diff --git a/.eslintrc b/.eslintrc
index 2c23dddc42..442bafddf4 100644
--- a/.eslintrc
+++ b/.eslintrc
@@ -2,11 +2,25 @@
   "globals": {
     "NodeJS": true
   },
+  "plugins": ["jsdoc"],
   "extends": [
+    "plugin:jsdoc/recommended",
     "@nuxtjs/eslint-config-typescript"
   ],
   "rules": {
     "no-console": "off",
-    "vue/one-component-per-file": "off"
+    "vue/one-component-per-file": "off",
+    "jsdoc/require-jsdoc": "off",
+    "jsdoc/require-param": "off",
+    "jsdoc/require-returns": "off",
+    "jsdoc/require-param-type": "off"
+  },
+  "settings": {
+    "jsdoc": {
+      "tagNamePreference": {
+        "warning": "warning",
+        "note": "note"
+      }
+    }
   }
 }
diff --git a/package.json b/package.json
index 51c356c6d8..d3dfef767a 100644
--- a/package.json
+++ b/package.json
@@ -23,6 +23,7 @@
     "@types/jest": "^26.0.22",
     "@types/node": "^14.14.37",
     "eslint": "^7.24.0",
+    "eslint-plugin-jsdoc": "^32.3.0",
     "jest": "^26.6.3",
     "jiti": "^1.9.1",
     "lerna": "^4.0.0",
diff --git a/packages/app/src/composables/data.ts b/packages/app/src/composables/data.ts
index 0aee2c87f7..1dd6df9181 100644
--- a/packages/app/src/composables/data.ts
+++ b/packages/app/src/composables/data.ts
@@ -13,6 +13,7 @@ export function ensureReactive<
 
 /**
  * Returns a unique string suitable for syncing data between server and client.
+ *
  * @param nuxt (optional) A Nuxt instance
  * @param vm (optional) A Vue component - by default it will use the current instance
  */
@@ -37,6 +38,7 @@ export function useSSRRef (nuxt = useNuxt(), vm = getCurrentInstance()): string
 
 /**
  * Allows accessing reactive data that can be synced between server and client.
+ *
  * @param nuxt (optional) A Nuxt instance
  * @param vm (optional) A Vue component - by default it will use the current instance
  */
@@ -53,6 +55,7 @@ export function useData<T = Record<string, any>> (
 
 /**
  * Allows accessing reactive global data that can be synced between server and client.
+ *
  * @param nuxt - (optional) A Nuxt instance
  */
 export function useGlobalData (nuxt = useNuxt()): Record<string, any> {
diff --git a/packages/app/src/composables/hydrate.ts b/packages/app/src/composables/hydrate.ts
index cd05de4639..74b464f4b7 100644
--- a/packages/app/src/composables/hydrate.ts
+++ b/packages/app/src/composables/hydrate.ts
@@ -2,6 +2,7 @@ import { useNuxt } from '@nuxt/app'
 
 /**
  * Allows full control of the hydration cycle to set and receive data from the server.
+ *
  * @param key a unique key to identify the data in the Nuxt payload
  * @param get a function that returns the value to set the initial data
  * @param set a function that will receive the data on the client-side
diff --git a/packages/app/src/nuxt.ts b/packages/app/src/nuxt.ts
index 89cf5298a2..b71ff09a56 100644
--- a/packages/app/src/nuxt.ts
+++ b/packages/app/src/nuxt.ts
@@ -101,6 +101,7 @@ export const setNuxtInstance = (nuxt: Nuxt | null) => {
 
 /**
  * Ensures that the setup function passed in has access to the Nuxt instance via `useNuxt`.
+ *
  * @param nuxt A Nuxt instance
  * @param setup The function to call
  */
diff --git a/packages/kit/src/config/env.ts b/packages/kit/src/config/env.ts
index 5d278a1c90..155bee926e 100644
--- a/packages/kit/src/config/env.ts
+++ b/packages/kit/src/config/env.ts
@@ -3,15 +3,37 @@ import { existsSync, promises as fsp } from 'fs'
 import dotenv from 'dotenv'
 
 export interface LoadDotEnvOptions {
+  /** The project root directory (either absolute or relative to the current working directory). */
   rootDir: string
+  /**
+   * What file to look in for environment variables (either absolute or relative
+   * to the current working directory). For example, `.env`.
+   */
   dotenvFile: string
+  /**
+   * Whether to interpolate variables within .env.
+   *
+   * @example
+   * ```env
+   * BASE_DIR="/test"
+   * # resolves to "/test/further"
+   * ANOTHER_DIR="${BASE_DIR}/further"
+   * ```
+   */
   expand: boolean
-  env: typeof process.env
+  /** An object describing environment variables (key, value pairs). */
+  env: NodeJS.ProcessEnv
 }
 
-export async function loadEnv (rootDir) {
+/**
+ * Load and interpolate environment variables into `process.env`.
+ * If you need more control (or access to the values), consider using `loadDotenv` instead
+ *
+ * @param rootDir - The project root directory (either absolute or relative to the current working directory).
+ */
+export async function loadEnv (rootDir: string) {
   // Load env
-  const env = await loalDotenv({
+  const env = await loadDotenv({
     rootDir,
     dotenvFile: '.env',
     env: process.env,
@@ -26,12 +48,13 @@ export async function loadEnv (rootDir) {
   }
 }
 
-export async function loalDotenv (opts: LoadDotEnvOptions) {
+/** Load environment variables into an object. */
+export async function loadDotenv (opts: LoadDotEnvOptions) {
   const env = Object.create(null)
 
   const dotenvFile = resolve(opts.rootDir, opts.dotenvFile)
 
-  if (await existsSync(dotenvFile)) {
+  if (existsSync(dotenvFile)) {
     const parsed = dotenv.parse(await fsp.readFile(dotenvFile, 'utf-8'))
     Object.assign(env, parsed)
   }
@@ -51,13 +74,13 @@ export async function loalDotenv (opts: LoadDotEnvOptions) {
 }
 
 // Based on https://github.com/motdotla/dotenv-expand
-function expand (target, source = {}, parse = v => v) {
-  function getValue (key) {
+function expand (target: Record<string, any>, source: Record<string, any> = {}, parse = (v: any) => v) {
+  function getValue (key: string) {
     // Source value 'wins' over target value
     return source[key] !== undefined ? source[key] : target[key]
   }
 
-  function interpolate (value, parents = []) {
+  function interpolate (value: unknown, parents: string[] = []) {
     if (typeof value !== 'string') {
       return value
     }
@@ -66,7 +89,7 @@ function expand (target, source = {}, parse = v => v) {
       const parts = /(.?)\${?([a-zA-Z0-9_:]+)?}?/g.exec(match)
       const prefix = parts[1]
 
-      let value, replacePart
+      let value, replacePart: string
 
       if (prefix === '\\') {
         replacePart = parts[0]
diff --git a/packages/kit/src/config/load.ts b/packages/kit/src/config/load.ts
index 3aec30d2a4..22ba9cdd48 100644
--- a/packages/kit/src/config/load.ts
+++ b/packages/kit/src/config/load.ts
@@ -7,9 +7,12 @@ import { NuxtOptions } from '../types/config'
 import nuxtConfigSchema from './schema'
 
 export interface LoadNuxtConfigOptions {
+  /** Your project root directory (either absolute or relative to the current working directory). */
   rootDir?: string
+  /** The path to your `nuxt.config` file (either absolute or relative to your project `rootDir`). */
   configFile?: string
-  config?: any
+  /** Any overrides to your Nuxt configuration. */
+  config?: Record<string, any>
 }
 
 export function loadNuxtConfig (opts: LoadNuxtConfigOptions): NuxtOptions {
diff --git a/packages/kit/src/config/schema/_app.ts b/packages/kit/src/config/schema/_app.ts
index 3a2394302b..cfaec62297 100644
--- a/packages/kit/src/config/schema/_app.ts
+++ b/packages/kit/src/config/schema/_app.ts
@@ -4,16 +4,23 @@ import defu from 'defu'
 import { isRelative, joinURL, hasProtocol } from 'ufo'
 
 export default {
-  /**
-   * Vue.js configuration
-   */
+  /** Vue.js config */
   vue: {
+    /**
+     * Properties that will be set directly on `Vue.config` for vue@2 and `app.config` for vue@3.
+     *
+     * @see [vue@2 Documentation](https://vuejs.org/v2/api/#Global-Config)
+     * @see [vue@3 Documentation](https://v3.vuejs.org/api/application-config.html)
+     */
     config: {
       silent: { $resolve: (val, get) => val ?? get('dev') },
       performance: { $resolve: (val, get) => val ?? get('dev') }
     }
   },
 
+  /**
+   * Nuxt App configuration.
+   */
   app: {
     $resolve: (val, get) => {
       const useCDN = hasProtocol(get('build.publicPath'), true) && !get('dev')
@@ -27,7 +34,21 @@ export default {
   },
 
   /**
-   * Uses {srcDir}/app.html if exists by default otherwise nuxt default
+   * The path to a templated HTML file for rendering Nuxt responses.
+   * Uses `<srcDir>/app.html` if it exists or the Nuxt default template if not.
+   *
+   * @example
+   * ```html
+   * <!DOCTYPE html>
+   * <html {{ HTML_ATTRS }}>
+   *   <head {{ HEAD_ATTRS }}>
+   *     {{ HEAD }}
+   *   </head>
+   *   <body {{ BODY_ATTRS }}>
+   *     {{ APP }}
+   *   </body>
+   * </html>
+   * ```
    */
   appTemplatePath: {
     $resolve: (val, get) => {
@@ -41,6 +62,10 @@ export default {
     }
   },
 
+  /**
+   * Enable or disable vuex store.
+   * By default is enbled if there is store / directory
+   */
   store: {
     $resolve: (val, get) => val !== false &&
       existsSync(join(get('srcDir'), get('dir.store'))) &&
@@ -49,47 +74,145 @@ export default {
   },
 
   /**
-   * debug errorss
+   * Options to pass directly to `vue-meta`.
+   *
+   * @see [documentation](https://vue-meta.nuxtjs.org/api/#plugin-options).
    */
-  debug: {
-    $resolve: (val, get) => val ?? get('dev')
-  },
-
   vueMeta: null,
 
+  /**
+   * Set default configuration for `<head>` on every page.
+   *
+   * @see [documentation](https://vue-meta.nuxtjs.org/api/#metainfo-properties) for specifics.
+   */
   head: {
+    /** Each item in the array maps to a newly-created <meta> element, where object properties map to attributes. */
     meta: [],
+    /** Each item in the array maps to a newly-created <link> element, where object properties map to attributes. */
     link: [],
+    /** Each item in the array maps to a newly-created <style> element, where object properties map to attributes. */
     style: [],
+    /** Each item in the array maps to a newly-created <script> element, where object properties map to attributes. */
     script: []
   },
 
+  /**
+   * Configuration for the Nuxt `fetch()` hook.
+   */
   fetch: {
+    /** Whether to enable `fetch()` on the server. */
     server: true,
+    /** Whether to enable `fetch()` on the client. */
     client: true
   },
 
+  /**
+   * An array of nuxt app plugins.
+   *
+   * Each plugin can be a string (which can be an absolute or relative path to a file).
+   * If it ends with `.client` or `.server` then it will be automatically loaded only
+   * in the appropriate context.
+   *
+   * It can also be an object with `src` and `mode` keys.
+   *
+   * @example
+   * ```js
+   * plugins: [
+   *   '~/plugins/foo.client.js', // only in client side
+   *   '~/plugins/bar.server.js', // only in server side
+   *   '~/plugins/baz.js', // both client & server
+   *   { src: '~/plugins/both-sides.js' },
+   *   { src: '~/plugins/client-only.js', mode: 'client' }, // only on client side
+   *   { src: '~/plugins/server-only.js', mode: 'server' } // only on server side
+   * ]
+   * ```
+   */
   plugins: [],
 
