Constitution Skill

Purpose

Create or update specs/constitution.md when the team wants shared rules that spec-skills should apply during their own workflow.

Input

• User-provided project rules (via prompt or conversation)
• Existing specs/constitution.md when present

Output

• specs/constitution.md

Steps

1. Determine language.
   • Use the existing specs/constitution.md frontmatter value if present
   • Otherwise infer from the user's own message (never from this SKILL.md or system instructions)
   • If still unknown, ask the user before proceeding
   • Conduct all subsequent interaction in this language
2. Read specs/constitution.md; if missing, initialize from references/constitution-template.md.
3. Keep the document structure aligned with references/constitution-template.md.
   • Do not invent additional top-level sections unless the user explicitly requests them
4. Update Core Principles based on user-provided rules.
   • Ask the user if no rules were provided
   • Keep only stable, project-wide principles here when they are meant to guide spec-skills phases
   • Prefer durable decision principles over implementation details
   • Do not copy concrete coding conventions, framework APIs, directory names, commands, or tool-specific rules into the constitution unless the user explicitly wants to elevate them into permanent governance
   • Even when the user requests elevation, include such a rule only if it is intended to remain valid across features and over time; otherwise keep it in lower-level docs
   • The constitution should govern spec-skills behavior and outputs, not become a general repository policy file by default
   • Apply YAGNI: if a principle is speculative or addresses a scenario that hasn't occurred, omit it. Constitutions grow stale when they accumulate hypothetical rules.
5. Add variable project rules only when the user specifies them.
   • Fold them into existing principles when possible
   • If a rule belongs more naturally in AGENTS.md, contribution docs, or feature documents, keep it out of the constitution and preserve that separation of responsibility explicitly
6. Update frontmatter.
   • Required keys: language, summary
7. If updating an existing constitution, verify consistency with existing feature documents.
   • Check specs/{feature}/spec.md and plan.md
   • Preserve consistency by removing contradictions, not by copying feature-level implementation detail into the constitution
   • Skip this step when no feature documents exist
8. Perform final review and keep the file within 150 lines.
   • Remove repetition
   • Simplify wording
   • Resolve contradictions
9. In the completion message, suggest the next step.
   • New feature: spec-specify
   • Existing feature update: spec-specify for the target spec.md

Success Criteria

• Constitution reflects the shared rules that spec-skills should use during the workflow.
• Constitution stays at the level of durable governing principles rather than duplicating lower-level implementation guidance.
• Frontmatter values are valid and complete.
• Related feature documents stay consistent.

Completion Guidance

• Next recommended step: spec-specify
• Include the target feature and next file path in the response