Inertia

Inertia is a framework-agnostic way to create single-page applications without much of the complexity of modern SPAs.

It is a great middle ground between traditional server-rendered applications (with templating engines) and modern SPAs (with client-side routing and state management).

Using Inertia will allow you to create a SPA with your favorite frontend framework (Vue.js, React, Svelte or Solid.js) without creating a separate API.

import type { HttpContext } from '@adonisjs/core/http'

export default class UsersController {
  public async index({ inertia }: HttpContext) {
    const users = await User.all()

    return inertia.render('users/index', { users })
  }
}

<script setup lang="ts">
import { Link, Head } from '@inertiajs/vue3'

defineProps<{
  users: SerializedUser[]
}>()
</script>

<template>
  <Head title="Users" />

  <div v-for="user in users" :key="user.id">
    <Link :href="`/users/${user.id}`">
      {{ user.name }}
    </Link>
    <div>{{ user.email }}</div>
  </div>
</template>

Installation

Are you starting a new project and want to use Inertia? Check out the Inertia starter kit.

Install the package from the npm registry using one of the following commands.

npm i @adonisjs/inertia

pnpm add @adonisjs/inertia

yarn add @adonisjs/inertia

Once done, run the following command to configure the package.

node ace configure @adonisjs/inertia

Registers the following service provider and command inside the adonisrc.ts file.

{
  providers: [
    // ...other providers
    () => import('@adonisjs/inertia/inertia_provider')
  ]
}

Registers the following middleware inside the start/kernel.ts file
```
router.use([() => import('@adonisjs/inertia/inertia_middleware')])
```
Create the config/inertia.ts file.
Copy a few stubs into your application to help you start quickly. Each copied file is adapted to the frontend framework previously selected.
Create a ./resources/views/inertia_layout.edge file that will be used to render the HTML page used to boot Inertia.
Create a ./inertia/css/app.css file with the content needed to style the root.edge view.
Create a ./inertia/tsconfig.json file to differentiate between the server and client-side TypeScript configuration.
Create a ./inertia/app/app.ts for bootstrapping Inertia and your frontend framework.
Create a ./inertia/pages/home.{tsx|vue|svelte} file to render the home page of your application.
Create a ./inertia/pages/server_error.{tsx|vue|svelte} and ./inertia/pages/not_found.{tsx|vue|svelte} files to render the error pages.
Add the correct vite plugin to compile your frontend framework in the vite.config.ts file.
Add a dumb route /inertia in your start/routes.ts file to render the home page with Inertia
Install packages based on the selected frontend framework.

Once done, you should be ready to use Inertia in your AdonisJS application. Start your development server and visit the /inertia route to see the home page rendered using Inertia and your selected frontend framework.

Read the Inertia official documentation.

Inertia is a backend-agnostic library. We just created an adapter to make it work with AdonisJS. You should be familiar with the Inertia concepts before reading this documentation.

We will only cover AdonisJS's specific parts in this documentation.

Client-side entrypoint

If you used the configure or add command, the package will have created an entrypoint file at inertia/app/app.ts so you can skip this step.

Basically, this file will be the main entrypoint for your frontend application and will be used to bootstrap Inertia and your frontend framework. This file should be the entrypoint loaded by your root Edge template with the @vite tag.

import { createApp, h } from 'vue'
import type { DefineComponent } from 'vue'
import { createInertiaApp } from '@inertiajs/vue3'
import { resolvePageComponent } from '@adonisjs/inertia/helpers'

const appName = import.meta.env.VITE_APP_NAME || 'AdonisJS'

createInertiaApp({
  title: (title) => {{ `${title} - ${appName}` }},
  resolve: (name) => {
    return resolvePageComponent(
      `./pages/${name}.vue`,
      import.meta.glob<DefineComponent>('./pages/**/*.vue'),
    )
  },
  setup({ el, App, props, plugin }) {
    createApp({ render: () => h(App, props) })
      .use(plugin)
      .mount(el)
  },
})

import { createRoot } from 'react-dom/client';
import { createInertiaApp } from '@inertiajs/react';
import { resolvePageComponent } from '@adonisjs/inertia/helpers'

const appName = import.meta.env.VITE_APP_NAME || 'AdonisJS'

createInertiaApp({
  progress: { color: '#5468FF' },

  title: (title) => `${title} - ${appName}`,

  resolve: (name) => {
    return resolvePageComponent(
      `./pages/${name}.tsx`,
      import.meta.glob('./pages/**/*.tsx'),
    )
  },

  setup({ el, App, props }) {
    const root = createRoot(el);
    root.render(<App {...props} />);
  },
});

import { createInertiaApp } from '@inertiajs/svelte'
import { resolvePageComponent } from '@adonisjs/inertia/helpers'

const appName = import.meta.env.VITE_APP_NAME || 'AdonisJS'

createInertiaApp({
  progress: { color: '#5468FF' },

  title: (title) => `${title} - ${appName}`,

  resolve: (name) => {
    return resolvePageComponent(
      `./pages/${name}.svelte`,
      import.meta.glob('./pages/**/*.svelte'),
    )
  },

  setup({ el, App, props }) {
    new App({ target: el, props })
  },
})

import { render } from 'solid-js/web'
import { createInertiaApp } from 'inertia-adapter-solid'
import { resolvePageComponent } from '@adonisjs/inertia/helpers'

const appName = import.meta.env.VITE_APP_NAME || 'AdonisJS'

createInertiaApp({
  progress: { color: '#5468FF' },

  title: (title) => `${title} - ${appName}`,

  resolve: (name) => {
    return resolvePageComponent(
      `./pages/${name}.tsx`,
      import.meta.glob('./pages/**/*.tsx'),
    )
  },

  setup({ el, App, props }) {
    render(() => <App {...props} />, el)
  },
})

The role of this file is to create an Inertia app and to resolve the page component. The page component you write when using inertia.render will be passed down the the resolve function and the role of this function is to return the component that need to be rendered.

Rendering pages

While configuring your package, a inertia_middleware has been registered inside the start/kernel.ts file. This middleware is responsible for setting up the inertia object on the HttpContext.

To render a view using Inertia, use the inertia.render method. The method accepts the view name and the data to be passed to the component as props.

app/controllers/home_controller.ts

export default class HomeController {
  public async index({ inertia }: HttpContext) {
    return inertia.render('home', { user: { name: 'julien' } })
  }
}

Do you see the home passed to the inertia.render method? It should be the path to the component file relative to the inertia/pages directory. We render the inertia/pages/home.(vue,tsx) file here.

Your frontend component will receive the user object as a prop :

<script setup lang="ts">
defineProps<{
  user: { name: string }
}>()
</script>

<template>
  <p>Hello {{ user.name }}</p>
</template>

export default function Home(props: { user: { name: string } }) {
  return <p>Hello {props.user.name}</p>
}

<script lang="ts">
export let user: { name: string }
</script>

<Layout>
  <p>Hello {user.name}</p>
</Layout>

export default function Home(props: { user: { name: string } }) {
  return <p>Hello {props.user.name}</p>
}

As simple as that.

While passing data to the frontend, everything is serialized to JSON. Do not expect to pass instances of models, dates, or other complex objects.

Root Edge template

The Root template is a regular Edge template that will be loaded on the first-page visit of your application. It is the place where you should include your CSS and Javascript files and also where you should include the @inertia tag. A typical root template looks like this :

<!DOCTYPE html>
<html>

<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title inertia>AdonisJS x Inertia</title>

  @inertiaHead()
  @vite(['inertia/app/app.ts', `inertia/pages/${page.component}.vue`])
</head>

<body>
  @inertia()
</body>

</html>

<!DOCTYPE html>
<html>

<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title inertia>AdonisJS x Inertia</title>

  @inertiaHead()
  @viteReactRefresh()
  @vite(['inertia/app/app.tsx', `inertia/pages/${page.component}.tsx`])
</head>

<body>
  @inertia()
</body>

</html>

<!DOCTYPE html>
<html>

<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title inertia>AdonisJS x Inertia</title>

  @inertiaHead()
  @vite(['inertia/app/app.ts', `inertia/pages/${page.component}.svelte`])
</head>

<body>
  @inertia()
</body>

</html>

<!DOCTYPE html>
<html>

<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title inertia>AdonisJS x Inertia</title>

