To let other TypeScript libraries use your library, you need to create a .d.ts file to declare all your public APIs of your library with the typing information. The enforce to clearly list all your public APIs for each libraries you are developing. We found it serves as a quick and accurate reference for all your APIs.
Refer to https://github.com/borisyankov/DefinitelyTyped for TypeScript definition files created for large amounts of JavaScript libraries.