Provider validation added.

src/FineTunerServiceProvider.php

@@ -3,6 +3,7 @@
 namespace HalilCosdu\FineTuner;
 
 use HalilCosdu\FineTuner\Commands\FineTunerCommand;
+use InvalidArgumentException;
 use OpenAI;
 use Spatie\LaravelPackageTools\Package;
 use Spatie\LaravelPackageTools\PackageServiceProvider;
@@ -25,11 +26,21 @@ public function configurePackage(Package $package): void
     public function packageRegistered(): void
     {
         $this->app->singleton(FineTuner::class, function ($app) {
+            $apiKey = config('finetuner.api_key');
+            $organization = config('finetuner.organization');
+            $timeout = config('finetuner.request_timeout', 30);
+
+            if (! is_string($apiKey) || ($organization !== null && ! is_string($organization))) {
+                throw new InvalidArgumentException(
+                    'The OpenAI API Key is missing. Please publish the [finetuner.php] configuration file and set the [api_key].'
+                );
+            }
+
             return new FineTuner(
                 OpenAI::factory()
-                    ->withApiKey(config('finetuner.api_key'))
-                    ->withOrganization(config('finetuner.organization'))
-                    ->withHttpClient(new \GuzzleHttp\Client(['timeout' => config('finetuner.request_timeout', 600)]))
+                    ->withApiKey($apiKey)
+                    ->withOrganization($organization)
+                    ->withHttpClient(new \GuzzleHttp\Client(['timeout' => $timeout]))
                     ->make()
             );
         });