+  /**
+   * You may want to extend plugins or change their order. For this, you can pass
+   * a function using `extendPlugins`. It accepts an array of plugin objects and
+   * should return an array of plugin objects.
+   */
   extendPlugins: null,
 
+  /**
+   * You can define the CSS files/modules/libraries you want to set globally
+   * (included in every page).
+   *
+   * Nuxt will automatically guess the file type by its extension and use the
+   * appropriate pre-processor. You will still need to install the required
+   * loader if you need to use them.
+   *
+   * @example
+   * ```js
+   * css: [
+   *   // Load a Node.js module directly (here it's a Sass file)
+   *   'bulma',
+   *   // CSS file in the project
+   *   '@/assets/css/main.css',
+   *   // SCSS file in the project
+   *   '@/assets/css/main.scss'
+   * ]
+   * ```
+   */
   css: [],
 
+  /**
+   * An object where each key name maps to a path to a layout .vue file.
+   *
+   * Normally there is no need to configure this directly.
+   */
   layouts: {},
 
+  /**
+   * Set a custom error page layout.
+   *
+   * Normally there is no need to configure this directly.
+   */
   ErrorPage: null,
 
+  /**
+   * Configure the Nuxt loading progress bar component that's shown between
+   * routes. Set to `false` to disable. You can also customize it or create
+   * your own component.
+   */
   loading: {
+    /** CSS color of the progress bar */
     color: 'black',
+    /**
+     * CSS color of the progress bar when an error appended while rendering
+     * the route (if data or fetch sent back an error for example).
+     */
     failedColor: 'red',
+    /** Height of the progress bar (used in the style property of the progress bar). */
     height: '2px',
+    /**
+     * In ms, wait for the specified time before displaying the progress bar.
+     * Useful for preventing the bar from flashing.
+     */
     throttle: 200,
+    /**
+     * In ms, the maximum duration of the progress bar, Nuxt assumes that the
+     * route will be rendered before 5 seconds.
+     */
     duration: 5000,
+    /** Keep animating progress bar when loading takes longer than duration. */
     continuous: false,
+    /** Set the direction of the progress bar from right to left. */
     rtl: false,
+    /** Set to false to remove default progress bar styles (and add your own). */
     css: true
   },
 
+  /**
+   * Show a loading spinner while the page is loading (only when `ssr: false`).
+   *
+   * Set to `false` to disable. Alternatively, you can pass a string name or an object for more
+   * configuration. The name can refer to an indicator from [SpinKit](https://tobiasahlin.com/spinkit/)
+   * or a path to an HTML template of the indicator source code (in this case, all the
+   * other options will be passed to the template.)
+   */
   loadingIndicator: {
     $resolve: (val, get) => {
       if (typeof val === 'string') {
@@ -107,6 +230,15 @@ export default {
     }
   },
 
+  /**
+   * Used to set the default properties of the page transitions.
+   *
+   * You can either pass a string (the transition name) or an object with properties to bind
+   * to the `<Transition>` component that will wrap your pages.
+   *
+   * @see [vue@2 documentation](https://vuejs.org/v2/guide/transitions.html)
+   * @see [vue@3 documentation](https://v3.vuejs.org/guide/transitions-enterleave.html)
+   */
   pageTransition: {
     $resolve: val => typeof val === 'string' ? { name: val } : val,
     name: 'page',
@@ -117,25 +249,50 @@ export default {
     appearToClass: 'appear-to'
   },
 
+  /**
+   * Used to set the default properties of the layout transitions.
+   *
+   * You can either pass a string (the transition name) or an object with properties to bind
+   * to the `<Transition>` component that will wrap your layouts.
+   *
+   * @see [vue@2 documentation](https://vuejs.org/v2/guide/transitions.html)
+   * @see [vue@3 documentation](https://v3.vuejs.org/guide/transitions-enterleave.html)
+   */
   layoutTransition: {
     $resolve: val => typeof val === 'string' ? { name: val } : val,
     name: 'layout',
     mode: 'out-in'
   },
 
+  /**
+   * You can disable specific Nuxt features that you do not want.
+   */
   features: {
+    /** Set to false to disable Nuxt vuex integration */
     store: true,
+    /** Set to false to disable layouts */
     layouts: true,
+    /** Set to false to disable Nuxt integration with `vue-meta` and the `head` property */
     meta: true,
+    /** Set to false to disable middleware */
     middleware: true,
+    /** Set to false to disable transitions */
     transitions: true,
+    /** Set to false to disable support for deprecated features and aliases */
     deprecations: true,
+    /** Set to false to disable the Nuxt `validate()` hook */
     validate: true,
+    /** Set to false to disable the Nuxt `asyncData()` hook */
     asyncData: true,
+    /** Set to false to disable the Nuxt `fetch()` hook */
     fetch: true,
+    /** Set to false to disable `$nuxt.isOnline` */
     clientOnline: true,
+    /** Set to false to disable prefetching behavior in `<NuxtLink>` */
     clientPrefetch: true,
+    /** Set to false to disable extra component aliases like `<NLink>` and `<NChild>` */
     componentAliases: true,
+    /** Set to false to disable the `<ClientOnly>` component (see [docs](https://github.com/egoist/vue-client-only)) */
     componentClientOnly: true
   }
 }
diff --git a/packages/kit/src/config/schema/_common.ts b/packages/kit/src/config/schema/_common.ts
index d31bd26bdc..2af687aa0d 100644
--- a/packages/kit/src/config/schema/_common.ts
+++ b/packages/kit/src/config/schema/_common.ts
@@ -5,21 +5,101 @@ import { pascalCase } from 'scule'
 import jiti from 'jiti'
 
 export default {
+  /**
+   * Define the workspace directory of your application.
+   *
+   * This property can be overwritten (for example, running `nuxt ./my-app/`
+   * will set the `rootDir` to the absolute path of `./my-app/` from the
+   * current/working directory.
+   *
+   * It is normally not needed to configure this option.
+   */
   rootDir: {
     $resolve: val => typeof val === 'string' ? resolve(val) : process.cwd()
   },
 
+  /**
+   * Define the source directory of your Nuxt application.
+   *
+   * If a relative path is specified it will be relative to the `rootDir`.
+   *
+   * @example
+   * ```js
+   * export default {
+   *   srcDir: 'client/'
+   * }
+   * ```
+   * This would work with the following folder structure:
+   * ```bash
+   * -| app/
+   * ---| node_modules/
+   * ---| nuxt.config.js
+   * ---| package.json
+   * ---| client/
+   * ------| assets/
+   * ------| components/
+   * ------| layouts/
+   * ------| middleware/
+   * ------| pages/
+   * ------| plugins/
+   * ------| static/
+   * ------| store/
+   * ```
+   */
   srcDir: {
     $resolve: (val, get) => resolve(get('rootDir'), val || '.')
   },
 
+  /**
+   * Define the directory where your built Nuxt files will be placed.
+   *
+   * Many tools assume that `.nuxt` is a hidden directory (because it starts
+   * with a `.`). If that is a problem, you can use this option to prevent that.
+   *
+   * @example
+   * ```js
+   * export default {
+   *   buildDir: 'nuxt-build'
+   * }
+   * ```
+   */
   buildDir: {
     $resolve: (val, get) => resolve(get('rootDir'), val || '.nuxt')
   },
 
+  /**
+   * Whether Nuxt is running in development mode.
+   *
+   * Normally you should not need to set this.
+   */
   dev: Boolean(env.dev),
+
+  /**
+   * Whether your app is being unit tested
+   */
   test: Boolean(env.test),
-  debug: undefined,
+
+  /**
+   * Set to true to enable debug mode.
+   * By default it's only enabled in development mode.
+   */
+  debug: {
+    $resolve: (val, get) => val ?? get('dev')
+  },
+
+  /**
+   * The env property defines environment variables that should be available
+   * throughout your app (server- and client-side). They can be assigned using
+   * server side environment variables.
+   *
+   * **Note**: Nuxt uses webpack's `definePlugin` to define these environment variables.
+   * This means that the actual `process` or `process.env` from Node.js is neither
+   * available nor defined. Each of the `env` properties defined here is individually
+   * mapped to `process.env.xxxx` and converted during compilation.
+   *
+   * **Note**: Environment variables starting with `NUXT_ENV_` are automatically injected
+   * into the process environment.
+   */
   env: {
     $resolve: (val) => {
       val = { ...val }
@@ -32,6 +112,12 @@ export default {
     }
   },
 
+  /**
+   * Set the method Nuxt uses to require modules, such as loading `nuxt.config`, server
+   * middleware, and so on - defaulting to `jiti` (which has support for TypeScript and ESM syntax).
+   *
+   * @see [jiti](https://github.com/unjs/jiti)
+   */
   createRequire: {
     $resolve: (val: any) => {
       val = process.env.NUXT_CREATE_REQUIRE || val ||
@@ -46,27 +132,130 @@ export default {
     }
   },
 
+  /**
+   * Whether your Nuxt app should be built to be served by the Nuxt server (`server`)
+   * or as static HTML files suitable for a CDN or other static file server (`static`).
+   *
+   * This is unrelated to `ssr`.
+   */
   target: {
     $resolve: val => ['server', 'static'].includes(val) ? val : 'server'
   },
 
+  /**
+   * Whether to enable rendering of HTML - either dynamically (in server mode) or at generate time.
+   * If set to `false` and combined with `static` target, generated pages will simply display
+   * a loading screen with no content.
+   */
   ssr: true,
 
+  /**
+   * @deprecated use ssr option
+   */
   mode: {
     $resolve: (val, get) => val || (get('ssr') ? 'spa' : 'universal'),
     $schema: { deprecated: '`mode` option is deprecated' }
   },
 
+  /**
+   * Whether to produce a separate modern build targeting browsers that support ES modules.
+   *
+   * Set to `'server'` to enable server mode, where the Nuxt server checks
+   * browser version based on the user agent and serves the correct bundle.
+   *
+   * Set to `'client'` to serve both the modern bundle with `<script type="module">`
+   * and the legacy bundle with `<script nomodule>`. It will also provide a
+   * `<link rel="modulepreload">` for the modern bundle. Every browser that understands
+   * the module type will load the modern bundle while older browsers fall back to the
+   * legacy (transpiled) bundle.
+   *
+   * If you have set `modern: true` and are generating your app or have `ssr: false`,
+   * modern will be set to `'client'`.
+   *
+   * If you have set `modern: true` and are serving your app, modern will be set to `'server'`.
+   *
+   * @see [concept of modern mode](https://philipwalton.com/articles/deploying-es2015-code-in-production-today/)
+   */
   modern: undefined,
 
+  /**
+   * Modules are Nuxt extensions which can extend its core functionality and add endless integrations
+   *
+   * Each module is either a string (which can refer to a package, or be a path to a file), a
+   * tuple with the module as first string and the options as a second object, or an inline module function.
+   *
+   * Nuxt tries to resolve each item in the modules array using node require path
+   * (in `node_modules`) and then will be resolved from project `srcDir` if `~` alias is used.
+   *
+   * **Note**: Modules are executed sequentially so the order is important.
+   *
+   * @example
+   * ```js
+   * modules: [
+   *   // Using package name
+   *   '@nuxtjs/axios',
+   *   // Relative to your project srcDir
+   *   '~/modules/awesome.js',
+   *   // Providing options
+   *   ['@nuxtjs/google-analytics', { ua: 'X1234567' }],
+   *   // Inline definition
+   *   function () {}
+   * ]
+   * ```
+   */
   modules: [],
+
+  /**
+   * Modules that are only required during development and build time.
+   *
+   * Modules are Nuxt extensions which can extend its core functionality and add endless integrations
+   *
+   * Each module is either a string (which can refer to a package, or be a path to a file), a
+   * tuple with the module as first string and the options as a second object, or an inline module function.
+   *
+   * Nuxt tries to resolve each item in the modules array using node require path
+   * (in `node_modules`) and then will be resolved from project `srcDir` if `~` alias is used.
+   *
+   * **Note**: Modules are executed sequentially so the order is important.
+   *
+   * @example
+   * ```js
+   * modules: [
+   *   // Using package name
+   *   '@nuxtjs/axios',
+   *   // Relative to your project srcDir
+   *   '~/modules/awesome.js',
+   *   // Providing options
+   *   ['@nuxtjs/google-analytics', { ua: 'X1234567' }],
+   *   // Inline definition
+   *   function () {}
+   * ]
+   * ```
+   *
+   * **Note**: Using `buildModules` helps to make production startup faster and also significantly
+   * decreases the size of `node_modules` in production deployments. Please refer to each
+   * module's documentation to see if it is recommended to use `modules` or `buildModules`.
+   */
   buildModules: [],
+
+  /**
+   * Built-in ah-hoc modules
+   *
+   *  @private
+   */
   _modules: [],
 
