Type Hints Best Practices with mypy Strict Mode

Core Principles

All Python code in Vibekit MUST pass mypy in strict mode with zero errors. Type hints are not optional - they are a fundamental requirement for code quality and maintainability.

Explicit Return Type Annotations

Every exported function must declare its return type:

# ✅ REQUIRED: Explicit return types for all exported functions
def calculate_total(items: list[float]) -> float:
    """Calculate sum of items."""
    return sum(items)