Consumption

Downloading

Getting type declarations requires no tools apart from npm.

As an example, getting the declarations for a library like lodash takes nothing more than the following command

npm install --save-dev @types/lodash

It is worth noting that if the npm package already includes its declaration file as described in Publishing, downloading the corresponding @types package is not needed.

Consuming

From there you’ll be able to use lodash in your TypeScript code with no fuss. This works for both modules and global code.

For example, once you’ve npm install-ed your type declarations, you can use imports and write

import * as _ from "lodash";
_.padStart("Hello TypeScript!", 20, " ");

or if you’re not using modules, you can just use the global variable _.

_.padStart("Hello TypeScript!", 20, " ");

Searching

For the most part, type declaration packages should always have the same name as the package name on npm, but prefixed with @types/, but if you need, you can check out this Type Search to find the package for your favorite library.

Note: if the declaration file you are searching for is not present, you can always contribute one back and help out the next developer looking for it. Please see the DefinitelyTyped contribution guidelines page for details.

© 2012-2021 Microsoft
Licensed under the Apache License, Version 2.0.
https://www.typescriptlang.org/docs/handbook/declaration-files/consumption.html