Publishing Type Definitions It can be useful to be able to publish these types in custom NPM repos e.g. Gitlab Configuring package.json File Including src and dist folders use files key in package.json to indicate which directories should be published ( https://stackoverflow.com/questions/67523877/index-d-ts-file-not-published-to-npm ). By default you likely want to publish both the source code in src and the compiled/transpiled typescript->js files in dist e.g. { "files": [ "dist", "src" ], } Including types and main You also need to include a types property which tells npm where your defined types ( index.d.ts ) sits - this is likely to be in dist/index.d.ts if you follow the conventions in this document. Main module In a node module you'd probably use src/index.js but we want to use dist/index.js - this will be the compiled version of our typescript module. Configuring tsconfig.json You probably want something like this: { "compilerOptions": { "sourceMap": true, "outDir": "dist", "strict": true, "lib": [ "esnext" ], "allowJs": true, "declaration": true, "esModuleInterop": true }, "include": ["src/**/*"], } Use dist for our outdir so that the output from transpilation goes to the right place. Use declaration: true to have tsc produce an index.d.ts declaration file and plonk it into the dist folder so that it is picked up by the package.json we configured above.