  @inertiaHead()
  @vite(['inertia/app/app.tsx', `inertia/pages/${page.component}.tsx`])
</head>

<body>
  @inertia()
</body>

</html>

You can configure the root template path in the config/inertia.ts file. By default, it assumes your template is at resources/views/root.edge.

import { defineConfig } from '@adonisjs/inertia'

export default defineConfig({
  // The path to the root template relative 
  // to the `resources/views` directory
  rootView: 'app_root', 
})

Root template data

You may want to share data with your root Edge template. For example, for adding a meta title or open graph tags. You can do so by using the 3rd argument of the inertia.render method :

app/controllers/posts_controller.ts

export default class PostsController {
  public async index({ inertia }: HttpContext) {
    return inertia.render('posts/details', post, {
      title: post.title,
      description: post.description
    })
  }
}

The title and description will now be available to the root Edge template :

resources/views/root.edge

<html>
  <title>{{ title }}</title>
  <meta name="description" content="{{ description }}">

  <body>
    @inertia()
  </body>
</html

Redirects

It is how you should do it in AdonisJS :

export default class UsersController {
  async store({ inertia, response }: HttpContext) {
    await User.create(request.body())

    // 👇 You can use standard AdonisJS redirections
    return response.redirect().toRoute('users.index')
  }

  async externalRedirect({ response }: HttpContext) {
    // 👇 Or use the inertia.location for external redirects
    return inertia.location('https://adonisjs.com')
  }
}

See the official documentation for more information.

Sometimes, you may need to share the same data across multiple views. For instance, we are sharing the current user information with all views. Having to do this for every controller can become tedious. Fortunately, we have two solutions for this issue.

`sharedData`

In the config/inertia.ts file, you can define a sharedData object. This object allows you to define data that should be shared with all views.

import { defineConfig } from '@adonisjs/inertia'

export default defineConfig({
  sharedData: {
    // 👇 This will be available in all views
    appName: 'My App' ,
    // 👇 Scoped to the current request
    user: (ctx) => ctx.auth?.user, 
    // 👇 Scoped to the current request
    errors: (ctx) => ctx.session.flashMessages.get('errors'),
  },
})

Sometimes, sharing data from a middleware rather than the config/inertia.ts file might be more convenient. You can do so by using the inertia.share method :

import type { HttpContext } from '@adonisjs/core/http'
import type { NextFn } from '@adonisjs/core/types/http'

export default class MyMiddleware {
  public async handle({ inertia }: HttpContext, next: NextFn) {
    inertia.share('appName', 'My App')
    inertia.share('user', (ctx) => ctx.auth?.user)
  }
}

Partial reloads & Lazy data evaluation

First read the official documentation to understand what partial reloads are and how they work.

About lazy data evaluation, here is how it works in AdonisJS :

export default class UsersController {
  public async index({ inertia }: HttpContext) {
    return inertia.render('users/index', {
      // ALWAYS included on first visit.
      // OPTIONALLY included on partial reloads.
      // ALWAYS evaluated
      users: await User.all(),

      // ALWAYS included on first visit.
      // OPTIONALLY included on partial reloads.
      // ONLY evaluated when needed
      users: () => User.all(),

      // NEVER included on first visit.
      // OPTIONALLY included on partial reloads.
      // ONLY evaluated when needed
      users: inertia.lazy(() => User.all())
    }),
  }
}

Usually, you will want to share the types of the data you are passing to your frontend pages components. A simple way to do this is to use the InferPageProps type.

export class UsersController {
  index() {
    return inertia.render('users/index', {
      users: [
        { id: 1, name: 'julien' }
        { id: 2, name: 'virk' },
        { id: 3, name: 'romain' },
      ]
    })
  }
}

import { InferPageProps } from '@adonisjs/inertia/types'
import type { UsersController } from '../../controllers/users_controller.ts'

export function UsersPage(
  // 👇 It will be correctly typed based
  // on what you passed to inertia.render
  // in your controller
  props: InferPageProps<UsersController, 'index'>
) {
  return (
    // ...
  )
}

You will also need to ensure that your frontend is aware of the types you're passing. To do this, you need to add this line to your inertia/app/app.ts file:

/// <reference path="../../adonisrc.ts" />

Note that the InferPageProps will "serialize at type-level" the data you are passing. For example, if you pass a Date object to inertia.render, the resulting type of InferPageProps will be string.

