What is Precognition
Precognition is a mechanism that runs server-side validation before a form is submitted.
You can use your Laravel rules as-is on the frontend without redefining them.
Unlike normal requests, Precognition requests execute a route’s middleware and form request validation, but not the controller method body itself.
That makes it well-suited to real-time validation as the user types.
Installation
In Laravel 13, you don’t need to install the backend laravel/precognition package.
What you do need is a frontend helper package.
- Vue:
laravel-precognition-vue
- React:
laravel-precognition-react
- Alpine.js:
laravel-precognition-alpine
npm install laravel-precognition-vue
npm install laravel-precognition-react
npm install laravel-precognition-alpine
Inertia has built-in Precognition support from 2.3, and it also works out of the box in Inertia 3.
When using Inertia forms, you typically don’t need to add laravel-precognition-vue / laravel-precognition-react.
Backend configuration
Add the HandlePrecognitiveRequests middleware to your route.
It’s practical to gather validation rules into a form request.
Consolidating rules into a form request makes reuse and separation of concerns easier.
use App\Http\Requests\StoreUserRequest;
use Illuminate\Foundation\Http\Middleware\HandlePrecognitiveRequests;
use Illuminate\Support\Facades\Route;
Route::post('/users', function (StoreUserRequest $request) {
// Only executed on a real submission
})->middleware([HandlePrecognitiveRequests::class]);
If you have custom middleware with side effects, skip them during Precognition.
public function handle(Request $request, Closure $next): mixed
{
if (! $request->isPrecognitive()) {
Interaction::incrementFor($request->user());
}
return $next($request);
}
Frontend integration
Alpine.js (Blade)
<form x-data="{
form: $form('post', '/users', { name: '', email: '' }),
}">
@csrf
<input x-model="form.name" @change="form.validate('name')" />
<template x-if="form.invalid('name')">
<div x-text="form.errors.name"></div>
</template>
</form>
Vue (Inertia.js)
<script setup>
import { useForm } from 'laravel-precognition-vue';
const form = useForm('post', '/users', {
name: '',
email: '',
});
</script>
<template>
<input v-model="form.name" @change="form.validate('name')" />
<div v-if="form.invalid('name')">{{ form.errors.name }}</div>
</template>
React (Inertia.js)
import { useForm } from 'laravel-precognition-react';
const form = useForm('post', '/users', {
name: '',
email: '',
});
<input
value={form.data.name}
onChange={(e) => form.setData('name', e.target.value)}
onBlur={() => form.validate('name')}
/>
Vanilla JS with Axios
The Precognition library uses Axios.
To use your existing Axios instance, swap it in with client.use().
import Axios from 'axios';
import { client } from 'laravel-precognition-vue';
window.axios = Axios.create();
window.axios.defaults.headers.common['Authorization'] = authToken;
client.use(window.axios);
Controlling validation timing
Use validate() to validate individual inputs.
You can adjust the debounce time with setValidationTimeout().
form.setValidationTimeout(3000);
If you want to validate files every time, use validateFiles().
You can validate array inputs using wildcards.
form.validate('users.*.email');
useForm() handles submission and error state together.
validating: A validation request is in progress
processing: A submission is in progress
errors: A list of errors
valid('field') / invalid('field'): The field’s validation state
submit(): Perform a regular submission
const submit = () => form.submit()
.then(() => form.reset());
Comparing regular requests and Precognition requests
The diagram below shows the difference between how regular and Precognition requests are handled.