+  /**
+   * Allows customizing the global ID used in the main HTML template as well as the main
+   * Vue instance name and other options.
+   */
   globalName: {
     $resolve: val => (typeof val === 'string' && /^[a-zA-Z]+$/.test(val)) ? val.toLocaleLowerCase() : 'nuxt'
   },
 
+  /**
+   * Customizes specific global names (they are based on `globalName` by default).
+   */
   globals: {
     id: globalName => `__${globalName}`,
     nuxt: globalName => `$${globalName}`,
@@ -76,6 +265,70 @@ export default {
     loadedCallback: globalName => `_on${pascalCase(globalName)}Loaded`
   },
 
+  /**
+   * Server middleware are connect/express/h3-shaped functions that handle server-side requests. They
+   * run on the server and before the Vue renderer.
+   *
+   * By adding entries to `serverMiddleware` you can register additional routes or modify `req`/`res`
+   * objects without the need for an external server.
+   *
+   * You can pass a string, which can be the name of a node dependency or a path to a file. You
+   * can also pass an object with `path` and `handler` keys. (`handler` can be a path or a
+   * function.)
+   *
+   * @example
+   * ```js
+   * serverMiddleware: [
+   *   // Will register redirect-ssl npm package
+   *   'redirect-ssl',
+   *   // Will register file from project server-middleware directory to handle /server-middleware/* requires
+   *   { path: '/server-middleware', handler: '~/server-middleware/index.js' },
+   *   // We can create custom instances too
+   *   { path: '/static2', handler: serveStatic(__dirname + '/static2') }
+   * ]
+   * ```
+   *
+   * **Note**: If you don't want middleware to run on all routes you should use the object
+   * form with a specific path.
+   *
+   * If you pass a string handler, Nuxt will expect that file to export a default function
+   * that handles `(req, res, next) => void`.
+   *
+   * @example
+   * ```js
+   * export default function (req, res, next) {
+   *   // req is the Node.js http request object
+   *   console.log(req.url)
+   *   // res is the Node.js http response object
+   *   // next is a function to call to invoke the next middleware
+   *   // Don't forget to call next at the end if your middleware is not an endpoint!
+   *   next()
+   * }
+   * ```
+   *
+   * Alternatively, it can export a connect/express/h3-type app instance.
+   * @example
+   * ```js
+   * const bodyParser = require('body-parser')
+   * const app = require('express')()
+   * app.use(bodyParser.json())
+   * app.all('/getJSON', (req, res) => {
+   *   res.json({ data: 'data' })
+   * })
+   * module.exports = app
+   * ```
+   *
+   * Alternatively, instead of passing an array of `serverMiddleware`, you can pass an object
+   * whose keys are the paths and whose values are the handlers (string or function).
+   * @example
+   * ```js
+   * serverMiddleware: {
+   *   '/a': '~/server-middleware/a.js',
+   *   '/b': '~/server-middleware/b.js',
+   *   '/c': '~/server-middleware/c.js'
+   * }
+   * ```
+   */
   serverMiddleware: {
     $resolve: (val: any) => {
       if (!val) {
@@ -88,6 +341,21 @@ export default {
     }
   },
 
+  /**
+   * Used to set the modules directories for path resolving (for example, webpack's
+   * `resolveLoading`, `nodeExternals` and `postcss`).
+   *
+   * The configuration path is relative to `options.rootDir` (default is current working directory).
+   *
+   * Setting this field may be necessary if your project is organized as a yarn workspace-styled mono-repository.
+   *
+   * @example
+   * ```js
+   * export default {
+   *   modulesDir: ['../../node_modules']
+   * }
+   * ```
+   */
   modulesDir: {
     $default: ['node_modules'],
     $resolve: (val, get) => [].concat(
@@ -96,22 +364,84 @@ export default {
     )
   },
 
+  /**
+   * Customize default directory structure used by nuxt.
+   * It is better to stick with defaults unless needed.
+   */
   dir: {
+    /** The assets directory (aliased as `~assets` in your build) */
     assets: 'assets',
+    /** The directory containing app template files like `app.html` and `router.scrollBehavior.js` */
     app: 'app',
+    /** The layouts directory, each file of which will be auto-registered as a Nuxt layout. */
     layouts: 'layouts',
+    /** The middleware directory, each file of which will be auto-registered as a Nuxt middleware. */
     middleware: 'middleware',
+    /** The directory which will be processed to auto-generate your application page routes. */
     pages: 'pages',
+    /**
+     * Your static directory, which will be directly accessible via the Nuxt server and copied
+     * across into your `dist` folder when your app is generated.
+     */
     static: 'static',
+    /** The folder which will be used to auto-generate your Vuex store structure. */
     store: 'store'
   },
 
+  /**
+   * The extensions that should be resolved by the Nuxt resolver.
+   */
   extensions: {
     $resolve: val => ['.js', '.mjs', '.ts', '.tsx', '.vue'].concat(val).filter(Boolean)
   },
 
+  /**
+   * The style extensions that should be resolved by the Nuxt resolver (for example, in `css` property).
+   */
   styleExtensions: ['.css', '.pcss', '.postcss', '.styl', '.stylus', '.scss', '.sass', '.less'],
 
+  /**
+   * You can improve your DX by defining additional aliases to access custom directories
+   * within your JavaScript and CSS.
+   *
+   * **Note**: Within a webpack context (image sources, CSS - but not JavaScript) you _must_ access
+   * your alias by prefixing it with `~`.
+   *
+   * **Note**: If you are using TypeScript and want to use the alias you define within
+   * your TypeScript files, you will need to add the aliases to your `paths` object within `tsconfig.json` .
+   *
+   * @example
+   * ```js
+   * import { resolve } from 'path'
+   * export default {
+   *   alias: {
+   *     'images': resolve(__dirname, './assets/images'),
+   *     'style': resolve(__dirname, './assets/style'),
+   *     'data': resolve(__dirname, './assets/other/data')
+   *   }
+   * }
+   * ```
+   *
+   * ```html
+   * <template>
+   *   <img src="~images/main-bg.jpg">
+   * </template>
+   *
+   * <script>
+   * import data from 'data/test.json'
+   * </script>
+   *
+   * <style>
+   * // Uncomment the below
+   * //@import '~style/variables.scss';
+   * //@import '~style/utils.scss';
+   * //@import '~style/base.scss';
+   * body {
+   *   background-image: url('~images/main-bg.jpg');
+   * }
+   * </style>
+   * ```
+   */
   alias: {
     $resolve: (val, get) => ({
       '~~': get('rootDir'),
@@ -124,8 +454,30 @@ export default {
     })
   },
 
+  /**
+   * Pass options directly to `node-ignore` (which is used by Nuxt to ignore files).
+   *
+   * @see [node-ignore](https://github.com/kaelzhang/node-ignore)
+   *
+   * @example
+   * ```js
+   * ignoreOptions: {
+   *   ignorecase: false
+   * }
+   * ```
+   */
   ignoreOptions: undefined,
+
+  /**
+   * Any file in `pages/`, `layouts/`, `middleware/` or `store/` will be ignored during
+   * building if its filename starts with the prefix specified by `ignorePrefix`.
+   */
   ignorePrefix: '-',
+
+  /**
+   * More customizable than `ignorePrefix`: all files matching glob patterns specified
+   * inside the `ignore` array will be ignored in building.
+   */
   ignore: {
     $resolve: (val, get) => [
       '**/*.test.*',
@@ -134,28 +486,135 @@ export default {
     ].concat(val).filter(Boolean)
   },
 
+  /**
+   * The watch property lets you watch custom files for restarting the server.
+   *
+   * `chokidar` is used to set up the watchers. To learn more about its pattern
+   * options, see chokidar documentation.
+   *
+   * @see [chokidar](https://github.com/paulmillr/chokidar#api)
+   *
+   * @example
+   * ```js
+   * watch: ['~/custom/*.js']
+   * ```
+   */
   watch: {
     $resolve: (val, get) => [].concat(val, get('_nuxtConfigFiles')).filter(Boolean)
   },
 
+  /**
+   * The watchers property lets you overwrite watchers configuration in your `nuxt.config`.
+   */
   watchers: {
+    /** An array of event types, which, when received, will cause the watcher to restart. */
     rewatchOnRawEvents: undefined,
+    /**
+     * `watchOptions` to pass directly to webpack.
+     *
+     * @see [webpack@4 watch options](https://v4.webpack.js.org/configuration/watch/#watchoptions).
+     *  */
     webpack: {
       aggregateTimeout: 1000
     },
+    /**
+     * Options to pass directly to `chokidar`.
+     *
+     * @see [chokidar](https://github.com/paulmillr/chokidar#api)
+     */
     chokidar: {
       ignoreInitial: true
     }
   },
 
+  /**
+   * Your preferred code editor to launch when debugging.
+   *
+   * @see [documentation](https://github.com/yyx990803/launch-editor#supported-editors)
+   */
   editor: undefined,
 
+  /**
+   * Hooks are listeners to Nuxt events that are typically used in modules, but are also available in `nuxt.config`.
+   *
+   * Internally, hooks follow a naming pattern using colons (e.g., build:done).
+   *
+   * For ease of configuration, you can also structure them as an hierarchical object in `nuxt.config` (as below).
+   *
+   * @example
+   * ```js
+   * import fs from 'fs'
+   * import path from 'path'
+   * export default {
+   *   hooks: {
+   *     build: {
+   *       done(builder) {
+   *         const extraFilePath = path.join(
+   *           builder.nuxt.options.buildDir,
+   *           'extra-file'
+   *         )
+   *         fs.writeFileSync(extraFilePath, 'Something extra')
+   *       }
+   *     }
+   *   }
+   * }
+   * ```
+   */
   hooks: null,
 
