u

package.json

@@ -3,6 +3,7 @@
   "version": "1.0.0",
   "description": "",
   "main": "./bin/index.js",
+  "types": "./types/index.d.ts",
   "scripts": {
     "test": "echo \"Error: no test specified\" && exit 1"
   },

tsconfig.json

@@ -2,6 +2,8 @@
   "compilerOptions": {
     "outDir": "bin",
     "target": "es5", /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017','ES2018' or 'ESNEXT'. */
-    "module": "commonjs"
+    "module": "commonjs",
+    "declaration": true,
+    "declarationDir": "types"
   }
 }
\ No newline at end of file

types/Bar.d.ts

+import Foo from "./Foo";
+export default class Bar {
+    createFoo(): Foo;
+}

types/Foo.d.ts

+export default class Foo {
+    log(): void;
+}

types/index.d.ts

+import Bar from "./Bar";
+export { Bar };