Reflect.ts specifies a reflection API for JavaScript, capable of running from any host. What this means is that, although the API allows reflection operations on live JS objects, the API need not be used from within JavaScript—reflect.ts is just as suitable for use from e.g., C#, Java, etc.

The API was forked from Allen Wirfs-Brock's original spec for jsmirrors <https://github.com/allenwb/jsmirrors/>, and the specification was rewritten in a dialect of TypeScript. (The reflect.ts reference implementation remains based on the original jsmirrors prototype; despite the name, there are no plans to rewrite the implementation in TypeScript.)