+  /**
+   * Runtime config allows passing dynamic config and environment variables to the Nuxt app context.
+   *
+   * It is added to the Nuxt payload so there is no need to rebuild to update your configuration in
+   * development or if your application is served by the Nuxt server. (For static sites you will still
+   * need to regenerate your site to see changes.)
+   *
+   * The value of this object is accessible from server only using `$config`.
+   *
+   * It will override `publicRuntimeConfig` on the server-side.
+   *
+   * It should hold _private_ environment variables (that should not be exposed on the frontend).
+   * This could include a reference to your API secret tokens.
+   *
+   * @example
+   * ```js
+   * export default {
+   *   privateRuntimeConfig: {
+   *     apiSecret: process.env.API_SECRET
+   *   }
+   * }
+   * ```
+   */
   privateRuntimeConfig: {},
+
+  /**
+   * Runtime config allows passing dynamic config and environment variables to the Nuxt app context.
+   *
+   * It is added to the Nuxt payload so there is no need to rebuild to update your configuration in
+   * development or if your application is served by the Nuxt server. (For static sites you will still
+   * need to regenerate your site to see changes.)
+   *
+   * The value of this object is accessible from both client and server using `$config`. It should hold env
+   * variables that are _public_ as they will be accessible on the frontend. This could include a
+   * reference to your public URL.
+   *
+   * @example
+   * ```js
+   * export default {
+   *   publicRuntimeConfig: {
+   *     baseURL: process.env.BASE_URL || 'https://nuxtjs.org'
+   *   }
+   * }
+   * ```
+   */
   publicRuntimeConfig: {
     app: {
       $resolve: (val, get) => ({ ...get('app'), ...(val || {}) })
     }
-  }
+  },
+
+  /**
+   * Enable vite mode.
+   */
+  vite: false
 }
diff --git a/packages/kit/src/config/schema/_internal.ts b/packages/kit/src/config/schema/_internal.ts
index ffe161a3a9..2f8a4913f5 100644
--- a/packages/kit/src/config/schema/_internal.ts
+++ b/packages/kit/src/config/schema/_internal.ts
@@ -1,13 +1,22 @@
 export default {
+  /** @private */
   _majorVersion: 2,
+  /** @private */
   _legacyGenerate: false,
+  /** @private */
   _start: false,
+  /** @private */
   _build: false,
+  /** @private */
   _generate: false,
+  /** @private */
   _cli: false,
+  /** @private */
   _requiredModules: {},
+  /** @private */
   _nuxtConfigFile: undefined,
+  /** @private */
   _nuxtConfigFiles: [],
-  appDir: '',
-  vite: false
+  /** @private */
+  appDir: ''
 }
diff --git a/packages/kit/src/config/schema/build.ts b/packages/kit/src/config/schema/build.ts
index b31302a5b8..015850012a 100644
--- a/packages/kit/src/config/schema/build.ts
+++ b/packages/kit/src/config/schema/build.ts
@@ -2,26 +2,171 @@ import env from 'std-env'
 import { hasProtocol } from 'ufo'
 
 export default {
+  /**
+   * Suppresses most of the build output log.
+   *
+   * It is enabled by default when a CI or test environment is detected.
+   *
+   * @see [std-env](https://github.com/unjs/std-env)
+   */
   quiet: Boolean(env.ci || env.test),
+
+  /**
+   * Nuxt uses `webpack-bundle-analyzer` to visualize your bundles and how to optimize them.
+   *
+   * This option is normally enabled by the CLI argument `--analyze`.
+   *
+   * Set to `true` to enable bundle analysis, or pass [an object with options](https://github.com/webpack-contrib/webpack-bundle-analyzer#options-for-plugin).
+   *
+   * @example
+   * ```js
+   * analyze: {
+   *   analyzerMode: 'static'
+   * }
+   * ```
+   */
   analyze: false,
+
+  /**
+   * Enable the profiler in webpackbar.
+   *
+   * It is normally enabled by CLI argument `--profile`.
+   *
+   * @see [webpackbar](https://github.com/unjs/webpackbar#profile)
+   */
   profile: process.argv.includes('--profile'),
+
+  /**
+   * Enables Common CSS Extraction using
+   * [Vue Server Renderer guidelines](https://ssr.vuejs.org/guide/css.html).
+   *
+   * Using [extract-css-chunks-webpack-plugin](https://github.com/faceyspacey/extract-css-chunks-webpack-plugin/) under the hood, your CSS will be extracted
+   * into separate files, usually one per component. This allows caching your CSS and
+   * JavaScript separately and is worth trying if you have a lot of global or shared CSS.
+   *
+   * @example
+   * ```js
+   * extractCSS: true,
+   * // or
+   * extractCSS: {
+   *   ignoreOrder: true
+   * }
+   * ```
+   *
+   * If you want to extract all your CSS to a single file, there is a workaround for this.
+   * However, note that it is not recommended to extract everything into a single file.
+   * Extracting into multiple CSS files is better for caching and preload isolation. It
+   * can also improve page performance by downloading and resolving only those resources
+   * that are needed.
+   *
+   * @example
+   * ```js
+   * extractCSS: true,
+   * optimization: {
+   *   splitChunks: {
+   *     cacheGroups: {
+   *       styles: {
+   *         name: 'styles',
+   *         test: /\.(css|vue)$/,
+   *         chunks: 'all',
+   *         enforce: true
+   *       }
+   *     }
+   *   }
+   * }
+   * ```
+   */
   extractCSS: false,
+
+  /**
+   * Enables CSS source map support (defaults to true in development)
+   */
   cssSourceMap: {
     $resolve: (val, get) => val ?? get('dev')
   },
+
+  /**
+   * Creates special webpack bundle for SSR renderer. It is normally not necessary to change this value.
+   */
   ssr: undefined,
+
+  /**
+   * Enable [thread-loader](https://github.com/webpack-contrib/thread-loader#thread-loader) when building app with webpack.
+   *
+   * @warning This is an unstable feature.
+   */
   parallel: {
     $resolve: (val, get) => get('build.extractCSS') ? false : Boolean(val)
   },
+
+  /**
+   * Enable caching for [`terser-webpack-plugin`](https://github.com/webpack-contrib/terser-webpack-plugin#options)
+   * and [`cache-loader`](https://github.com/webpack-contrib/cache-loader#cache-loader)
+   *
+   * @warning This is an unstable feature.
+   */
   cache: false,
+
+  /**
+   * Inline server bundle dependencies
+   *
+   * This mode bundles `node_modules` that are normally preserved as externals in the server build.
+   *
+   * @warning Runtime dependencies (modules, `nuxt.config`, server middleware and the static directory) are not bundled.
+   * This feature only disables use of [webpack-externals](https://webpack.js.org/configuration/externals/) for server-bundle.
+   *
+   * @note You can enable standalone bundling by passing `--standalone` via the command line.
+   *
+   * @see [context](https://github.com/nuxt/nuxt.js/pull/4661)
+   */
   standalone: false,
+
+  /**
+   * If you are uploading your dist files to a CDN, you can set the publicPath to your CDN.
+   *
+   * @note This is only applied in production.
+   *
+   * The value of this property at runtime will override the configuration of an app that
+   * has already been built.
+   *
+   * @example
+   * ```js
+   * build: {
+   *   publicPath: process.env.PUBLIC_PATH || 'https://cdn.nuxtjs.org'
+   * }
+   * ```
+   * */
   publicPath: {
     $resolve: (val, get) => {
       if (hasProtocol(val, true) && get('dev')) { val = null }
       return (val || '/_nuxt/').replace(/([^/])$/, '$1/')
     }
   },
+
+  /**
+   * The polyfill library to load to provide URL and URLSearchParams.
+   *
+   * Defaults to `'url'` ([see package](https://www.npmjs.com/package/url)).
+   */
   serverURLPolyfill: 'url',
+
+  /**
+   * Customize bundle filenames.
+   *
+   * To understand a bit more about the use of manifests, take a look at [this webpack documentation](https://webpack.js.org/guides/code-splitting/).
+   *
+   * @note Be careful when using non-hashed based filenames in production
+   * as most browsers will cache the asset and not detect the changes on first load.
+   *
+   * This example changes fancy chunk names to numerical ids:
+   *
+   * @example
+   * ```js
+   * filenames: {
+   *   chunk: ({ isDev }) => (isDev ? '[name].js' : '[id].[contenthash].js')
+   * }
+   * ```
+   */
   filenames: {
     app: ({ isDev, isModern }) => isDev ? `[name]${isModern ? '.modern' : ''}.js` : `[contenthash:7]${isModern ? '.modern' : ''}.js`,
     chunk: ({ isDev, isModern }) => isDev ? `[name]${isModern ? '.modern' : ''}.js` : `[contenthash:7]${isModern ? '.modern' : ''}.js`,
@@ -30,6 +175,10 @@ export default {
     font: ({ isDev }) => isDev ? '[path][name].[ext]' : 'fonts/[name].[contenthash:7].[ext]',
     video: ({ isDev }) => isDev ? '[path][name].[ext]' : 'videos/[name].[contenthash:7].[ext]'
   },
+
+  /**
+   * Customize the options of Nuxt's integrated webpack loaders.
+   */
   loaders: {
     $resolve: (val, get) => {
       const styleLoaders = [
@@ -78,17 +227,72 @@ export default {
     stylus: {},
     vueStyle: {}
   },
+
+  /**
+   * @deprecated  Use [style-resources-module](https://github.com/nuxt-community/style-resources-module/)
+   */
   styleResources: {},
+
+  /**
+   * Add webpack plugins.
+   *
+   * @example
+   * ```js
+   * import webpack from 'webpack'
+   * import { version } from './package.json'
+   * // ...
+   * plugins: [
+   *   new webpack.DefinePlugin({
+   *     'process.VERSION': version
+   *   })
+   * ]
+   * ```
+   */
   plugins: [],
+
+  /**
+   * Terser plugin options.
+   *
+   * Set to false to disable this plugin, or pass an object of options.
+   *
+   * @see [terser-webpack-plugin documentation](https://github.com/webpack-contrib/terser-webpack-plugin)
+   *
+   * @note Enabling sourceMap will leave `//# sourceMappingURL` linking comment at
+   * the end of each output file if webpack `config.devtool` is set to `source-map`.
+   */
   terser: {},
+
+  /**
+   * Enables the [HardSourceWebpackPlugin](https://github.com/mzgoddard/hard-source-webpack-plugin) for improved caching.
+   *
+   * @warning unstable
+   */
   hardSource: false,
+
+  /**
+   * Hard-replaces `typeof process`, `typeof window` and `typeof document` to tree-shake bundle.
+   */
   aggressiveCodeRemoval: false,
+
+  /**
+   * OptimizeCSSAssets plugin options.
+   *
+   * Defaults to true when `extractCSS` is enabled.
+   *
+   * @see [optimize-css-assets-webpack-plugin documentation](https://github.com/NMFR/optimize-css-assets-webpack-plugin).
+   */
   optimizeCSS: {
     $resolve: (val, get) => val ?? (get('build.extractCSS') ? {} : false)
   },
+
+  /**
+   * Configure [webpack optimization](https://webpack.js.org/configuration/optimization/).
+   */
   optimization: {
     runtimeChunk: 'single',
+    /** Set minimize to false to disable all minimizers. (It is disabled in development by default) */
     minimize: { $resolve: (val, get) => val ?? get('dev') },
+    /** You can set minimizer to a customized array of plugins. */
     minimizer: undefined,
     splitChunks: {
       chunks: 'all',
@@ -96,30 +300,126 @@ export default {
       cacheGroups: {}
     }
   },
+
+  /**
+   * Whether to split code for `layout`, `pages` and `commons` chunks.
+   *
+   * Commons libs include `vue`, `vue-loader`, `vue-router`, `vuex`, etc.
+   */
   splitChunks: {
     layouts: false,
     pages: true,
     commons: true
   },
+
+  /**
+   * Nuxt will automatically detect the current version of `core-js` in your project (`'auto'`),
+   * or you can specify which version you want to use (`2` or `3`).
+   */
   corejs: 'auto',
+
+  /**
+   * Customize your Babel configuration.
+   *
+   * See [babel-loader options](https://github.com/babel/babel-loader#options) and
+   * [babel options](https://babeljs.io/docs/en/options).
+   *
+   * @note `.babelrc` is ignored by default.
+   */
   babel: {
     configFile: false,
     babelrc: false,
+    /**
+     * The Babel presets to be applied.
+     *
+     * **Note**: The presets configured here will be applied to both the client and the server
+     * build. The target will be set by Nuxt accordingly (client/server). If you want to configure
+     * the preset differently for the client or the server build, please use presets as a function.
+     *
+     * **Warning**: It is highly recommended to use the default preset instead customizing.
+     *
+     * @example
+     * ```js
+     * presets({ isServer }, [ preset, options ]) {
+     *   // change options directly
+     *   options.targets = isServer ? ... :  ...
+     *   options.corejs = ...
+     *   // return nothing
+     * }
+     * ```
+     *
+     * @example
+     * ```js
+     * presets({ isServer }, [preset, options]) {
+     *   return [
+     *     [
+     *       preset,
+     *       {
+     *         targets: isServer ? ... :  ...,
+     *         ...options
+     *       }
+     *     ],
+     *     [
+     *       // Other presets
+     *     ]
+     *   ]
+     * }
+     * ```
+     */
     presets: {},
     cacheDirectory: {
       $resolve: (val, get) => val ?? get('dev')
     }
   },
+
+  /**
+   * If you want to transpile specific dependencies with Babel, you can add them here.
+   * Each item in transpile can be a package name, a function, a string or regex object matching the
+   * dependency's file name.
+   *
+   * Tou can also use a function to conditionally transpile, the function will receive a object ({ isDev, isServer, isClient, isModern, isLegacy }).
+   *
+   * @example
+   * ```js
+    transpile: [({ isLegacy }) => isLegacy && 'ky']
+   * ```
+   */
   transpile: {
     $resolve: val => [].concat(val).filter(Boolean)
   },
+
+  /**
+   * Customize PostCSS Loader plugins.
+   */
   postcss: {
     preset: {
       // https://cssdb.org/#staging-process
       stage: 2
     }
   },
+
   html: {
+    /**
+     * Configuration for the html-minifier plugin used to minify HTML files created
+     * during the build process (will be applied for all modes).
+     *
+     * **Attention**: If you make changes, they won't be merged with the defaults!
+     *
+     * @example
+     * ```js
+     * minify: {
+     *   collapseBooleanAttributes: true,
+     *   decodeEntities: true,
+     *   minifyCSS: true,
+     *   minifyJS: true,
+     *   processConditionalComments: true,
+     *   removeEmptyAttributes: true,
+     *   removeRedundantAttributes: true,
+     *   trimCustomFragments: true,
+     *   useShortDoctype: true
+     * }
+     * ```
+     */
     minify: {
       collapseBooleanAttributes: true,
       decodeEntities: true,
@@ -133,13 +433,46 @@ export default {
     }
   },
 
