# Using Vue in Markdown

# Browser API Access Restrictions

Because VuePress applications are server-rendered in Node.js when generating static builds, any Vue usage must conform to the universal code requirements (opens new window). In short, make sure to only access Browser / DOM APIs in beforeMount or mounted hooks.

If you are using or demoing components that are not SSR friendly (for example containing custom directives), you can wrap them inside the built-in <ClientOnly> component: