/SKILL.md, ../postgresdb/SKILL.md, ../flutter/SKILL.md, ../design/SKILL.md, ../secure-coding/SKILL.md). The constitution *names* the bar; the stack skill *enforces* it.

Model tier — heavy (opt-in routing)

This phase's default model tier is heavy — it sets the project's non-negotiables, the highest-leverage decisions in the repo. Routing is off unless models.enabled: true in 02-DOCS/wiki/sdd/config.yaml. When on: resolve this phase's tier (models.overrides wins over models.phases), map it to a model via models.tiers, and apply per ../sdd/references/model-routing.md — announce the switch per the accompaniment dial when it differs from the session model, and dispatch any Task/parallel subagents on that model. Routing off or no profile → honor the session model silently. Never fake a switch a tool can't make; skip routing on a one-line change.

Honor the accompaniment dial first

Before asking anything, read 02-DOCS/wiki/harness/user-profile.md and match its technical_level and accompaniment_level. No profile yet → default to non-technical and ask the two gauging questions, or point the user at init; never assume fluency. The constitution interview adapts:

| Level | How this skill behaves |

|-------|------------------------|

| L0 — cavernícola | Infer almost everything from the codebase and stack wiki. Ask only the 1-2 questions that genuinely change a principle. Draft, show, ratify. |

| L1 — breve | One line of *why* per principle proposed. Ask 3-4 questions max. |

| L2 — explica decisiones | Justify each principle as you propose it; surface trade-offs where a rule constrains the team. |

| L3 — acompañamiento total | Explain what a constitution is and why each section matters, one kind question at a time, before writing anything. Non-technical framing. |

Reconcile before you write (do not duplicate the stack wiki)

The harness may already hold real conventions under 02-DOCS/wiki/stack/* (e.g. nextjs.md, fastapi.md, postgresdb.md). The constitution does not copy them — it ratifies the principle and links the detail. Run this reconciliation pass first:

• Read the Knowledge map — the full index lives in 02-DOCS/wiki/index.md (root CLAUDE.md keeps only a short pointer to it). List every 02-DOCS/wiki/stack/* article that exists.
• Read each stack article. Pull out anything already phrased as a rule (a version pin, a lint config, a test threshold, a naming convention).
• For each existing rule, decide: is it a *project-wide non-negotiable* (→ ratify it as a principle, linking the stack article for detail) or a *local mechanic* (→ leave it in the stack wiki, do not lift it into the constitution)?
• Contradictions are findings, not fixes. If two stack articles disagree, or a stack article contradicts what the user states now, surface it and let the user resolve — never silently pick a winner.

The rule of thumb: the constitution says *"every endpoint is typed and tested to ≥80% line coverage — see wiki/stack/fastapi.md for the pytest setup"*. It does not paste the pytest config.

What a principle must have

Every principle in the constitution is one numbered, testable statement. A vague aspiration is not a principle.

• Imperative and specific. "Code is formatted with the repo's formatter on every commit" — not "we value clean code".
• Checkable. There must be a way for ../analyze/SKILL.md and verify to tell whether it held. Prefer a number, a command, or a named artifact.
• Owned. If enforcement lives in a stack skill or a script, link it.
• Falsifiable in review. A reviewer can point at a diff and say "this violates principle 4".

Weak   — "We care about security."
Strong — "4. No secret is ever committed; secrets load from 01-TOOLS/<provider>/.env
          (gitignored). Enforced by secure-coding + a pre-commit secret scan."

The interview (requirements-first, batched)

Gather what you cannot infer, then draft. Ask in batches sized to the accompaniment level (L0: the 1-2 that matter; L3: one at a time, explained). Cover these dimensions — skip any the stack wiki already answers, and confirm rather than re-ask:

• Stack canon — languages, frameworks, runtime/versions, package manager. What is fixed vs. open?
• Quality bar — formatter/linter (must pass clean?), type checking (strict?), test discipline (TDD? coverage floor? what kind of tests gate a merge?).
• Conventions — naming, directory structure, module boundaries, API/error shapes, commit message format.
• Branching & shipping — branch naming, PR required?, who/what gates a merge, release cadence. (Authorship rule is fixed — see below.)
• Security & privacy floor — secret handling, authn/z baseline, data residency, dependency policy.
• Accessibility & UX floor (if there's a UI) — the minimum bar (e.g. WCAG AA, keyboard-navigable).
• Performance budgets (where they matter) — a named budget, not "should be fast".
• Documentation & knowledge — what must be written down (decisions log, the wiki) and when.

For any significant either/or (e.g. "strict types or gradual?", "squash or merge commits?"), use the harness "siempre 3 opciones" shape where it applies: gather the constraint, present up to 3 honest options with a recommendation matched to the team's level, then ratify the choice and log it.

Fixed principles (always present)

Two principles are inherited from the rsc ecosystem and appear in every constitution unless the user explicitly overrides them:

• Git authorship is the human's. Commits and PRs are authored by the human (Eric, or whoever owns the repo). No Co-Authored-By an AI, no "generated with" footer. Enforced at the ship phase.
• Decisions are logged. Every significant decision is appended to 02-DOCS/wiki/sdd/decisions.md (or the harness decisions.md) with date, options considered, and the why. The constitution itself is the highest-order decision record.