+  /** Allows setting a different app template (other than `@nuxt/vue-app`) */
   template: undefined,
+  /**
+   * You can provide your own templates which will be rendered based
+   * on Nuxt configuration. This feature is specially useful for using with modules.
+   *
+   * Templates are rendered using [`lodash.template`](https://lodash.com/docs/4.17.15#template).
+   *
+   * @example
+   * ```js
+   * templates: [
+   *   {
+   *     src: '~/modules/support/plugin.js', // `src` can be absolute or relative
+   *     dst: 'support.js', // `dst` is relative to project `.nuxt` dir
+   *     options: {
+   *       // Options are provided to template as `options` key
+   *       live_chat: false
+   *     }
+   *   }
+   * ]
+   * ```
+   */
   templates: [],
 
+  /**
+   * You can provide your custom files to watch and regenerate after changes.
+   *
+   * This feature is specially useful for using with modules.
+   *
+   * @example
+   * ```js
+    watch: ['~/.nuxt/support.js']
+   * ```
+   */
   watch: [],
+  /** See [webpack-dev-middleware](https://github.com/webpack/webpack-dev-middleware) for available options. */
   devMiddleware: {
     stats: 'none'
   },
+  /** See [webpack-hot-middleware](https://github.com/webpack-contrib/webpack-hot-middleware) for available options. */
   hotMiddleware: {},
 
   vendor: {
@@ -148,17 +481,22 @@ export default {
     }
   },
 
+  /** Set to `'none'` or `false` to disable stats printing out after a build. */
   stats: {
-    $resolve: (val, get) => (val === 'none' || get('build.quite')) ? false : val,
+    $resolve: (val, get) => (val === 'none' || get('build.quiet')) ? false : val,
     excludeAssets: [
       /.map$/,
       /index\..+\.html$/,
       /vue-ssr-(client|modern)-manifest.json/
     ]
   },
+  /** Set to `false` to disable the overlay provided by [FriendlyErrorsWebpackPlugin](https://github.com/nuxt/friendly-errors-webpack-plugin) */
   friendlyErrors: true,
+  /** Additional extensions (beyond `['vue', 'js']` to support in `pages/`, `layouts/`, `middleware/`, etc.) */
   additionalExtensions: [],
+  /** Filters to hide build warnings. */
   warningIgnoreFilters: [],
 
+  /** Set to true to scan files within symlinks in the build (such as within `pages/`). */
   followSymlinks: false
 }
diff --git a/packages/kit/src/config/schema/cli.ts b/packages/kit/src/config/schema/cli.ts
index 0e79115bd1..d3bef5179b 100644
--- a/packages/kit/src/config/schema/cli.ts
+++ b/packages/kit/src/config/schema/cli.ts
@@ -1,4 +1,11 @@
 export default {
+  /**
+   * Add a message to the CLI banner by adding a string to this array.
+   */
   badgeMessages: [],
+
+  /**
+   * Change the color of the 'Nuxt.js' title in the CLI banner.
+   */
   bannerColor: 'green'
 }
diff --git a/packages/kit/src/config/schema/generate.ts b/packages/kit/src/config/schema/generate.ts
index a9caa545ba..f7962361ce 100644
--- a/packages/kit/src/config/schema/generate.ts
+++ b/packages/kit/src/config/schema/generate.ts
@@ -2,28 +2,153 @@ import { resolve } from 'path'
 import { joinURL } from 'ufo'
 
