TypeScript

Strict, type-safe TypeScript for any codebase — frontend, backend, libraries, CLIs.

When to activate

• Writing or modifying .ts or .tsx files
• Reviewing TypeScript code for quality
• Refactoring JavaScript to TypeScript
• Debugging type errors or inference failures
• Setting up or auditing tsconfig.json

Core rules

NEVER

• Use any — use unknown and narrow with type guards
• Use as type assertions without runtime validation
• Use @ts-ignore — use @ts-expect-error with a reason comment