| name | Constitution Format |
| description | Knowledge about writing effective project constitution files for LLM/coding agents. Use this skill when creating, editing, or reviewing constitution.md files. |
| version | 0.1.0 |
Constitution Format Knowledge
Purpose
A constitution file defines rules, best practices, patterns, and guardrails for LLM and coding agents working in a project. Unlike human documentation, constitutions are optimized for token efficiency and machine parsing.
File Location
Standard locations (checked in order):
constitution.md (project root)doc/constitution.md
Token Budget
Hard limit: 25,000 tokens
Approximate conversion: 1 token ≈ 4 characters
Monitor size when adding rules. A well-written constitution for a medium project typically uses 5,000-15,000 tokens.
Structure
# Project Constitution
Brief one-line project description.
## <Category 1>
- Rule 1
- Rule 2 (rationale)
## <Category 2>
- Rule 3
- Prefer X over Y
- Avoid Z
Common Categories
| Category | Contents |
|---|
| Stack | Languages, frameworks, versions |
| Patterns | Required architectural patterns |
| Anti-patterns | What to avoid |
| Conventions | Naming, structure, organization |
| Testing | Testing requirements and approaches |
| Security | Security requirements |
| Performance | Performance constraints |
| Dependencies | Dependency rules |
Writing Effective Rules
DO
- Imperative voice: "Use X" not "You should use X"
- Be specific: "Use
const by default" not "Prefer immutability"
- Include brief rationale: "Avoid any (breaks type safety)"
- Quantify when possible: "Max 300 lines per file"
- State the positive: "Use async/await" not "Don't use callbacks"
DON'T
- Write explanatory prose
- Include code examples (unless critical)
- Duplicate information
- Use filler words (very, really, always try to)
- Over-qualify (usually, in most cases, generally)
Rule Formats
Simple rule:
- Use TypeScript strict mode
Rule with rationale:
- Use TypeScript strict mode (catches null errors early)
Preference:
- Prefer composition over inheritance
Prohibition:
- Avoid `any` type
Conditional:
- Use server components by default; client components only for interactivity
Exception:
- Use strict mode (except legacy/ directory)
Quantified:
- Max 300 lines per file
- Min 80% test coverage for business logic
Example Constitution
# Project Constitution
TypeScript monorepo for e-commerce platform.
## Stack
- TypeScript 5.3+ strict mode
- React 18 with Server Components
- Next.js 14 App Router
- PostgreSQL with Drizzle ORM
- Vitest for testing
## Patterns
- Feature-based directory structure
- Repository pattern for data access
- Use server components by default
- Client components only for interactivity
- Collocate tests with source files
## Anti-patterns
- Avoid `any` type (use `unknown` if needed)
- No barrel exports in feature modules
- No circular dependencies
- Avoid prop drilling beyond 2 levels
## Conventions
- camelCase for functions/variables
- PascalCase for components/types
- kebab-case for files and directories
- Prefix interfaces with I (IUser, IProduct)
- Suffix types with Type only if needed for clarity
## Testing
- Unit tests for business logic (min 80% coverage)
- Integration tests for API routes
- E2E tests for critical user flows
- Use Testing Library, avoid implementation details
## Security
- Validate all user input at API boundary
- Use parameterized queries only
- No secrets in code or logs
- HTTPS only, secure cookies
Maintenance
- Review constitution when adding major features
- Remove rules for deprecated technologies
- Consolidate overlapping rules periodically
- Keep total under 25,000 tokens
