<!--
Sync Impact Report:
- Version: 1.0.0 (Initial constitution)
- Created: 2025-10-08
- Type: Initial creation
- Modified Principles: N/A (new document)
- Added Sections: All sections (initial creation)
- Removed Sections: None
- Templates Status:
  ✅ plan-template.md - Constitution Check section aligns with principles
  ✅ spec-template.md - Requirements sections align with quality standards
  ✅ tasks-template.md - Task structure supports principle-driven development
- Follow-up TODOs: None
-->

# Claude Code Tools Constitution

## Core Principles

### I. Tool-First Architecture

Every feature MUST be designed as a standalone, reusable tool that enhances Claude Code's capabilities. Tools MUST be:
- Self-contained with clear, single responsibility
- Independently testable and documented
- Composable with other tools in the ecosystem
- Designed for both CLI and programmatic use

**Rationale**: Claude Code's power comes from its extensibility. Tools that follow this principle ensure maximum reusability and maintainability across the ecosystem.

### II. Developer Experience (DX) Priority

All tools, hooks, and agents MUST prioritize developer experience:
- Clear, intuitive APIs and interfaces
- Comprehensive documentation with examples
- Helpful error messages that guide users to solutions
- Progressive disclosure: simple by default, powerful when needed

**Rationale**: Claude Code users are developers. Poor DX creates friction and reduces adoption. Every interaction should feel effortless and empowering.

### III. Hook-Driven Extensibility

Extensibility MUST be achieved through well-defined hooks:
- Hooks MUST have clear lifecycle events and contracts
- Hook execution MUST be predictable and debuggable
- Hooks MUST support both sync and async operations where appropriate
- Hook failures MUST be graceful and informative

**Rationale**: Hooks are the foundation of Claude Code's extensibility. Well-designed hooks enable users to customize behavior without modifying core code.

### IV. Agent Specialization

AI agents MUST be purpose-built for specific domains:
- Each agent MUST have a clearly defined scope and responsibility
- Agents MUST be context-aware and use appropriate tools
- Agent prompts MUST be version-controlled and testable
- Agents MUST provide clear reasoning and actionable outputs

**Rationale**: General-purpose agents lead to unpredictable behavior. Specialized agents deliver consistent, high-quality results in their domain.

### V. Test-First Development (NON-NEGOTIABLE)

Testing MUST precede implementation:
- Write tests → Get user approval → Verify tests fail → Implement
- All tools MUST have unit tests for core functionality
- Integration tests MUST validate tool composition and hook interactions
- Agent behavior MUST be validated through prompt testing and output validation

**Rationale**: Claude Code tools are foundational infrastructure. Bugs cascade to all users. TDD ensures reliability and prevents regressions.

### VI. Observability & Debuggability

All components MUST be observable and debuggable:
- Tools MUST log operations at appropriate levels (debug, info, warn, error)
- Hooks MUST emit events for monitoring and debugging
- Agents MUST expose reasoning and decision-making processes
- Performance metrics MUST be measurable and trackable

**Rationale**: When tools fail in production, developers need visibility. Observability transforms frustrating debugging sessions into quick fixes.

### VII. Simplicity & YAGNI

Complexity MUST be justified:
- Start with the simplest solution that solves the problem
- Add complexity only when demonstrable need exists
- Prefer composition over inheritance
- Avoid premature optimization and feature bloat

**Rationale**: Claude Code's strength is its elegant simplicity. Every line of complexity is technical debt that slows development and confuses users.

## Development Workflow

### Specification-Driven Development

All features MUST follow the spec workflow:

1. **Specification Phase**: Create detailed spec using `/speckit.specify`
   - Define user scenarios and acceptance criteria
   - Identify functional requirements
   - Clarify ambiguities with `/speckit.clarify`

2. **Planning Phase**: Generate implementation plan using `/speckit.plan`
   - Research existing patterns and dependencies
   - Design data models and contracts
   - Validate against constitution principles

3. **Task Breakdown**: Generate actionable tasks using `/speckit.tasks`
   - Organize by user story for independent delivery
   - Mark parallel execution opportunities
   - Define clear dependencies

4. **Implementation**: Execute tasks using `/speckit.implement`
   - Write tests first (TDD)
   - Implement to pass tests
   - Document as you build

5. **Quality Assurance**: Validate using `/speckit.analyze`
   - Cross-artifact consistency checks
   - Constitution compliance verification
   - Integration testing validation

### Code Review Requirements

All pull requests MUST:
- Include tests that validate the feature
- Pass all existing tests without modification (unless explicitly refactoring)
- Update documentation for user-facing changes
- Include examples for new tools, hooks, or agents
- Demonstrate constitution compliance (especially Principles I-VII)

### Version Control & Breaking Changes

Version numbers MUST follow semantic versioning (MAJOR.MINOR.PATCH):
- **MAJOR**: Breaking changes to tool APIs, hook contracts, or agent interfaces
- **MINOR**: New tools, hooks, or agents; backward-compatible enhancements
- **PATCH**: Bug fixes, documentation updates, non-functional improvements

Breaking changes MUST:
- Be documented in CHANGELOG.md with migration guides
- Provide deprecation warnings for at least one MINOR version before removal
- Include automated migration scripts when feasible

## Quality Standards

### Documentation Requirements

All components MUST include:
- **README.md**: Overview, installation, quick start
- **API Documentation**: Function signatures, parameters, return values, examples
- **Usage Examples**: Real-world scenarios demonstrating common use cases
- **Troubleshooting Guide**: Common errors and solutions

### Performance Standards

Tools MUST meet these performance targets:
- CLI commands: <500ms startup time for simple operations
- Hook execution: <100ms overhead per hook invocation
- Agent responses: <10s for standard operations (excluding LLM latency)
- Memory footprint: <100MB for typical tool execution

### Security Requirements

All components MUST:
- Validate all user inputs to prevent injection attacks
- Never log or expose sensitive information (API keys, credentials, PII)
- Use secure defaults (e.g., restrictive file permissions)
- Document security considerations for user-configurable options

## Governance

### Constitutional Authority

This constitution supersedes all other project practices and guidelines. When conflicts arise between this constitution and other documentation, the constitution takes precedence.

### Amendment Process

Constitutional amendments MUST:
1. Be proposed via GitHub issue with clear rationale
2. Include impact analysis on existing tools, hooks, and agents
3. Receive approval from project maintainers
4. Include migration plan for affected components
5. Update dependent templates and documentation

### Compliance Review

All feature specifications MUST pass a Constitution Check (see plan-template.md) before implementation begins. The check validates:
- Alignment with Core Principles (I-VII)
- Adherence to Development Workflow
- Compliance with Quality Standards
- Security Requirements satisfaction

### Version Management & Documentation

Constitution changes MUST:
- Increment version number according to semantic versioning
- Update RATIFICATION_DATE only for initial adoption
- Update LAST_AMENDED_DATE for all subsequent changes
- Include Sync Impact Report (HTML comment at top of file) detailing all changes

**Version**: 1.0.0 | **Ratified**: 2025-10-08 | **Last Amended**: 2025-10-08
