# Creating dependencies

A dependency allows you to specify JavaScript and CSS code that you want to be available to your interaction at runtime.

To add a dependency called my\_dependency, create the file extensions/dependencies/my\_dependency.html. Inside this file you can write lines of the form `<script src="my/file/path.js"></script>` specifying CSS or JS code. Alternatively you can use `<script>` tags to include JavaScript directly in this file.