diff --git a/tests/Unit/SisterCatastoServiceTest.php b/tests/Unit/SisterCatastoServiceTest.php
new file mode 100644
index 0000000..25c1611
--- /dev/null
+++ b/tests/Unit/SisterCatastoServiceTest.php
@@ -0,0 +1,180 @@
+<?php
+
+namespace Tests\Unit;
+
+use Tests\TestCase;
+use App\Models\Amministratore;
+use App\Models\FeCassettoServiceConfig;
+use App\Models\Stabile;
+use App\Services\SisterCatastoService;
+use Illuminate\Support\Facades\Http;
+use Illuminate\Support\Facades\Storage;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use ZipArchive;
+
+class SisterCatastoServiceTest extends TestCase
+{
+    use RefreshDatabase;
+
+    protected function setUp(): void
+    {
+        parent::setUp();
+        Storage::fake('public');
+    }
+
+    public function test_it_resolves_inherited_credentials_successfully()
+    {
+        // Pulisce eventuali config preesistenti
+        FeCassettoServiceConfig::query()->truncate();
+
+        // Crea la configurazione globale
+        FeCassettoServiceConfig::query()->create([
+            'password_script' => 'fallback_script',
+            'base_url' => 'https://thenetworksolution.it/FattureCorrispettivi/ScaricaFatture/CassettoFiscale.php',
+            'username' => 'fallback_user',
+            'password' => 'fallback_pass',
+            'pin' => '12345',
+        ]);
+
+        $service = new SisterCatastoService();
+        $reflector = new \ReflectionClass(SisterCatastoService::class);
+        $method = $reflector->getMethod('resolveCredentials');
+        $method->setAccessible(true);
+
+        $creds = $method->invoke($service, 1);
+
+        $this->assertEquals('fallback_script', $creds['passwordScript']);
+        $this->assertEquals('https://thenetworksolution.it/FattureCorrispettivi/ScaricaFatture/CassettoFiscale.php', $creds['base_url']);
+        $this->assertNotEmpty($creds['app_url']);
+    }
+
+    public function test_it_resolves_credentials_fallback_to_admin_id_4()
+    {
+        FeCassettoServiceConfig::query()->truncate();
+        Amministratore::query()->where('id', 4)->delete();
+
+        // Crea amministratore ID 4
+        $admin = Amministratore::factory()->create([
+            'id' => 4,
+            'fe_cassetto_password_script' => 'admin_4_script_key',
+        ]);
+
+        $service = new SisterCatastoService();
+        $reflector = new \ReflectionClass(SisterCatastoService::class);
+        $method = $reflector->getMethod('resolveCredentials');
+        $method->setAccessible(true);
+
+        $creds = $method->invoke($service, 1);
+
+        $this->assertEquals('admin_4_script_key', $creds['passwordScript']);
+    }
+
+    public function test_it_calculates_correct_isolated_storage_paths()
+    {
+        $admin = Amministratore::factory()->create([
+            'codice_amministratore' => 'HWFGITXK',
+        ]);
+
+        $stabile = Stabile::factory()->create([
+            'codice_stabile' => '0021',
+            'denominazione' => 'Milizie 3',
+            'amministratore_id' => $admin->id,
+        ]);
+
+        $service = new SisterCatastoService();
+        $path = $service->getStoragePath($stabile->id);
+
+        $this->assertEquals('AMMINISTRATORE_HWFGITXK/STABILE_0021_Milizie_3/catasto', $path);
+    }
+
+    public function test_it_skips_api_call_when_cache_is_valid()
+    {
+        $admin = Amministratore::factory()->create([
+            'codice_amministratore' => 'HWFGITXK',
+        ]);
+
+        $stabile = Stabile::factory()->create([
+            'codice_stabile' => '0021',
+            'amministratore_id' => $admin->id,
+        ]);
+
+        $service = new SisterCatastoService();
+        $dirPath = $service->getStoragePath($stabile->id);
+        $localFilename = "visura_F_12_34_sub5.pdf";
+
+        Storage::disk('public')->put("{$dirPath}/{$localFilename}", "Fake PDF Content");
+
+        // Effettua la richiesta con cache=24. Dovrebbe ritornare cached = true senza chiamare HTTP
+        $res = $service->acquistaEPrelevaVisura(
+            $stabile->id,
+            'F',
+            'ROMA Territorio-RM',
+            'H501#ROMA#0#0',
+            '12',
+            '34',
+            '5',
+            null,
+            null,
+            'PDF',
+            'completa',
+            24
+        );
+
+        $this->assertTrue($res['cached']);
+        $this->assertEquals("{$dirPath}/{$localFilename}", $res['file_path']);
+    }
+
+    public function test_it_extracts_zip_archives_for_omoimmobili()
+    {
+        Http::fake([
+            '*/mashVisuraI.php' => Http::response([
+                'url' => 'https://thenetworksolution.it/sister/acquistate/multiple_visure.zip'
+            ], 200),
+            '*/acquistate/multiple_visure.zip' => Http::response($this->generateFakeZipContent(), 200)
+        ]);
+
+        $admin = Amministratore::factory()->create([
+            'codice_amministratore' => 'HWFGITXK',
+        ]);
+
+        $stabile = Stabile::factory()->create([
+            'codice_stabile' => '0021',
+            'amministratore_id' => $admin->id,
+        ]);
+
+        $service = new SisterCatastoService();
+        $dirPath = $service->getStoragePath($stabile->id);
+        $res = $service->acquistaEPrelevaVisura(
+            $stabile->id,
+            'F',
+            'ROMA Territorio-RM',
+            'H501#ROMA#0#0',
+            '12',
+            '34',
+            '5',
+            null,
+            null,
+            'PDF',
+            'completa',
+            0 // Disabilita cache per forzare chiamata http fake
+        );
+
+        $this->assertTrue($res['zip_extracted']);
+        $this->assertTrue(Storage::disk('public')->exists("{$dirPath}/visura1.pdf"));
+        $this->assertTrue(Storage::disk('public')->exists("{$dirPath}/visura2.pdf"));
+    }
+
+    protected function generateFakeZipContent(): string
+    {
+        $tempZipPath = tempnam(sys_get_temp_dir(), 'test_zip_');
+        $zip = new ZipArchive();
+        if ($zip->open($tempZipPath, ZipArchive::CREATE) === true) {
+            $zip->addFromString('visura1.pdf', 'Content of visura 1');
+            $zip->addFromString('visura2.pdf', 'Content of visura 2');
+            $zip->close();
+        }
+        $content = file_get_contents($tempZipPath);
+        unlink($tempZipPath);
+        return $content;
+    }
+}