Taming Claude: 13 Rules for AI-Generated Idiomatic Scala Code

Claude and similar AI models often generate syntactically correct but semantically unsafe Scala code, defaulting to null returns, mutable state, and Java-style patterns rather than functional idioms. A CLAUDE.md file with explicit rules channels AI toward type-safe, immutable code that aligns with Scala 3 and modern libraries like cats-effect. For teams scaling AI-assisted development, this becomes critical infrastructure to ensure generated code is both correct and maintainable.