app.config.globalProperties

An object that can be used to register global
properties that can be accessed on any component
instance inside the application.
For example, we may install this.$http for
data-fetching or this.$translate for
internationalization.

interface AppConfig {
  globalProperties: Record<string, any>
}

If a global property conflicts with a component’s
own property, the component’s own property will
have higher priority.

app.config.globalProperties.msg = 'hello'

This makes msg available inside any component
template in the application, and also on this of
any component instance:

export default {
  mounted() {
    console.log(this.msg) // 'hello'
  }
}