If you're using Vue, you'll have to manually define each property in your defineProps. This is an annoying limitation of Vue, see https://github.com/vitejs/vite-plugin-vue/issues/167.

<script setup lang="ts">
import { InferPageProps } from '@adonisjs/inertia'

defineProps<{
  // 👇 You will have to manually define each prop
  users: InferPageProps<UsersController, 'index'>['users'],
  posts: InferPageProps<PostsController, 'index'>['posts'],
}>()

</script>

CSRF

If you enabled CSRF protection for your application, enable the enableXsrfCookie option in the config/shield.ts file.

Enabling this option will ensure that the XSRF-TOKEN cookie is set on the client side and sent back to the server with every request.

No additional configuration is needed to make Inertia work with CSRF protection.

Asset versioning

When re-deploying your application, your users should always get the latest version of your client-side assets. It is something supported out-of-the-box by the Inertia protocol and AdonisJS.

By default, the @adonisjs/inertia package will compute a hash for the public/assets/manifest.json file and use it as the version of your assets.

If you want to tweak this behavior, you can edit the config/inertia.ts file. The version prop defines the version of your assets and can be a string or a function.

import { defineConfig } from '@adonisjs/inertia'

export default defineConfig({
  version: 'v1'
})

Read the official documentation for more information.

SSR

Enabling SSR

Inertia Starter Kit comes with server-side rendering (SSR) support out of the box. So make sure to use it if you want to enable SSR for your application.

If you started your application without enabling SSR, you can always enable it later by following the following steps :

Adding a server entrypoint

We need to add a server entrypoint that looks super similar to the client entrypoint. This entrypoint will render the first-page visit on the server and not on the browser.

You must create a inertia/app/ssr.ts that default export a function like this :

import { createInertiaApp } from '@inertiajs/vue3'
import { renderToString } from '@vue/server-renderer'
import { createSSRApp, h, type DefineComponent } from 'vue'

export default function render(page) {
  return createInertiaApp({
    page,
    render: renderToString,
    resolve: (name) => {
      const pages = import.meta.glob<DefineComponent>('./pages/**/*.vue')
      return pages[`./pages/${name}.vue`]()
    },

    setup({ App, props, plugin }) {
      return createSSRApp({ render: () => h(App, props) }).use(plugin)
    },
  })
}

import ReactDOMServer from 'react-dom/server'
import { createInertiaApp } from '@inertiajs/react'

export default function render(page) {
  return createInertiaApp({
    page,
    render: ReactDOMServer.renderToString,
    resolve: (name) => {
      const pages = import.meta.glob('./pages/**/*.tsx', { eager: true })
      return pages[`./pages/${name}.tsx`]
    },
    setup: ({ App, props }) => <App {...props} />,
  })
}

import { createInertiaApp } from '@inertiajs/svelte'
import createServer from '@inertiajs/svelte/server'

export default function render(page) {
  return createInertiaApp({
    page,
    resolve: name => {
      const pages = import.meta.glob('./pages/**/*.svelte', { eager: true })
      return pages[`./pages/${name}.svelte`]
    },
  })
}

import { hydrate } from 'solid-js/web'
import { createInertiaApp } from 'inertia-adapter-solid'

export default function render(page: any) {
  return createInertiaApp({
    page,
    resolve: (name) => {
      const pages = import.meta.glob('./pages/**/*.tsx', { eager: true })
      return pages[`./pages/${name}.tsx`]
    },
    setup({ el, App, props }) {
      hydrate(() => <App {...props} />, el)
    },
  })
}

Update the config file

Head over to the config/inertia.ts file and update the ssr prop to enable it. Also, point to your server entrypoint if you use a different path.

import { defineConfig } from '@adonisjs/inertia'

export default defineConfig({
  // ...
  ssr: {
    enabled: true,
    entrypoint: 'inertia/app/ssr.tsx'
  }
})

Update the Vite config

First, make sure you have registered the inertia vite plugin. Once done, you should update the path to the server entrypoint in the vite.config.ts file if you use a different path.

import { defineConfig } from 'vite'
import inertia from '@adonisjs/inertia/client'

export default defineConfig({
  plugins: [
    inertia({
      ssr: {
        enabled: true,
        entrypoint: 'inertia/app/ssr.tsx'
      }
    })
  ]
})

You should now be able to render the first-page visit on the server and then continue with the client-side rendering.

