Laravel Precognition: Live Validation That Reuses Your Backend Rules

What a precognitive request actually is

A precognitive request is a normal HTTP request to your real endpoint, tagged with a Precognition: true header. Laravel sees the header, runs the route's middleware and validation, and then stops before your controller does any real work. It never writes a row. It never sends an email. It runs the rules and returns the verdict.

Success comes back as 204 No Content with a Precognition-Success: true header. Failure comes back as a normal 422 with the same JSON error bag your form submit would produce. Same rules, same messages, same field names. There is no second schema to drift.

The lifecycle is worth holding in your head:

1. Front end sends the form state to the real URL with Precognition: true.


2. Middleware runs. FormRequest validation runs.


3. Laravel short-circuits: your controller body never executes.


4. Response is 204 (valid) or 422 (invalid).

The controller is skipped by design. That is what makes it safe to fire on every keystroke.

Wiring the backend

You need two things: the middleware on the route, and a form request that already holds your rules. If you have the form request, you are most of the way there.

use App\Http\Requests\StoreUserRequest;

use Illuminate\Foundation\Http\Middleware\HandlePrecognitiveRequests;



Route::post('/users', [UserController::class, 'store'])

    ->middleware(HandlePrecognitiveRequests::class);

The form request is unchanged. This is the same class your real POST already validates against:

<?php



namespace App\Http\Requests;



use Illuminate\Foundation\Http\FormRequest;

use Illuminate\Validation\Rules\Password;



class StoreUserRequest extends FormRequest

{

    public function rules(): array

    {

        return [

            'name'  => ['required', 'string', 'max:120'],

            'email' => ['required', 'email', 'max:255'],

            'password' => [

                'required',

                'confirmed',

                Password::min(12)->mixedCase()->numbers(),

            ],

        ];

    }

}

One ruleset. The submit path uses it. The live-check path uses it. When you raise the password minimum, both paths move together because there is only one place to edit.

The live check on the front end

Laravel ships a small client per framework: , and

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