diff --git a/functional_test.php b/functional_test.php
new file mode 100644
index 0000000..6f38f79
--- /dev/null
+++ b/functional_test.php
@@ -0,0 +1,307 @@
+#!/usr/bin/env php
+<?php
+declare(strict_types=1);
+
+require_once __DIR__ . '/includes/config.php';
+
+$options = array_slice($argv, 1);
+if (in_array('--fresh', $options, true) && file_exists(DB_PATH)) {
+    unlink(DB_PATH);
+    echo "Bestehende Datenbank entfernt – wird neu initialisiert.\n";
+}
+
+require_once __DIR__ . '/includes/functions.php';
+require_once __DIR__ . '/includes/auth.php';
+require_once __DIR__ . '/includes/email.php';
+
+if (!isset($_SERVER['REQUEST_METHOD'])) {
+    $_SERVER['REQUEST_METHOD'] = 'GET';
+}
+
+final class FunctionalTestRunner
+{
+    private PDO $pdo;
+    private array $results = [];
+    private int $passed = 0;
+    private int $failed = 0;
+
+    public function __construct(PDO $pdo)
+    {
+        $this->pdo = $pdo;
+    }
+
+    public function run(string $title, callable $test, bool $transactional = false): void
+    {
+        try {
+            if ($transactional) {
+                $this->pdo->beginTransaction();
+            }
+            $details = $test($this->pdo);
+            if ($transactional && $this->pdo->inTransaction()) {
+                $this->pdo->rollBack();
+            }
+            $this->record('PASS', $title, $details);
+        } catch (Throwable $e) {
+            if ($transactional && $this->pdo->inTransaction()) {
+                $this->pdo->rollBack();
+            }
+            $this->record('FAIL', $title, $e->getMessage());
+        }
+    }
+
+    private function record(string $status, string $title, ?string $details): void
+    {
+        $status === 'PASS' ? $this->passed++ : $this->failed++;
+        $this->results[] = [
+            'status' => $status,
+            'title' => $title,
+            'details' => $details ?? '',
+        ];
+    }
+
+    public function summary(): void
+    {
+        foreach ($this->results as $result) {
+            $symbol = $result['status'] === 'PASS' ? '\u{2705}' : '\u{274C}';
+            echo sprintf("%s %s\n", $symbol, $result['title']);
+            if ($result['details'] !== '') {
+                echo sprintf("    %s\n", $result['details']);
+            }
+        }
+        echo str_repeat('-', 50) . "\n";
+        echo sprintf("Ergebnis: %d bestanden, %d fehlgeschlagen\n", $this->passed, $this->failed);
+        exit($this->failed === 0 ? 0 : 1);
+    }
+}
+
+function renderPage(string $file, array $get = [], array $post = []): string
+{
+    $previousGet = $_GET ?? [];
+    $previousPost = $_POST ?? [];
+    $previousMethod = $_SERVER['REQUEST_METHOD'] ?? 'GET';
+
+    $_GET = $get;
+    $_POST = $post;
+    $_SERVER['REQUEST_METHOD'] = empty($post) ? 'GET' : 'POST';
+
+    ob_start();
+    include __DIR__ . '/' . ltrim($file, '/');
+    $output = ob_get_clean();
+
+    $_GET = $previousGet;
+    $_POST = $previousPost;
+    $_SERVER['REQUEST_METHOD'] = $previousMethod;
+
+    return $output;
+}
+
+function restartSession(): void
+{
+    if (session_status() === PHP_SESSION_NONE) {
+        session_start();
+    }
+}
+
+$pdo = db();
+$runner = new FunctionalTestRunner($pdo);
+
+$runner->run('Storage-Verzeichnis vorhanden', function () {
+    if (!is_dir(__DIR__ . '/storage')) {
+        throw new RuntimeException('Ordner storage fehlt.');
+    }
+    return 'Pfad: ' . realpath(__DIR__ . '/storage');
+});
+
+$runner->run('Datenbank initialisiert', function (PDO $pdo) {
+    if (!file_exists(DB_PATH)) {
+        throw new RuntimeException('database.sqlite wurde nicht erstellt.');
+    }
+    $tables = $pdo->query("SELECT name FROM sqlite_master WHERE type='table'")
