diff --git a/src/main/infra/db.test.ts b/src/main/infra/db.test.ts
new file mode 100644
index 0000000..a609eb2
--- /dev/null
+++ b/src/main/infra/db.test.ts
@@ -0,0 +1,87 @@
+import { test, expect, describe, beforeEach, afterEach } from 'vitest';
+import * as fs from 'fs';
+import * as os from 'os';
+import * as path from 'path';
+import { openDatabase, type DbHandle } from './db';
+
+let tmpDir: string;
+let db: DbHandle | null = null;
+beforeEach(() => {
+    tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'db-test-'));
+});
+afterEach(() => {
+    try { db?.close(); } catch { /* ignore */ }
+    db = null;
+    try { fs.rmSync(tmpDir, { recursive: true, force: true }); } catch { /* ignore */ }
+});
+
+describe('openDatabase', () => {
+    test('creates a new file', () => {
+        const target = path.join(tmpDir, 'a.db');
+        db = openDatabase(target);
+        expect(fs.existsSync(target)).toBe(true);
+        expect(typeof db.run).toBe('function');
+        expect(typeof db.get).toBe('function');
+        expect(typeof db.all).toBe('function');
+        expect(typeof db.close).toBe('function');
+        expect(typeof db.transaction).toBe('function');
+        expect(typeof db.runBatch).toBe('function');
+    });
+
+    test('schema_meta row exists with schema_version=5', () => {
+        db = openDatabase(path.join(tmpDir, 'b.db'));
+        const row = db.get<{ value: string }>('SELECT value FROM schema_meta WHERE key = ?', ['schema_version']);
+        expect(row?.value).toBe('5');
+    });
+
+    test('WAL mode active', () => {
+        db = openDatabase(path.join(tmpDir, 'c.db'));
+        const row = db.get<{ journal_mode: string }>('PRAGMA journal_mode');
+        expect(row?.journal_mode).toBe('wal');
+    });
+
+    test('idempotent open: existing file keeps schema_version=5', () => {
+        const target = path.join(tmpDir, 'd.db');
+        db = openDatabase(target);
+        db.close();
+        db = openDatabase(target);
+        const row = db.get<{ value: string }>('SELECT value FROM schema_meta WHERE key = ?', ['schema_version']);
+        expect(row?.value).toBe('5');
+    });
+
+    test('run + get + all roundtrip on downloaded_vods', () => {
+        db = openDatabase(path.join(tmpDir, 'e.db'));
+        db.run('INSERT INTO downloaded_vods(vod_id) VALUES (?)', ['1234']);
+        db.run('INSERT INTO downloaded_vods(vod_id) VALUES (?)', ['5678']);
+        const one = db.get<{ vod_id: string }>('SELECT vod_id FROM downloaded_vods WHERE vod_id = ?', ['1234']);
+        expect(one?.vod_id).toBe('1234');
+        const all = db.all<{ vod_id: string }>('SELECT vod_id FROM downloaded_vods ORDER BY vod_id');
+        expect(all.map(r => r.vod_id)).toEqual(['1234', '5678']);
+    });
+
+    test('transaction commits as bracket', () => {
+        db = openDatabase(path.join(tmpDir, 'f.db'));
+        const handle = db;
+        const inserted = handle.transaction(() => {
+            handle.run('INSERT INTO downloaded_vods(vod_id) VALUES (?)', ['t1']);
+            handle.run('INSERT INTO downloaded_vods(vod_id) VALUES (?)', ['t2']);
+            return 2;
+        });
+        expect(inserted).toBe(2);
+        const c = handle.get<{ c: number }>('SELECT COUNT(*) AS c FROM downloaded_vods');
+        expect(c?.c).toBe(2);
+    });
+
+    test('transaction rolls back on throw', () => {
+        db = openDatabase(path.join(tmpDir, 'g.db'));
+        const handle = db;
+        expect(() => {
+            handle.transaction(() => {
+                handle.run('INSERT INTO downloaded_vods(vod_id) VALUES (?)', ['x1']);
+                throw new Error('boom');
+            });
+        }).toThrow('boom');
+        const c = handle.get<{ c: number }>('SELECT COUNT(*) AS c FROM downloaded_vods');
+        expect(c?.c).toBe(0);
+    });
+});
diff --git a/src/main/infra/db.ts b/src/main/infra/db.ts
new file mode 100644
index 0000000..4b75a49
--- /dev/null
+++ b/src/main/infra/db.ts
@@ -0,0 +1,60 @@
+import Database, { type Database as DatabaseT } from 'better-sqlite3';
+import { SCHEMA_V5_SQL } from './schema-v5';
+
+/**
+ * Public DB-Handle. Schmaler Wrapper um better-sqlite3.
+ */
+export interface DbHandle {
+    run(sql: string, params?: unknown[]): void;
+    get<T = unknown>(sql: string, params?: unknown[]): T | undefined;
+    all<T = unknown>(sql: string, params?: unknown[]): T[];
+    transaction<R>(fn: () => R): R;
+    runBatch(sql: string): void;
+    close(): void;
+    readonly raw: DatabaseT;
+}
+
+function splitStatements(sql: string): string[] {
+    return sql
+        .split(';')
+        .map(s => s.trim())
+        .filter(s => s.length > 0);
+}
+
+function runMultiStatement(db: DatabaseT, sql: string): void {
+    for (const stmt of splitStatements(sql)) {
+        db.prepare(stmt).run();
+    }
+}
+
+export function openDatabase(filePath: string): DbHandle {
+    const db = new Database(filePath);
+    db.pragma('journal_mode = WAL');
+    db.pragma('busy_timeout = 5000');
+    db.pragma('foreign_keys = ON');
+
+    runMultiStatement(db, SCHEMA_V5_SQL);
+
+    const handle: DbHandle = {
+        run(sql, params) {
+            db.prepare(sql).run(...(params ?? []) as unknown[]);
+        },
+        get<T>(sql: string, params?: unknown[]): T | undefined {
+            return db.prepare(sql).get(...(params ?? []) as unknown[]) as T | undefined;
+        },
+        all<T>(sql: string, params?: unknown[]): T[] {
+            return db.prepare(sql).all(...(params ?? []) as unknown[]) as T[];
+        },
+        transaction<R>(fn: () => R): R {
+            return db.transaction(fn)();
+        },
+        runBatch(sql) {
+            runMultiStatement(db, sql);
+        },
+        close() {
+            db.close();
+        },
+        get raw() { return db; },
+    };
+    return handle;
+}