 export default {
+  /**
+   * Directory name that holds all the assets and generated pages for a `static` build.
+   */
   dir: {
     $resolve: (val = 'dist', get) => resolve(get('rootDir'), val)
   },
+
+  /**
+   * The routes to generate.
+   *
+   * If you are using the crawler, this will be only the starting point for route generation.
+   * This is often necessary when using dynamic routes.
+   *
+   * It can be an array or a function.
+   *
+   * @example
+   * ```js
+   * routes: ['/users/1', '/users/2', '/users/3']
+   * ```
+   *
+   * You can pass a function that returns a promise or a function that takes a callback. It should
+   * return an array of strings or objects with `route` and (optional) `payload` keys.
+   *
+   * @example
+   * ```js
+   * async routes() {
+   *   const res = await axios.get('https://my-api/users')
+   *   return res.data.map(user => ({ route: '/users/' + user.id, payload: user }))
+   * }
+   * // or
+   * routes(callback) {
+   *   axios
+   *     .get('https://my-api/users')
+   *     .then(res => {
+   *       const routes = res.data.map(user => '/users/' + user.id)
+   *       callback(null, routes)
+   *     })
+   *     .catch(callback)
+   * }
+   * ```
+   *
+   * If `routes()` returns a payload, it can be accessed from the Nuxt context.
+   * @example
+   * ```js
+   * async asyncData ({ params, error, payload }) {
+   *   if (payload) return { user: payload }
+   *   else return { user: await backend.fetchUser(params.id) }
+   * }
+   * ```
+   */
   routes: [],
+
+  /**
+   * An array of string or regular expressions that will prevent generation
+   * of routes matching them. The routes will still be accessible when `fallback` is set.
+   */
   exclude: [],
+
+  /** The number of routes that are generated concurrently in the same thread. */
   concurrency: 500,
+
+  /**
+   * Interval in milliseconds between two render cycles to avoid flooding a potential
+   * API with calls.
+   */
   interval: 0,
+
+  /**
+   * Set to `false` to disable creating a directory + `index.html` for each route.
+   *
+   * @example
+   * ```bash
+   * # subFolders: true
+   * -| dist/
+   * ---| index.html
+   * ---| about/
+   * -----| index.html
+   * ---| products/
+   * -----| item/
+   * -------| index.html
+   *
+   * # subFolders: false
+   * -| dist/
+   * ---| index.html
+   * ---| about.html
+   * ---| products/
+   * -----| item.html
+   * ```
+   */
   subFolders: true,
+
+  /**
+   * The path to the fallback HTML file.
+   *
+   * Set this as the error page in your static server configuration, so that unknown
+   * routes can be rendered (on the client-side) by Nuxt.
+   *
+   * * If unset or set to a falsy value, the name of the fallback HTML file will be `200.html`.
+   * * If set to true, the filename will be `404.html`.
+   * * If you provide a string as a value, it will be used instead.
+   *
+   * **Note**: Multiple services (e.g. Netlify) detect a `404.html` automatically. If
+   * you configure your web server on your own, please consult its documentation
+   * to find out how to set up an error page (and set it to the 404.html file)
+   */
   fallback: { $resolve: val => val === true ? '400.html' : (val || '200.html') },
+
+  /**
+   * Set to `false` to disable generating pages discovered through crawling relative
+   * links in generated pages.
+   */
   crawler: true,
+
+  /** Set to `false` to disable generating a `manifest.js` with a list of all generated pages. */
   manifest: true,
+
+  /** Set to `false` to disable generating a `.nojekyll` file (which aids compatibility with GitHub Pages). */
   nojekyll: true,
+
+  /**
+   * Configure the cache (used with `static` target to avoid rebuilding when no files have changed).
+   *
+   * Set to `false` to disable completely.
+   */
   cache: {
+    /** An array of files or directories to ignore. (It can also be a function that returns an array.) */
     ignore: [],
+    /**
+     * Options to pass to [`globby`](https://github.com/sindresorhus/globby), which
+     * is used to generate a 'snapshot' of the source files.
+     */
     globbyOptions: {
       gitignore: true
     }
   },
+
   staticAssets: {
+    /** The directory underneath `/_nuxt/`, where static assets (payload, state and manifest files) will live. */
     dir: 'static',
+    /**
+     * The full path to the directory underneath `/_nuxt/` where static assets
+     * (payload, state and manifest files) will live.
+     */
     base: { $resolve: (val, get) => val || joinURL(get('app.assetsPath'), get('generate.dir')) },
+    /** The full path to the versioned directory where static assets for the current buidl are located. */
     versionBase: { $resolve: (val, get) => val || joinURL(get('generate.base'), get('generate.version')) },
+    /** A unique string to uniquely identify payload versions (defaults to the current timestamp).  */
     version: { $resolve: val => val || (String(Math.round(Date.now() / 1000))) }
   }
 }
diff --git a/packages/kit/src/config/schema/messages.ts b/packages/kit/src/config/schema/messages.ts
index ad1ff51de1..530740137d 100644
--- a/packages/kit/src/config/schema/messages.ts
+++ b/packages/kit/src/config/schema/messages.ts
@@ -1,10 +1,18 @@
 export default {
+  /** The text that displays on the Nuxt loading indicator when `ssr: false`. */
   loading: 'Loading...',
+  /** The 404 text on the default Nuxt error page. */
   error_404: 'This page could not be found',
+  /** The text to display on the default Nuxt error page when there has been a server error. */
   server_error: 'Server error',
+  /** The text (linked to nuxtjs.org) that appears on the built-in Nuxt error page. */
   nuxtjs: 'Nuxt',
+  /** The text (linked to the home page) that appears on the built-in Nuxt error page. */
   back_to_home: 'Back to the home page',
+  /** The message that will display on a white screen if the built-in Nuxt error page can't be rendered. */
   server_error_details: 'An error occurred in the application and your page could not be served. If you are the application owner, check your logs for details.',
+  /** The default error title (if there isn't a specific error message) on the built-in Nuxt error page. */
   client_error: 'Error',
+  /** The error message (in debug mode) on the built-in Nuxt error page. */
   client_error_details: 'An error occurred while rendering the page. Check developer tools console for details.'
 }
diff --git a/packages/kit/src/config/schema/render.ts b/packages/kit/src/config/schema/render.ts
index 2c09cfc65b..4bdfada308 100644
--- a/packages/kit/src/config/schema/render.ts
+++ b/packages/kit/src/config/schema/render.ts
@@ -1,52 +1,269 @@
 export default {
+  /**
+   * Use this option to customize the Vue SSR bundle renderer.
+   * This option is skipped if `ssr: false`.
+   *
+   * Read [docs for Vue 2](https://ssr.vuejs.org/api/#renderer-options) here.
+   */
   bundleRenderer: {
     shouldPrefetch: () => false,
     shouldPreload: (_fileWithoutQuery, asType) => ['script', 'style'].includes(asType),
-    /**
-     * enabled by default for development
-     */
+    /** enabled by default for development */
     runInNewContext: { $resolve: (val, get) => val ?? get('dev') }
   },
+
+  /**
+   * Configure the crossorigin attribute on `<link rel="stylesheet">` and `<script>`
+   * tags in generated HTML. [More information](https://developer.mozilla.org/en-US/docs/Web/HTML/Attributes/crossorigin).
+   */
   crossorigin: undefined,
+
+  /**
+   * Adds prefetch and preload links for faster initial page load time.
+   * You probably don't want to disable this option unless you have many pages and routes.
+   */
   resourceHints: true,
+
+  /**
+   * Whether to enable rendering of HTML - either dynamically (in server mode) or at generate time.
+   *
+   * This option is automatically set based on global ssr value if not provided.
+   * This can be useful to dynamically enable/disable SSR on runtime after image builds
+   * (with docker for example).
+   */
   ssr: undefined,
+
+  /**
+   * Forward server-side logs to the browser for better debugging (only available in development)
+   *
+   * Set to `collapsed` to collapse the logs, or false to disable.
+   */
   ssrLog: { $resolve: (val, get) => get('dev') ? Boolean(val) : false },
+
+  /**
+   * Configuration for HTTP2 push headers
+   */
   http2: {
+    /** Set to true to enable HTTP2 push headers */
     push: false,
+    /** @deprecated */
     shouldPush: null,
+    /**
+     * You can control what links to push using this function. It receives `req`,
+     * `res`, `publicPath` and a `preloadFiles` array.
+     *
+     * You can add your own assets to the array as well. Using `req` and `res`
+     * you can decide what links to push based on the request headers, for example
+     * using the cookie with application version.
+     *
+     * Assets will be joined together with `,` and passed as a single `Link` header.
+     *
+     * @example
+     * ```js
+     * pushAssets: (req, res, publicPath, preloadFiles) =>
+     *   preloadFiles
+     *     .filter(f => f.asType === 'script' && f.file === 'runtime.js')
+     *     .map(f => `<${publicPath}${f.file}>; rel=preload; as=${f.asType}`)
+     * ```
+     */
     pushAssets: null
   },
+
+  /**
+   * Configure the behavior of the `static/` directory.
+   *
+   * See [serve-static docs](https://github.com/expressjs/serve-static) for possible options.
+   */
   static: {
+    /**
+     * Whether to add the router base to your static assets.
+     *
+     * **Note**: some URL rewrites might not respect the prefix.
+     *
+     * @example
+     * Assets: favicon.ico
+     * Router base: /t
+     * With `prefix: true` (default): /t/favicon.ico
+     * With `prefix: false`: /favicon.ico
+     */
     prefix: true
   },
+
+  /**
+   * Configure server compression.
+   *
+   * Set to `false` to disable compression. You can also pass an object of options
+   * for [compression middleware](https://www.npmjs.com/package/compression), or
+   * use your own middleware by passing it in directly - for example,
+   * `otherComp({ myOptions: 'example' })`.
+   */
   compressor: {
     threshold: 0
   },
+
+  /**
+   * To disable etag for pages set `etag: false`. See
+   * [etag docs](https://github.com/jshttp/etag) for possible options.
+   * You can use your own hash function by specifying etag.hash:
+   *
+   * @example
+   * ```js
+   * import { murmurHash128 } from 'murmurhash-native'
+   *
+   * export default {
+   *   render: {
+   *     etag: {
+   *       hash: html => murmurHash128(html)
+   *     }
+   *   }
+   * }
+   * ```
+   * In this example we are using `murmurhash-native`, which is faster
+   * for larger HTML body sizes. Note that the weak option is ignored
+   * when specifying your own hash function.
+   */
   etag: {
     hash: false,
     weak: false
   },
+
+  /**
+   * Use this to configure Content-Security-Policy to load external resources. [Read more](https://developer.mozilla.org/en-US/docs/Web/HTTP/CSP).
+   *
+   * Set to `true` to enable, or you can pass options to fine-tune your CSP options.
+   *
+   * **Prerequisites**:
+   * These CSP settings are only effective when using Nuxt with `mode: 'server'`
+   * to serve your SSR application.
+   *
+   * **Updating settings**:
+   * These settings are read by the Nuxt server directly from `nuxt.config.js`.
+   * This means changes to these settings take effect when the server is restarted.
+   * There is no need to rebuild the application to update CSP settings.
+   *
+   * @example
+   * ```js
+   * csp: {
+   *   hashAlgorithm: 'sha256',
+   *   policies: {
+   *     'script-src': [
+   *       'https://www.google-analytics.com',
+   *       'https://name.example.com'
+   *     ],
+   *     'report-uri': ['https://report.example.com/report-csp-violations']
+   *   },
+   *   addMeta: true
+   * }
+   * ```
+   *
+   * The following example allows Google Analytics, LogRocket.io, and Sentry.io
+   * for logging and analytic tracking.
+   *
+   * Review [this blog on Sentry.io](https://blog.sentry.io/2018/09/04/how-sentry-captures-csp-violations)
+   * To learn what tracking link you should use.
+   * @example
+   * ```js
+   * // PRIMARY_HOSTS = `loc.example-website.com`
+   * csp: {
+   *   reportOnly: true,
+   *   hashAlgorithm: 'sha256',
+   *   policies: {
+   *     'default-src': ["'self'"],
+   *     'img-src': ['https:', '*.google-analytics.com'],
+   *     'worker-src': ["'self'", `blob:`, PRIMARY_HOSTS, '*.logrocket.io'],
+   *     'style-src': ["'self'", "'unsafe-inline'", PRIMARY_HOSTS],
+   *     'script-src': [
+   *       "'self'",
+   *       "'unsafe-inline'",
+   *       PRIMARY_HOSTS,
+   *       'sentry.io',
+   *       '*.sentry-cdn.com',
+   *       '*.google-analytics.com',
+   *       '*.logrocket.io'
+   *     ],
+   *     'connect-src': [PRIMARY_HOSTS, 'sentry.io', '*.google-analytics.com'],
+   *     'form-action': ["'self'"],
+   *     'frame-ancestors': ["'none'"],
+   *     'object-src': ["'none'"],
+   *     'base-uri': [PRIMARY_HOSTS],
+   *     'report-uri': [
+   *       `https://sentry.io/api/<project>/security/?sentry_key=<key>`
+   *     ]
+   *   }
+   * }
+   * ```
+   */
   csp: {
     $resolve: (val, get) => {
       if (!val) { return false }
       return {
         hashAlgorithm: 'sha256',
         allowedSources: undefined,
+        /** Policies to be added to the response `Content-Security-Policy` HTTP header. */
         policies: undefined,
+        /**
+         * Whether to add `<meta http-equiv="Content-Security-Policy"/>` to the `<head>`.
+         * This is independent of the `csp.policies` configuration and the complete set
+         * of the defined policies will still be added to the HTTP response header.
+         *
+         * **Note** CSP hashes will not be added as `<meta>` if `script-src` policy
+         * contains 'unsafe-inline'. This is due to browsers ignoring 'unsafe-inline'
+         * if hashes are present. (Set option `unsafeInlineCompatibility` to true to
+         * disable this behavior.)
+         */
         addMeta: Boolean(get('target') === 'static'),
+        /**
+         * Set option `unsafeInlineCompatibility` to true if you want both hashes and
+         * 'unsafe-inline' for CSPv1 compatibility. In that case the `<meta>` tag will
+         * still only contain the hashes of the inline `<script>` tags, and the policies
+         * defined under `csp.policies` will be used in the `Content-Security-Policy`
+         * HTTP response header.
+         */
         unsafeInlineCompatibility: false,
         reportOnly: get('debug'),
         ...val
       }
     }
   },
+
+  /**
+   * Options used for serving distribution files. Only applicable in production.
+   *
+   * See [serve-static docs](https://www.npmjs.com/package/serve-static) for possible options.
+   */
   dist: {
     index: false,
     maxAge: '1y'
   },
-  // https://github.com/nuxt/serve-placeholder
+
+  /**
+   * Configure fallback behavior for [`serve-placeholder` middleware](https://github.com/nuxt/serve-placeholder).
+   *
+   * Example of allowing `.js` extension for routing (for example, `/repos/nuxt.js`):
+   *
+   * @example
+   * ```js
+   * fallback: {
+   *   static: {
+   *     // Avoid sending 404 for these extensions
+   *     handlers: {
+   *       '.js': false
+   *     }
+   *   }
+   * }
+   * ```
+   */
   fallback: {
+    /**
+     * For routes matching the publicPath (`/_nuxt/*`)
+     * Disable by setting to false.
+     */
     dist: {},
+
+    /**
+     * For all other routes (`/*`)
+     * Disable by setting to false.
+     */
     static: {
       skipUnknown: true,
       handlers: {
diff --git a/packages/kit/src/config/schema/router.ts b/packages/kit/src/config/schema/router.ts
index 2db41b6bbb..0568cabe21 100644
--- a/packages/kit/src/config/schema/router.ts
+++ b/packages/kit/src/config/schema/router.ts
@@ -1,31 +1,135 @@
 import { normalizeURL, withTrailingSlash } from 'ufo'
 
 export default {
+  /**
+   * Configure the router mode.
+   *
+   * For server-side rendering it is not recommended to change it.
+   */
   mode: 'history',
+
+  /**
+   * The base URL of the app. For example, if the entire single page application is
+   * served under /app/, then base should use the value '/app/'.
+   *
+   * This can be useful if you need to serve Nuxt as a different context root, from
+   * within a bigger web site.
+   */
   base: {
     $resolve: (val = '/') => withTrailingSlash(normalizeURL(val))
   },
+
+  /** @private */
   _routerBaseSpecified: {
     $resolve: (_val, get) => typeof get('router.base') === 'string'
   },
+
   routes: [],
+
+  /**
+   * This allows changing the separator between route names that Nuxt uses.
+   *
+   * Imagine we have the page file `pages/posts/_id.vue`. Nuxt will generate the
+   * route name programmatically, in this case `posts-id`. If you change the routeNameSplitter
+   * config to `/` the name will change to `posts/id`.
+   */
   routeNameSplitter: '-',
+
+  /**
+   * Set the default(s) middleware for every page of the application.
+   */
   middleware: {
     $resolve: val => Array.isArray(val) ? val : [val].filter(Boolean)
   },
+
+  /**
+   * Globally configure `<nuxt-link>` default active class.
+   */
   linkActiveClass: 'nuxt-link-active',
+
+  /**
+   * Globally configure `<nuxt-link>` default exact active class.
+   */
   linkExactActiveClass: 'nuxt-link-exact-active',
+
+  /**
+   * Globally configure `<nuxt-link>` default prefetch class (feature disabled by default)
+   */
   linkPrefetchedClass: false,
+
+  /**
+   * You can pass a function to extend the routes created by Nuxt.
+   *
+   * @example
+   * ```js
+   * extendRoutes(routes, resolve) {
+   *   routes.push({
+   *   name: 'custom',
+   *   path: '*',
+   *   component: resolve(__dirname, 'pages/404.vue')
+   * })
+   * ```
+   */
   extendRoutes: null,
+
+  /**
+   * The `scrollBehavior` option lets you define a custom behavior for the scroll
+   * position between the routes. This method is called every time a page is
+   * rendered. To learn more about it.
+   *
+   * @see [vue-router `scrollBehavior` documentation](https://router.vuejs.org/guide/advanced/scroll-behavior.html)
+   */
   scrollBehavior: {
     $schema: {
       deprecated: 'router.scrollBehavior` property is deprecated in favor of using `~/app/router.scrollBehavior.js` file, learn more: https://nuxtjs.org/api/configuration-router#scrollbehavior'
     }
   },
+
+  /**
+   * Provide custom query string parse function. Overrides the default.
+   */
   parseQuery: false,
+
+  /**
+   * Provide custom query string stringify function. Overrides the default.
+   */
   stringifyQuery: false,
+
+  /**
+   * Controls whether the router should fall back to hash mode when the browser
+   * does not support history.pushState but mode is set to history.
+   *
+   * Setting this to false essentially makes every router-link navigation a full
+   * page refresh in IE9. This is useful when the app is server-rendered and needs
+   * to work in IE9, because a hash mode URL does not work with SSR.
+   */
   fallback: false,
+
+  /**
+   * Configure `<nuxt-link>` to prefetch the code-splitted page when detected within
+   * the viewport. Requires [IntersectionObserver](https://developer.mozilla.org/en-US/docs/Web/API/Intersection_Observer_API) to be supported (see [Caniuse](https://caniuse.com/intersectionobserver)).
+   */
   prefetchLinks: true,
+
+  /**
+   * When using nuxt generate with target: 'static', Nuxt will generate a
+   * payload.js for each page.
+   *
+   * With this option enabled, Nuxt will automatically prefetch the payload of the
+   * linked page when the <nuxt-link> is visible in the viewport, making instant navigation.
+   */
   prefetchPayloads: true,
+
+  /**
+   * If this option is set to true, trailing slashes will be appended to every
+   * route. If set to false, they'll be removed.
+   *
+   * **Attention**: This option should not be set without preparation and has to
+   * be tested thoroughly. When setting `trailingSlash` to something else than
+   * undefined, the opposite route will stop working. Thus 301 redirects should
+   * be in place and your internal linking has to be adapted correctly. If you set
+   * `trailingSlash` to true, then only example.com/abc/ will work but not
+   * example.com/abc. On false, it's vice-versa
+   */
   trailingSlash: undefined
 }
diff --git a/packages/kit/src/config/schema/server.ts b/packages/kit/src/config/schema/server.ts
index a476ab909a..80a49e1881 100644
--- a/packages/kit/src/config/schema/server.ts
+++ b/packages/kit/src/config/schema/server.ts
@@ -1,7 +1,27 @@
 export default {
+  /**
+   * Whether to enable HTTPS.
+   *
+   * @example
+   * ```js
+   * https: {
+   *   key: fs.readFileSync(path.resolve(__dirname, 'server.key')),
+   *   cert: fs.readFileSync(path.resolve(__dirname, 'server.crt'))
+   * }
+   * ```
+   */
   https: false,
   port: process.env.NUXT_PORT || process.env.PORT || process.env.npm_package_config_nuxt_port || 3000,
   host: process.env.NUXT_HOST || process.env.HOST || process.env.npm_package_config_nuxt_host || 'localhost',
   socket: process.env.UNIX_SOCKET || process.env.npm_package_config_unix_socket,
+
+  /**
+   * Enabling timing adds a middleware to measure the time elapsed during
+   * server-side rendering and adds it to the headers as 'Server-Timing'.
+   *
+   * Apart from true/false, this can be an object for providing options.
+   * Currently, only `total` is supported (which directly tracks the whole
+   * time spent on server-side rendering.
+   */
   timing: (val: any) => val ? ({ total: true, ...val }) : false
 }
diff --git a/packages/kit/src/module/container.ts b/packages/kit/src/module/container.ts
index 3b76c858d7..6e2d08b7fb 100644
--- a/packages/kit/src/module/container.ts
+++ b/packages/kit/src/module/container.ts
@@ -13,6 +13,7 @@ import {
   extendRoutes
 } from './utils'
 
