TypeScript strict mode and Claude Code: better results with stricter config

Dev.to AI
Generative AI

Stricter TypeScript config produces better Claude Code output. Counterintuitive but consistent in my experience. Why strict mode helps When TypeScript strict mode is on, Claude's generated code has to satisfy the type checker. This forces Claude to handle null checks, correct return types, and proper type narrowing - things it sometimes skips without the constraint. With strict: false, Claude writes code that works but might be loose about types. With strict: true, the compiler forces correctness and Claude adapts. The CLAUDE.md rule Add: "This project uses TypeScript strict mode.