13 · Environments & Packaging
TypeScript
JavaScript with types
A language that builds on JavaScript by adding static types. Coding agents often edit `.ts` / `.tsx` files and lean on the type checker to catch mistakes before runtime.
Concrete example
“Convert this module to TypeScript” means add types and usually a `tsconfig`, not rewrite the product.
Why it matters
The default language of many modern web codebases agents touch.