+/** Legacy ModuleContainer for backwards compatibility with existing Nuxt 2 modules. */
 export class ModuleContainer {
   nuxt: Nuxt
   options: NuxtOptions
@@ -27,47 +28,88 @@ export class ModuleContainer {
     return nuxtCtx.call(this.nuxt, () => fn(...args))
   }
 
+  /**
+   * Returns a resolved promise immediately.
+   *
+   * @deprecated
+   */
   ready () {
     return Promise.resolve()
   }
 
+  /** @deprecated */
   addVendor () {
-    console.warn('addVendor has been deprecated')
+    console.warn('addVendor has been deprecated and has no effect.')
   }
 
+  /**
+   * Renders given template using lodash template during build into the project buildDir (`.nuxt`).
+   *
+   * If a fileName is not provided or the template is string, target file name defaults to
+   * [dirName].[fileName].[pathHash].[ext].
+   */
   addTemplate (tmpl: TemplateOpts | string) {
     return this._call(addTemplate, tmpl)
   }
 
+  /**
+   * Registers a plugin using `addTemplate` and prepends it to the plugins[] array.
+   *
+   * Note: You can use mode or .client and .server modifiers with fileName option
+   * to use plugin only in client or server side.
+   *
+   * If you choose to specify a fileName, you can configure a custom path for the
+   * fileName too, so you can choose the folder structure inside .nuxt folder in
+   * order to prevent name collisioning:
+   *
+   * @example
+   * ```js
+   * this.addPlugin({
+   *   src: path.resolve(__dirname, 'templates/foo.js'),
+   *   fileName: 'foo.server.js' // [optional] only include in server bundle
+   * })
+   * ```
+   */
   addPlugin (tmpl: PluginTemplateOpts) {
     return this._call(addPlugin, tmpl)
   }
 
+  /** Register a custom layout. If its name is 'error' it will override the default error layout. */
   addLayout (tmpl: TemplateOpts, name: string) {
     return this._call(addLayout, tmpl, name)
   }
 
+  /**
+   * Set the layout that will render Nuxt errors. It should already have been added via addLayout or addTemplate.
+   *
+   * @param dst - Path to layout file within the buildDir (`.nuxt/<dst>.vue`)
+   */
   addErrorLayout (dst: string) {
     return this._call(addErrorLayout, dst)
   }
 
+  /** Adds a new server middleware to the end of the server middleware array. */
   addServerMiddleware (middleware) {
     return this._call(addServerMiddleware, middleware)
   }
 
+  /** Allows extending webpack build config by chaining `options.build.extend` function. */
   extendBuild (fn) {
     return this._call(extendBuild, fn)
   }
 
+  /** Allows extending routes by chaining `options.build.extendRoutes` function. */
   extendRoutes (fn) {
     return this._call(extendRoutes, fn)
   }
 
-  requireModule (moduleOpts) {
+  /** `requireModule` is a shortcut for `addModule` */
+  requireModule (moduleOpts: string | [src: string, options: any]) {
     return installModule(this.nuxt, moduleOpts)
   }
 
-  addModule (moduleOpts) {
+  /** Registers a module. moduleOpts can be a string or an array ([src, options]). */
+  addModule (moduleOpts: string | [src: string, options: any]) {
     return installModule(this.nuxt, moduleOpts)
   }
 }
diff --git a/packages/kit/src/module/define.ts b/packages/kit/src/module/define.ts
index 18107a790a..5d06d26444 100644
--- a/packages/kit/src/module/define.ts
+++ b/packages/kit/src/module/define.ts
@@ -4,6 +4,10 @@ import { useNuxt, nuxtCtx } from '../nuxt'
 import type { Nuxt } from '../types/nuxt'
 import type { NuxtModule, LegacyNuxtModule, ModuleOptions } from '../types/module'
 
+/**
+ * Define a Nuxt module, automatically merging defaults with user provided options, installing
+ * any hooks that are provided, and calling an optional setup function for full control.
+ */
 export function defineNuxtModule<OptionsT extends ModuleOptions> (input: NuxtModule<OptionsT> | ((nuxt: Nuxt) => NuxtModule<OptionsT>)): LegacyNuxtModule {
   let mod: NuxtModule<OptionsT>
 
diff --git a/packages/kit/src/module/install.ts b/packages/kit/src/module/install.ts
index b0655075a1..4ce2fa4415 100644
--- a/packages/kit/src/module/install.ts
+++ b/packages/kit/src/module/install.ts
@@ -5,6 +5,7 @@ import { nuxtCtx } from '../nuxt'
 import { defineNuxtModule } from './define'
 import { ModuleContainer } from './container'
 
+/** Installs a module on a Nuxt instance. */
 export async function installModule (nuxt: Nuxt, installOpts: ModuleInstallOptions) {
   let src: ModuleSrc
   let options: ModuleOptions = {}
diff --git a/packages/kit/src/module/utils.ts b/packages/kit/src/module/utils.ts
index eea2ec4010..dbb04902b5 100644
--- a/packages/kit/src/module/utils.ts
+++ b/packages/kit/src/module/utils.ts
@@ -6,6 +6,12 @@ import { useNuxt } from '../nuxt'
 import { chainFn } from '../utils/task'
 import type { TemplateOpts, PluginTemplateOpts } from '../types/module'
 
+/**
+ * Renders given template using lodash template during build into the project buildDir (`.nuxt`).
+ *
+ * If a fileName is not provided or the template is string, target file name defaults to
+ * [dirName].[fileName].[pathHash].[ext].
+ */
 export function addTemplate (tmpl: TemplateOpts | string) {
   const nuxt = useNuxt()
 
@@ -21,7 +27,7 @@ export function addTemplate (tmpl: TemplateOpts | string) {
     throw new Error('tmpl src not found: ' + src)
   }
 
-  // Mostly for DX, some people prefers `filename` vs `fileName`
+  // Mostly for DX, some people prefer `filename` vs `fileName`
   const fileName = typeof tmpl === 'string' ? '' : tmpl.fileName || tmpl.filename
   // Generate unique and human readable dst filename if not provided
   const dst = fileName || `${basename(srcPath.dir)}.${srcPath.name}.${hash(src)}${srcPath.ext}`
@@ -37,6 +43,24 @@ export function addTemplate (tmpl: TemplateOpts | string) {
   return tmplObj
 }
 
+/**
+ * Registers a plugin using `addTemplate` and prepends it to the plugins[] array.
+ *
+ * Note: You can use mode or .client and .server modifiers with fileName option
+ * to use plugin only in client or server side.
+ *
+ * If you choose to specify a fileName, you can configure a custom path for the
+ * fileName too, so you can choose the folder structure inside .nuxt folder in
+ * order to prevent name collisioning:
+ *
+ * @example
+ * ```js
+ * addPlugin({
+ *   src: path.resolve(__dirname, 'templates/foo.js'),
+ *   fileName: 'foo.server.js' // [optional] only include in server bundle
+ * })
+ * ```
+ */
 export function addPlugin (tmpl: PluginTemplateOpts) {
   const nuxt = useNuxt()
 
@@ -53,6 +77,7 @@ export function addPlugin (tmpl: PluginTemplateOpts) {
   })
 }
 
+/** Register a custom layout. If its name is 'error' it will override the default error layout. */
 export function addLayout (tmpl: TemplateOpts, name: string) {
   const nuxt = useNuxt()
 
@@ -73,6 +98,11 @@ export function addLayout (tmpl: TemplateOpts, name: string) {
   }
 }
 
+/**
+ * Set the layout that will render Nuxt errors. It should already have been added via addLayout or addTemplate.
+ *
+ * @param dst - Path to layout file within the buildDir (`.nuxt/<dst>.vue`)
+ */
 export function addErrorLayout (dst: string) {
   const nuxt = useNuxt()
 
@@ -80,12 +110,14 @@ export function addErrorLayout (dst: string) {
   nuxt.options.ErrorPage = `~/${relativeBuildDir}/${dst}`
 }
 
+/** Adds a new server middleware to the end of the server middleware array. */
 export function addServerMiddleware (middleware) {
   const nuxt = useNuxt()
 
   nuxt.options.serverMiddleware.push(middleware)
 }
 
+/** Allows extending webpack build config by chaining `options.build.extend` function. */
 export function extendBuild (fn) {
   const nuxt = useNuxt()
 
@@ -93,6 +125,7 @@ export function extendBuild (fn) {
   nuxt.options.build.extend = chainFn(nuxt.options.build.extend, fn)
 }
 
+/** Allows extending routes by chaining `options.build.extendRoutes` function. */
 export function extendRoutes (fn) {
   const nuxt = useNuxt()
 
diff --git a/packages/kit/src/nuxt.ts b/packages/kit/src/nuxt.ts
index 6b133b297f..0a3f7a16cb 100644
--- a/packages/kit/src/nuxt.ts
+++ b/packages/kit/src/nuxt.ts
@@ -2,9 +2,28 @@ import { getContext } from 'unctx'
 import type { Nuxt } from './types/nuxt'
 import type { NuxtConfig } from './types/config'
 
