You can extend these properties of Hygen, using a special .hygen.js file:

  • Helper functions in templates.
  • Customizing logger, template location and shell executor.
  • (WIP) Custom generator operations in addition to the built-in add, inject, shell


Hygen supports a bubbling-up mechanism for searching a .hygen.js file and loading it. Where ever you run hygen from, it will start searching for this file upwards, and stop at the first one it finds.

This means:

  • You can set up a single file per project.
  • For some special sub-projects, set a different file for a different behavior.
  • You can also set up one global file to use if you drop it in your user folder.

Note: The current strategy when there are two or more .hygen.js files in the path upwards is to take the first one and ignore the rest.


Here's a template that uses a function that doesn't exist in the helper accessor h. This function is plainly called extended, for lack of a better name.

to: given/hygen-js/new.md
this demonstrates hygen loaded up .hygen.js and extended helpers.
<%= h.extended('hello') %>

In order to add the function extended to the standard hygen helpers collection, we'll create a .hygen.js file at the root of our project:


This .hygen.js file will be the home of all of our extension points. For this example, we'll use the following content:

module.exports = {
    helpers: {
        extended: s => s.toUpperCase()

Note that beyond inlining a utility function like in this example, you can require and use any piece of code in your project here and export it for Hygen to use.