Drafting the constitution

Write 02-DOCS/wiki/sdd/constitution.md from the template in references/constitution-template.md. Keep it short — a readable constitution is 1-2 screens, not a manual. Structure:

• Header — project name, version (v1.0.0), ratified date, last-amended date.
• Principles — numbered, grouped by the dimensions above. Each is one testable statement; link the stack article or script that enforces it.
• The bar (Definition of Done) — the merge checklist every feature must pass. This is what verify runs against.
• Amendment log — append-only; every change recorded (see protocol below).

Create 02-DOCS/wiki/sdd/ if it does not exist. Do not overwrite an existing constitution — amend it.

Versioning & amendment protocol

The constitution is versioned so analyze and review can cite "constitution v1.2.0, principle 4".

• Semantic-ish versioning. MAJOR when a principle is removed or reversed (breaks existing work); MINOR when a principle is added or materially tightened; PATCH for wording/clarity with no behavior change.
• Amendments are append-only in the log. Never silently edit a ratified principle — strike it (mark superseded) and add the new one, bump the version, and record date + why in the amendment log.
• Ratification. A new or amended constitution is shown to the user and ratified explicitly before it takes effect. At L0, "ratify" is a quick yes; at L3, walk each change.
• Downstream notice. When a principle changes mid-project, flag that existing specs/plans may now be inconsistent — analyze will catch the drift on the next run.

Anti-patterns

| Anti-pattern | Why it fails / fix |

|--------------|--------------------|

| "I'll write a thorough constitution covering everything about the project." | That's the wiki, not the constitution. Keep only enforceable non-negotiables; link the rest. |

| "This stack detail is important, I'll paste the lint config in here." | No. Ratify the principle, link wiki/stack/* for the mechanic. The constitution names the bar; the stack skill enforces it. |

| "Two stack articles disagree — I'll just pick the stricter one." | Contradictions are findings. Surface them; the user resolves. |

| "The principle is 'write good code' — everyone knows what that means." | Not checkable, not a principle. Make it testable or drop it. |

| "I'll rewrite the existing constitution to match what they said today." | Amend, don't overwrite. Strike + add + bump version + log the why. |

| "No profile yet, I'll assume they're technical and skip the dial." | Default non-technical; ask the two gauging questions or send them to init. |

| "I'll add a Co-Authored-By so the commit credits the assist." | No. Git authorship is the human's — it's a fixed principle, enforced at ship. |

| "I'll ratify it myself since it's obvious." | The user ratifies. Show the draft, get the explicit yes, then it takes effect. |

Checklist before handing off

• [ ] 02-DOCS/wiki/harness/user-profile.md read; verbosity matched to the dial (or gauging questions asked).
• [ ] Reconciliation pass done against every 02-DOCS/wiki/stack/* article; contradictions surfaced, not auto-resolved.
• [ ] Every principle is numbered, imperative, testable, and links its enforcer where one exists.
• [ ] The Definition-of-Done checklist is present (what verify runs against).
• [ ] Fixed principles included: human git authorship + decisions logged.
• [ ] 02-DOCS/wiki/sdd/constitution.md written with version + ratified date + amendment log.
• [ ] Root CLAUDE.md ## Knowledge map pointer has the read-first row for the constitution.
• [ ] The constitution was shown to the user and explicitly ratified.

Project grounding (02-DOCS + CLAUDE.md)

This skill's 02-DOCS record is the constitution at 02-DOCS/wiki/sdd/constitution.md. It is a read-first pointer entry, so its row stays in the short ## Knowledge map pointer in the root CLAUDE.md (create CLAUDE.md if absent, additive only — never delete existing sections) — unlike other sdd artifacts, which are indexed in 02-DOCS/wiki/index.md (the full Knowledge map that root CLAUDE.md points to). Add this row to the root pointer if it is not already present:

| Project constitution (SDD non-negotiables) | `02-DOCS/wiki/sdd/constitution.md` |

Every later rsc-sdd phase reads this file before it works. The harness maintains and improves the article over the life of the project; this skill is the place that ratifies and amends it.

Result envelope

End with the parseable block every SDD phase shares, so the dispatcher can chain without

interpreting prose (contract: ../sdd/SKILL.md):

{
  "status": "complete|blocked|failed",
  "executive_summary": "Constitution written with N numbered, testable rules the later phases inherit.",
  "artifact": "02-DOCS/wiki/sdd/constitution.md",
  "next_recommended": "specify",
  "risk": "low|medium|high",
  "skill_resolution": {
    "used": ["constitution"],
    "missing": [],
    "fallback": [],
    "compact_rules": ["Principles are inherited constraints, not choices to re-make.", "Every rule is testable or it is a preference."]
  },
  "evidence": ["constitution path exists", "rules numbered and testable", "decisions log appended"]
}

Next in the chain

The constitution is the guardrail; now describe what to build. Hand off to ../specify/SKILL.md — turn a fuzzy intent into a spec (what & why, no implementation), grounded in these principles. The full chain: constitution → specify → clarify → plan → tasks → analyze → implement → verify → review → ship (with debug, worktrees, parallel callable on demand). The dispatcher is ../sdd/SKILL.md.