1. What is a Volto add-on#
There are several advanced scenarios where we might want to have more control and flexibility beyond using the plain Volto project to build a site.
The addon can be published to an NPM registry or directly installed from github by Yarn. By using mrs-develop, it's possible to have a workflow similar to zc.buildout's mr.developer, where you can "checkout" an addon for development.
An addon can be almost anything that a Volto project can be. They can:
provide additional views and blocks
override or extend Volto's builtin views, blocks, settings
shadow (customize) Volto's (or another addon's) modules
register custom routes
provide custom Redux actions and reducers
register custom Express middleware for Volto's server process
tweak Volto's Webpack configuration, load custom Razzle and Webpack plugins
even provide a custom theme, just like a regular Volto project does.