+/** Direct access to the Nuxt context - see https://github.com/unjs/unctx. */
 export const nuxtCtx = getContext<Nuxt>('nuxt')
+/**
+ * Get access to Nuxt (if run within the Nuxt context) - see https://github.com/unjs/unctx.
+ *
+ * @example
+ * ```js
+ * const nuxt = useNuxt()
+ * ```
+ */
 export const useNuxt = nuxtCtx.use
 
+/**
+ * This helper serves to add the correct typings for your `nuxt.config.js`.
+ *
+ * @example
+ * ```ts
+ * import { defineNuxtConfig } from '@nuxt/kit'
+ * export default defineNuxtConfig({
+ *   // your Nuxt config
+ * })
+ */
 export function defineNuxtConfig (config: NuxtConfig) {
   return config
 }
diff --git a/packages/kit/src/types/module.ts b/packages/kit/src/types/module.ts
index 55298c86a3..945d21da3a 100644
--- a/packages/kit/src/types/module.ts
+++ b/packages/kit/src/types/module.ts
@@ -3,18 +3,26 @@ import { Nuxt } from './nuxt'
 import { NuxtHooks } from './hooks'
 
 export interface ModuleMeta {
+  /** The module name. */
   name?: string
+  /**
+   * The configuration key used within `nuxt.config` for this module's options.
+   * For example, `@nuxtjs/axios` uses `axios`.
+   */
   configKey?: string
   [key: string]: any
 }
 
+/** The options received  */
 export type ModuleOptions = Record<string, any>
 
+/** A pre-kit Nuxt module */
 export interface LegacyNuxtModule {
   (this: ModuleContainer, inlineOptions?: ModuleOptions): void | Promise<void>
   meta?: ModuleMeta
 }
 
+/** A Nuxt module definition */
 export interface NuxtModule<T extends ModuleOptions = any> extends ModuleMeta {
   defaults?: T
   setup?: (this: null, resolvedOptions: T, nuxt: Nuxt) => void | Promise<void>
@@ -38,14 +46,19 @@ export type ModuleInstallOptions =
 // -- Templates --
 
 export interface TemplateOpts {
+  /** The target filename once the template is copied into the Nuxt buildDir */
   filename?: string
+  /** The target filename once the template is copied into the Nuxt buildDir */
   fileName?: string
+  /** An options object that will be accessible within the template via `<% options %>` */
   options?: Record<string, any>
+  /** The resolved path to the source file to be templated */
   src: string
 }
 
 export interface PluginTemplateOpts extends TemplateOpts {
   /** @deprecated use mode */
   ssr?: boolean
+  /** Whether the plugin will be loaded on only server-side, only client-side or on both. */
   mode?: 'all' | 'server' | 'client'
 }
diff --git a/packages/kit/src/types/nuxt.ts b/packages/kit/src/types/nuxt.ts
index f32ec1bfca..3bfb51b245 100644
--- a/packages/kit/src/types/nuxt.ts
+++ b/packages/kit/src/types/nuxt.ts
@@ -2,15 +2,20 @@ import { NuxtHookName, NuxtHooks } from './hooks'
 import { NuxtOptions } from './config'
 
 export interface Nuxt {
+  /** The resolved Nuxt configuration. */
   options: NuxtOptions
 
   hooks: {
+    /** Register a function to be run when the named Nuxt hook is called. */
     hook<Hook extends NuxtHookName>(hookName: Hook, callback: NuxtHooks[Hook]): void | Promise<void>
+    /** Run all Nuxt hooks that have been registered against the hook name. */
     callHook<Hook extends NuxtHookName>(hookName: Hook, ...args: Parameters<NuxtHooks[Hook]>): ReturnType<NuxtHooks[Hook]>
+    /** Add all hooks in the object passed in. */
     addHooks(hooks: Partial<NuxtHooks>): void
   }
   hook: Nuxt['hooks']['hook']
   callHook: Nuxt['hooks']['callHook']
 
+  /** The production or development server */
   server?: any
 }
diff --git a/packages/kit/src/utils/cjs.ts b/packages/kit/src/utils/cjs.ts
index ebfb66c0f6..8eba787c2b 100644
--- a/packages/kit/src/utils/cjs.ts
+++ b/packages/kit/src/utils/cjs.ts
@@ -9,8 +9,11 @@ export interface ResolveModuleOptions {
 }
 
 export interface RequireModuleOptions extends ResolveModuleOptions {
-  native?: boolean
+  // TODO: use create-require for jest environment
+  // native?: boolean
+  /** Clear the require cache (force fresh require) but only if not within `node_modules` */
   clearCache?: boolean
+  /** Automatically de-default the result of requiring the module. */
   interopDefault?: boolean
 }
 
@@ -63,6 +66,7 @@ export function scanRequireTree (id: string, files = new Set<string>()) {
   return files
 }
 
+/** Access the require cache by module id. */
 export function getRequireCacheItem (id: string) {
   try {
     return _require.cache[id]
@@ -70,16 +74,19 @@ export function getRequireCacheItem (id: string) {
   }
 }
 
+/** Resolve the `package.json` file for a given module. */
 export function requireModulePkg (id: string, opts: RequireModuleOptions = {}) {
   return requireModule(join(id, 'package.json'), opts)
 }
 
+/** Resolve the path of a module. */
 export function resolveModule (id: string, opts: ResolveModuleOptions = {}) {
   return _require.resolve(id, {
     paths: opts.paths
   })
 }
 
+/** Try to resolve the path of a module, but don't emit an error if it can't be found. */
 export function tryResolveModule (path: string, opts: ResolveModuleOptions = {}) {
   try {
     return resolveModule(path, opts)
@@ -90,6 +97,7 @@ export function tryResolveModule (path: string, opts: ResolveModuleOptions = {})
   }
 }
 
+/** Require a module and return it. */
 export function requireModule (id: string, opts: RequireModuleOptions = {}) {
   // Resolve id
   const resolvedPath = resolveModule(id, opts)
@@ -110,6 +118,7 @@ export function requireModule (id: string, opts: RequireModuleOptions = {}) {
   return requiredModule
 }
 
+/** Try to require a module, but don't emit an error if the module can't be required. */
 export function tryRequireModule (id: string, opts: RequireModuleOptions = {}) {
   try {
     return requireModule(id, opts)
diff --git a/packages/kit/src/utils/resolve.ts b/packages/kit/src/utils/resolve.ts
index 318386d5f3..c4a70a61fc 100644
--- a/packages/kit/src/utils/resolve.ts
+++ b/packages/kit/src/utils/resolve.ts
@@ -2,13 +2,23 @@ import { existsSync, lstatSync } from 'fs'
 import { resolve, join } from 'upath'
 
 export interface ResolveOptions {
+  /**
+   * The base path against which to resolve the path
+   *
+   * @default .
+   */
   base?: string
+  /**
+   * An object of aliases (alias, path) to take into account, for example
+   * `{ 'example/alias': '/full/path/to/alias' }`
+   */
   alias?: Record<string, string>
+  /** The file extensions to try (for example, ['js', 'ts']) */
   extensions?: string[]
 }
 
 function resolvePath (path: string, opts: ResolveOptions = {}) {
-  // Fast return in case of path exists
+  // Fast return if the path exists
   if (existsSync(path)) {
     return path
   }
@@ -55,6 +65,15 @@ function resolvePath (path: string, opts: ResolveOptions = {}) {
   throw new Error(`Cannot resolve "${path}" from "${resolvedPath}"`)
 }
 
+/**
+ * Return a path with any relevant aliases resolved.
+ *
+ * @example
+ * ```js
+ * const aliases = { 'test': '/here/there' }
+ * resolveAlias('test/everywhere', aliases)
+ * // '/here/there/everywhere'
+ */
 export function resolveAlias (path: string, alias: ResolveOptions['alias']) {
   for (const key in alias) {
     if (path.startsWith(key)) {
@@ -64,6 +83,10 @@ export function resolveAlias (path: string, alias: ResolveOptions['alias']) {
   return path
 }
 
+/**
+ * Resolve the path of a file but don't emit an error,
+ * even if the module can't be resolved.
+ */
 export function tryResolvePath (path: string, opts: ResolveOptions = {}) {
   try {
     return resolvePath(path, opts)
diff --git a/yarn.lock b/yarn.lock
index ac773f4387..9d8b9995da 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -4401,6 +4401,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"comment-parser@npm:1.1.2":
+  version: 1.1.2
+  resolution: "comment-parser@npm:1.1.2"
+  checksum: b61e90aa9e725d352c09697933536256e76e23498a5f8720324b354f4910edd1dbdbb1b1a83b8ed6d98ff37781c973bb0a355e57afe4b092e0e63273f10fc61d
+  languageName: node
+  linkType: hard
+
 "commondir@npm:^1.0.1":
   version: 1.0.1
   resolution: "commondir@npm:1.0.1"
@@ -4977,7 +4984,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"debug@npm:4, debug@npm:^4.0.1, debug@npm:^4.1.0, debug@npm:^4.1.1":
+"debug@npm:4, debug@npm:^4.0.1, debug@npm:^4.1.0, debug@npm:^4.1.1, debug@npm:^4.3.1":
   version: 4.3.2
   resolution: "debug@npm:4.3.2"
   dependencies:
@@ -5682,6 +5689,23 @@ __metadata:
   languageName: node
   linkType: hard
 
+"eslint-plugin-jsdoc@npm:^32.3.0":
+  version: 32.3.0
+  resolution: "eslint-plugin-jsdoc@npm:32.3.0"
+  dependencies:
+    comment-parser: 1.1.2
+    debug: ^4.3.1
+    jsdoctypeparser: ^9.0.0
+    lodash: ^4.17.20
+    regextras: ^0.7.1
+    semver: ^7.3.4
+    spdx-expression-parse: ^3.0.1
+  peerDependencies:
+    eslint: ^6.0.0 || ^7.0.0
+  checksum: f4665eb3c4b32d139342028a9f0d96b095214778a3e32b8a1461d397674954c4d36a0c019f11eefcfa64202c2ad71ecf558e5a553d8a3827b3ccfef2391a741c
+  languageName: node
+  linkType: hard
+
 "eslint-plugin-node@npm:^11.1.0":
   version: 11.1.0
   resolution: "eslint-plugin-node@npm:11.1.0"
@@ -8385,6 +8409,15 @@ __metadata:
   languageName: node
   linkType: hard
 
+"jsdoctypeparser@npm:^9.0.0":
+  version: 9.0.0
+  resolution: "jsdoctypeparser@npm:9.0.0"
+  bin:
+    jsdoctypeparser: bin/jsdoctypeparser
+  checksum: d0c855be23ddb77260d54c8d833bf089e2e5a08f7b7dd7fdd60c35d3a222669e2edadc455fd69c435e593413e09b6792410d1d877c8f423662053f5e5012513b
+  languageName: node
+  linkType: hard
+
 "jsdom@npm:^16.4.0":
   version: 16.5.3
   resolution: "jsdom@npm:16.5.3"
@@ -9985,6 +10018,7 @@ __metadata:
     "@types/jest": ^26.0.22
     "@types/node": ^14.14.37
     eslint: ^7.24.0
+    eslint-plugin-jsdoc: ^32.3.0
     jest: ^26.6.3
     jiti: ^1.9.1
     lerna: ^4.0.0
@@ -11676,6 +11710,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"regextras@npm:^0.7.1":
+  version: 0.7.1
+  resolution: "regextras@npm:0.7.1"
+  checksum: 60e965d826751da5c7c744c9ecdca3bd90026f8376ec6a362b04b9eeb8140e8be5f6028de155f9b4d3a713344aff625668522c3fb3fc391aec67815bdc3ab509
+  languageName: node
+  linkType: hard
+
 "remove-trailing-separator@npm:^1.0.1":
   version: 1.1.0
   resolution: "remove-trailing-separator@npm:1.1.0"
@@ -12553,7 +12594,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"spdx-expression-parse@npm:^3.0.0":
+"spdx-expression-parse@npm:^3.0.0, spdx-expression-parse@npm:^3.0.1":
   version: 3.0.1
   resolution: "spdx-expression-parse@npm:3.0.1"
   dependencies: