Modules (Runtime)
import { Module } from '@nuxt/types'
interface Options {
  a: boolean
  b: number
  c: string
}
const myModule: Module<Options> = function (moduleOptions) {
  // Use this, this.options, this.nuxt
  // Use moduleOptions
}
export default myModule
// REQUIRED if publishing the module as npm package
// export const meta = require('./package.json')
Read more about modules property, modules dir.