Constitution (Project Charter)

A guide for writing a Constitution that defines your project's core principles.

What is a Constitution?

A Constitution is a document that defines your project's core principles, technical decisions, and forbidden practices. All specs and implementations must follow the Constitution.

Structure

# [Project Name] Constitution

## Metadata

- **Version**: 1.0.0
- **Last Modified**: 2025-12-24

## Core Principles

Fundamental values and direction of the project

## Technical Principles

Technical decisions and standards

## Forbidden

Things that must never be done

Writing Each Section

Core Principles

The fundamental values of the project:

## Core Principles

1. **User First**: User experience is the basis of all decisions
2. **Data Protection**: User data safety is the top priority
3. **Simplicity**: Simple is better than complex
4. **Transparency**: System behavior should be predictable

Technical Principles

Technical decisions and standards:

## Technical Principles

### Languages and Frameworks
- Use TypeScript strict mode
- Use React 18+
- Support Node.js 20+

### Code Style
- Apply ESLint + Prettier
- Type definitions required for all functions
- Comments explain "why"

### Testing
- Maintain test coverage above 80%
- E2E tests only for core flows

Forbidden

Things that must never be done:

## Forbidden

### Code
- `any` type usage
- console.log in production code
- Hardcoded secrets

### Dependencies
- moment.js (alternative: date-fns)
- jQuery
- Adding external libraries without justification

### Security
- Plaintext password storage
- Direct SQL string concatenation
- Unvalidated user input

Version Management

When changing the Constitution:

1. Increment version number
2. Record change history
3. Review compatibility with existing specs

## Change History

| Version | Date | Changes |
|---------|------|---------|
| 1.0.0 | 2025-12-24 | Initial version |
| 1.1.0 | 2025-12-25 | Added test coverage criteria |

Referencing in Specs

Include Constitution version in spec metadata:

---
id: user-auth
constitution_version: 1.0.0
---

Validation

sdd validate

• Warns on constitution_version mismatch
• Errors on forbidden practice violations