feat(docs): useNuxt and tryUseNuxt hooks

docs/3.api/4.advanced/2.kit.md

@@ -989,7 +989,124 @@ An object with the following properties:
 
 [source code](https://github.com/nuxt/nuxt/blob/main/packages/kit/src/context.ts)
 
-- `useNuxt()`
+::alert{type=info}
+Keep in mind, Nuxt already pass itself as the second argument to the `setup` function, so you can use it instead of `useNuxt()` call. `useNuxt()` and `tryUseNuxt()` calls are useful when you want to access Nuxt in separate functions. You can look at [Nuxt Site Config](https://github.com/harlan-zw/nuxt-site-config) as a reference.
+::
+
+### `useNuxt()`
+
+Get the Nuxt instance from the context. It will throw an error if Nuxt is not available.
+
+#### Type
+
+```ts
+function useNuxt(): Nuxt
+
+interface Nuxt {
+  options: NuxtOptions
+  hooks: Hookable<NuxtHooks>
+  hook: Nuxt['hooks']['hook']
+  callHook: Nuxt['hooks']['callHook']
+  addHooks: Nuxt['hooks']['addHooks']
+  ready: () => Promise<void>
+  close: () => Promise<void>
+  server?: any
+  vfs: Record<string, string>
+  apps: Record<string, NuxtApp>
+}
+```
+
+#### Examples
+
+::code-group
+
+```ts [setupTranspilation.ts]
+// https://github.com/Lexpeartha/nuxt-xstate/blob/main/src/parts/transpile.ts
+import { useNuxt } from '@nuxt/kit'
+
+export const setupTranspilation = () => {
+  const nuxt = useNuxt()
+
+  nuxt.options.build.transpile = nuxt.options.build.transpile || []
+
+  if (nuxt.options.builder === '@nuxt/webpack-builder') {
+    nuxt.options.build.transpile.push(
+      'xstate',
+    )
+  }
+}
+```
+
+```ts [module.ts]
+import { useNuxt } from '@nuxt/kit'
+import { setupTranspilation } from './setupTranspilation'
+
+export default defineNuxtModule({
+  setup() {
+    setupTranspilation()
+  }
+})
+```
+
+::
+
+## `tryUseNuxt()`
+
+Get the Nuxt instance from the context. It will return `null` if Nuxt is not available.
+
+#### Type
+
+```ts
+function tryUseNuxt(): Nuxt | null
+
+interface Nuxt {
+  options: NuxtOptions
+  hooks: Hookable<NuxtHooks>
+  hook: Nuxt['hooks']['hook']
+  callHook: Nuxt['hooks']['callHook']
+  addHooks: Nuxt['hooks']['addHooks']
+  ready: () => Promise<void>
+  close: () => Promise<void>
+  server?: any
+  vfs: Record<string, string>
+  apps: Record<string, NuxtApp>
+}
+```
+
+#### Examples
+
+::code-group
+
+```ts [requireSiteConfig.ts]
+// https://github.com/harlan-zw/nuxt-site-config/blob/main/test/assertions.test.ts
+import { tryUseNuxt } from '@nuxt/kit'
+
+interface SiteConfig {
+  title: string
+}
+
+export const requireSiteConfig = (): SiteConfig => {
+  const nuxt = tryUseNuxt()
+  if (!nuxt) {
+    return { title: null }
+  }
+  return nuxt.options.siteConfig
+}
+```
+
+```ts [module.ts]
+import { useNuxt } from '@nuxt/kit'
+import { requireSiteConfig } from './requireSiteConfig'
+
+export default defineNuxtModule({
+  setup(_, nuxt) {
+    const config = requireSiteConfig()
+    nuxt.options.app.head.title = config.title
+  }
+})
+```
+
+::
 
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