+        ->fetchAll(PDO::FETCH_COLUMN);
+    $required = ['users', 'bands', 'requests', 'reviews', 'settings'];
+    foreach ($required as $table) {
+        if (!in_array($table, $tables, true)) {
+            throw new RuntimeException('Tabelle ' . $table . ' fehlt.');
+        }
+    }
+    return 'Tabellen gefunden: ' . implode(', ', $required);
+});
+
+$runner->run('Seed-Daten verfügbar', function (PDO $pdo) {
+    $users = (int) $pdo->query('SELECT COUNT(*) FROM users')->fetchColumn();
+    $bands = (int) $pdo->query('SELECT COUNT(*) FROM bands')->fetchColumn();
+    if ($users < 3 || $bands < 2) {
+        throw new RuntimeException('Seed-Daten unvollständig.');
+    }
+    return sprintf('Users: %d, Bands: %d', $users, $bands);
+});
+
+$runner->run('Login / Logout Workflow', function () {
+    if (!login('david@example.com', 'secret123')) {
+        throw new RuntimeException('Login schlug fehl.');
+    }
+    $user = currentUser();
+    if (!$user || $user['role'] !== 'kunde') {
+        throw new RuntimeException('Session liefert keinen Kunden.');
+    }
+    logout();
+    restartSession();
+    if (currentUser()) {
+        throw new RuntimeException('Logout hat Session nicht geleert.');
+    }
+    return 'Login erfolgreich für ' . $user['name'];
+});
+
+$runner->run('Band-Filter & Durchschnitt', function () {
+    $bands = allBands(['genre' => 'Funk']);
+    if (!$bands) {
+        throw new RuntimeException('Filter lieferte keine Band.');
+    }
+    $rating = averageRating((int) $bands[0]['id']);
+    if ($rating === null) {
+        throw new RuntimeException('Keine Bewertung vorhanden.');
+    }
+    return sprintf('%d Bands, Ø Bewertung %.1f★', count($bands), $rating);
+});
+
+$runner->run('Medien & Verfügbarkeiten geladen', function () {
+    $media = bandMedia(1);
+    $availability = bandAvailability(1);
+    $reviews = bandReviews(1);
+    if (!$media || !$availability || !$reviews) {
+        throw new RuntimeException('Band 1 hat unvollständige Daten.');
+    }
+    return sprintf('Medien: %d, Slots: %d, Reviews: %d', count($media), count($availability), count($reviews));
+});
+
+$runner->run('Anfrage speichern (Transaktion)', function (PDO $pdo) {
+    $before = (int) $pdo->query('SELECT COUNT(*) FROM requests')->fetchColumn();
+    createRequest([
+        'band_id' => 1,
+        'user_id' => 3,
+        'event_date' => (new DateTimeImmutable('+60 days'))->format('Y-m-d'),
+        'location' => 'Teststadt',
+        'budget' => 4500,
+        'event_type' => 'Testevent',
+        'message' => 'Funktionstest Anfrage',
+    ]);
+    $after = (int) $pdo->query('SELECT COUNT(*) FROM requests')->fetchColumn();
+    if ($after !== $before + 1) {
+        throw new RuntimeException('Anfrage wurde nicht gespeichert.');
+    }
+    return 'Requests gesamt (temporär): ' . $after;
+}, true);
+
+$runner->run('Bewertungen speichern & Eligibility', function (PDO $pdo) {
+    if (!eligibleForReview(1, 3)) {
+        throw new RuntimeException('User 3 sollte berechtigt sein.');
+    }
+    $before = (int) $pdo->query('SELECT COUNT(*) FROM reviews')->fetchColumn();
+    storeReview([
+        'band_id' => 1,
+        'user_id' => 3,
+        'rating' => 4,
+        'comment' => 'Testkommentar',
+    ]);
+    $after = (int) $pdo->query('SELECT COUNT(*) FROM reviews')->fetchColumn();
+    if ($after !== $before + 1) {
+        throw new RuntimeException('Review wurde nicht gespeichert.');
+    }
+    return 'Reviews gesamt (temporär): ' . $after;
+}, true);
+
+$runner->run('Einstellungen lesen & aktualisieren', function () {
+    $current = settings();
+    $originalFee = $current['service_fee'] ?? '0';
+    updateSetting('service_fee', '12');
+    $updated = settings();
+    if (($updated['service_fee'] ?? null) !== '12') {
+        throw new RuntimeException('Service Fee konnte nicht aktualisiert werden.');
+    }
+    updateSetting('service_fee', $originalFee);
+    return 'Service Fee temporär auf 12 gesetzt.';
+}, true);
+
+$runner->run('Moderations-Aktionen', function (PDO $pdo) {
+    changeBandStatus(1, 'prüfung');
+    $status = $pdo->query('SELECT status FROM bands WHERE id = 1')->fetchColumn();
+    if ($status !== 'prüfung') {
+        throw new RuntimeException('Bandstatus änderte sich nicht.');
+    }
+    changeReviewStatus(1, 'gesperrt');
+    $reviewStatus = $pdo->query('SELECT status FROM reviews WHERE id = 1')->fetchColumn();
+    if ($reviewStatus !== 'gesperrt') {
+        throw new RuntimeException('Reviewstatus änderte sich nicht.');
+    }
+    return 'Statusänderungen durchgeführt.';
+}, true);
+
+$runner->run('Registrierung legt Band an', function (PDO $pdo) {
+    $email = 'tester+' . uniqid('', true) . '@example.com';
+    $result = register([
+        'name' => 'Functional Tester',
+        'email' => $email,
+        'password' => 'secret123',
+        'role' => 'band',
+        'city' => 'Testingen',
+        'band_name' => 'QA Ensemble',
+        'genre' => 'QA Funk',
+    ]);
+    if (empty($result['token']) || strlen($result['token']) < 20) {
+        throw new RuntimeException('Verifikationstoken fehlt.');
+    }
+    $user = $pdo->prepare('SELECT id, role FROM users WHERE email = :email');
+    $user->execute([':email' => $email]);
+    $userRow = $user->fetch(PDO::FETCH_ASSOC);
+    if (!$userRow || $userRow['role'] !== 'band') {
+        throw new RuntimeException('User wurde nicht gespeichert.');
+    }
+    $band = $pdo->prepare('SELECT status FROM bands WHERE user_id = :id');
+    $band->execute([':id' => $userRow['id']]);
+    $bandRow = $band->fetch(PDO::FETCH_ASSOC);
+    if (!$bandRow || $bandRow['status'] !== 'prüfung') {
+        throw new RuntimeException('Bandprofil wurde nicht angelegt.');
+    }
+    return 'Token erstellt und Bandstatus "prüfung" bestätigt.';
+}, true);
+
+$runner->run('Startseite rendert fehlerfrei', function () {
+    $html = renderPage('index.php');
+    if (strpos($html, 'Aktive Bands') === false) {
+        throw new RuntimeException('Indexseite liefert keinen Inhalt.');
+    }
+    return 'HTML-Länge: ' . strlen($html) . ' Zeichen';
+});
+
+$runner->run('Band-Detailseite rendert', function () {
+    $html = renderPage('band-detail.php', ['id' => 1]);
+    if (strpos($html, 'Verfügbarkeit') === false) {
+        throw new RuntimeException('Band-Detailseite unvollständig.');
+    }
+    return 'HTML-Länge: ' . strlen($html) . ' Zeichen';
+});
+
+$runner->run('Anfrageformular rendert', function () {
+    $html = renderPage('anfrage.php', ['band_id' => 1]);
+    if (strpos($html, 'Anfrage an') === false) {
+        throw new RuntimeException('Anfrageformular fehlgeschlagen.');
+    }
+    return 'HTML-Länge: ' . strlen($html) . ' Zeichen';
+});
+
+$runner->run('E-Mail Logging (kein Versand)', function () {
+    $logDir = __DIR__ . '/storage/logs';
+    if (!is_dir($logDir)) {
+        mkdir($logDir, 0775, true);
+    }
+    $logFile = $logDir . '/mail.log';
+    $before = file_exists($logFile) ? filesize($logFile) : 0;
+    sendEmail('qa@example.com', 'Functional Test', 'Nur Logeintrag – kein Versand.');
+    $after = filesize($logFile);
+    if ($after <= $before) {
+        throw new RuntimeException('Mail-Log wurde nicht aktualisiert.');
+    }
+    return 'Logeintrag ergänzt, Versand erfolgt nur als Datei.';
+});
+
+$runner->summary();