SSR Allowlist

When using SSR, you may want to not server-side render all your components. For example, you are building an admin dashboard gated by authentication, so these routes have no reason to be rendered on the server. But on the same application, you may have a landing page that could benefit from SSR to improve SEO.

So, you can add the pages that should be rendered on the server in the config/inertia.ts file.

import { defineConfig } from '@adonisjs/inertia'

export default defineConfig({
  ssr: {
    enabled: true,
    pages: ['home']
  }
})

You can also pass a function to the pages prop to dynamically decide which pages should be rendered on the server.

import { defineConfig } from '@adonisjs/inertia'

export default defineConfig({
  ssr: {
    enabled: true,
    pages: (ctx, page) => page.startsWith('admin')
  }
})

Testing

There are several ways to test your frontend code:

End-to-end testing. You can use the Browser Client, a seamless integration between Japa and Playwright.
Unit testing. We recommend using testing tools adapted for the frontend ecosystem, particularly Vitest.

And finally, you can also test your Inertia endpoints to ensure they return the correct data. For that, we have a few test helpers available in Japa.

First, make sure to configure the inertiaApiClient and apiClient plugins in your test/bootsrap.ts file if you haven't already done so:

tests/bootstrap.ts

import { assert } from '@japa/assert'
import app from '@adonisjs/core/services/app'
import { pluginAdonisJS } from '@japa/plugin-adonisjs'
import { apiClient } from '@japa/api-client'
import { inertiaApiClient } from '@adonisjs/inertia/plugins/api_client'

export const plugins: Config['plugins'] = [
  assert(), 
  pluginAdonisJS(app),
  apiClient(),
  inertiaApiClient(app)
]

Next, we can request our Inertia endpoint using withInertia() to ensure the data is correctly returned in JSON format.

test('returns correct data', async ({ client }) => {
  const response = await client.withInertia().get('/home')

  response.assertStatus(200)
  response.assertInertiaComponent('home/main')
  response.assertInertiaProps({ user: { name: 'julien' } })
})

Let's take a look at the various assertions available to test your endpoints:

`withInertia()`

Adds the X-Inertia header to the request. It ensures that data is correctly returned in JSON format.

`assertInertiaComponent()`

Checks that the component returned by the server is the one expected.

test('returns correct data', async ({ client }) => {
  const response = await client.withInertia().get('/home')

  response.assertInertiaComponent('home/main')
})

`assertInertiaProps()`

Checks that the props returned by the server are exactly those passed as parameters.

test('returns correct data', async ({ client }) => {
  const response = await client.withInertia().get('/home')

  response.assertInertiaProps({ user: { name: 'julien' } })
})

`assertInertiaPropsContains()`

Checks that the props returned by the server contain some of the props passed as parameters. It uses containsSubset under the hood.

test('returns correct data', async ({ client }) => {
  const response = await client.withInertia().get('/home')

  response.assertInertiaPropsContains({ user: { name: 'julien' } })
})

Additional properties

In addition to this, you can access the following properties on ApiResponse :

test('returns correct data', async ({ client }) => {
  const { body } = await client.withInertia().get('/home')

  // 👇 The component returned by the server
  console.log(response.inertiaComponent) 

  // 👇 The props returned by the server
  console.log(response.inertiaProps)
})

FAQ

Why my server is constantly reloading when updating my frontend code?

Let's say you are using React. Every time you update your frontend code, the server will reload and the browser will refresh. You are not benefiting from the hot module replacement (HMR) feature.

You need to exclude inertia/**/* from your root tsconfig.json file to make it work.

{
  "compilerOptions": {
    // ...
  },
  "exclude": ["inertia/**/*"]
}

Because, the AdonisJS process that is responsible for restarting the server is watching files included in the tsconfig.json file.

Why my production build is not working ?

A common issue is that you just forgot to set NODE_ENV=production when running your production build.