Define LLM JSON Schemas in Laravel With Forerunner

Last updated on October 29th, 2025 by Paul Redmond

Forerunner for Laravel is a package that provides a migration-inspired API for defining JSON schemas that ensure your LLM responses are perfectly structured every time. Define structured output schemas for LLMs using Laravel's familiar migration syntax:

use Blaspsoft\Forerunner\Schema\Struct;
use Blaspsoft\Forerunner\Schema\Property;
 
$schema = Struct::define('User', 'A user schema', function (Property $property) {
    $property->string('name', 'The user\'s full name')->required();
    $property->string('email', 'The user\'s email address')->required();
    $property->int('age', 'The user\'s age')->min(0)->max(150);
    $property->boolean('is_active', 'Is the user account active?')->default(true);
})->toArray();

The above struct returns an array, and can also be converted to JSON:

{
  "type": "object",
  "properties": {
    "name": {
      "type": "string",
      "description": "The user's full name"
    },
    "email": {
      "type": "string",
      "description": "The user's email address"
    },
    "age": {
      "type": "integer",
      "description": "The user's age",
      "minimum": 0,
      "maximum": 150
    },
    "is_active": {
      "type": "boolean",
      "description": "Is the user account active?",
      "default": true
    }
  },
  "description": "A user schema",
  "required": [
    "name",
    "email"
  ],
  "additionalProperties": false
}