Constitutional Engineering

The AI must operate under a constitution. Period.

The Principle

In traditional software development, we rely on conventions, style guides, and code reviews to maintain quality and consistency. But when AI enters the equation, these informal guardrails become dangerously inadequate. AI doesn't understand nuance—it needs explicit, enforceable rules.

Constitutional Engineering is the practice of defining an immutable set of rules that govern every AI interaction in your development environment. These aren't suggestions or guidelines—they're architectural constraints that cannot be violated.

How It Works

Every AI suggestion passes through multiple validation layers:

AI Suggestion → Constitutional Validation → Context Check → Action Verification → Human Review

If any layer fails, the suggestion is either modified to comply or rejected entirely.

Implementation in Hatcher

Playbooks: Your Project's Laws

Playbooks are executable specifications that define:

• Code patterns that must be followed
• Architectural decisions that cannot be violated
• Security boundaries that cannot be crossed
• Performance thresholds that must be maintained

# Example Playbook
name: API Security Constitution
rules:
  - no_public_endpoints_without_auth
  - all_inputs_must_be_validated
  - rate_limiting_required
  - audit_log_all_mutations

Think of it this way: Playbooks are the law, and Hatcher Actions are the police. Playbooks (.yaml) declare what the rules are in a human-readable way. Actions (.ts) provide the executable logic to enforce those rules in real-time.

Hatcher Actions: Enforcement in Real-Time

Actions are the enforcement mechanism—they intercept AI suggestions and validate them against your constitution before they ever reach your codebase.

// Example Action
export const validateAPIEndpoint: HatcherAction = {
  trigger: 'api.endpoint.created',
  validate: (code) => {
    // Check authentication
    if (!hasAuthDecorator(code)) {
      return reject('All endpoints must have authentication')
    }
    // Check input validation
    if (!hasInputValidation(code)) {
      return reject('All inputs must be validated')
    }
    return approve(code)
  },
}

The Power of Constitutional Engineering

1. Predictable AI Behavior

The AI becomes predictable because it's constrained by explicit rules. You know what it can and cannot do.

2. Team Alignment at Scale

Every developer, human or AI, follows the same constitution. No more "style wars" or inconsistent patterns.

3. Compliance by Design

Regulatory requirements become constitutional rules. GDPR, HIPAA, SOC2—encoded and enforced automatically.

4. Evolution Without Chaos

As your project evolves, you update the constitution. All future AI interactions immediately adapt to the new rules.

5. Unified Governance Across Paradigms

The constitution doesn't just apply to newly generated UI code. It governs how the entire system behaves, including how AI interacts with legacy business logic running in The Universal Fabricator. This provides a single, unified control plane over both the old and the new.

Real-World Example: The Security Constitution

Consider a fintech application where security is paramount:

constitution:
  data_handling:
    - encrypt_all_pii_at_rest
    - no_pii_in_logs
    - tokenize_payment_data

  authentication:
    - multi_factor_required
    - session_timeout_15_minutes
    - jwt_rotation_hourly

  api_design:
    - versioned_endpoints_only
    - deprecation_notice_90_days
    - backward_compatibility_required

With this constitution in place, the AI cannot:

• Generate code that logs sensitive data
• Create endpoints without proper authentication
• Suggest changes that break backward compatibility

Beyond Rules: Cultural Encoding

Constitutional Engineering isn't just about technical constraints—it's about encoding your engineering culture into the development process. Your values, priorities, and non-negotiables become part of the system itself.

This is how you scale culture. This is how you ensure that whether you have 10 developers or 1000, whether they're human or AI, everyone builds software the way you've decided it should be built.

Getting Started

1. Define Your Core Principles: What are your non-negotiables?
2. Create Your First Playbook: Start with one critical area (security, performance, etc.)
3. Write Enforcement Actions: Turn rules into code
4. Iterate and Expand: Grow your constitution as you learn

The constitution isn't set in stone—it evolves with your understanding. But at any given moment, it's the law, and nothing gets past it without your explicit approval.

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Constitutional Engineering transforms AI from an unpredictable oracle into a disciplined team member that respects your rules, follows your patterns, and upholds your standards. Every time.

Define Your Development Constitution

Create unbreakable rules that every AI and developer must follow

Build Your Playbooks→

Your standards. Your rules. Enforced automatically.