diff --git a/MANUAL_PIPELINE_GUIDE.md b/MANUAL_PIPELINE_GUIDE.md
index e92e6da..0e87e3e 100644
--- a/MANUAL_PIPELINE_GUIDE.md
+++ b/MANUAL_PIPELINE_GUIDE.md
@@ -98,8 +98,17 @@ background_video = "minecraft"    # Video nền
 background_audio = "lofi"         # Audio nền
 background_audio_volume = 0.15    # Âm lượng audio nền (0 = tắt)
 max_video_length = 120            # Max thời lượng video (giây)
+watermark_enabled = true          # Enable/disable watermark overlay
+watermark_path = "assets/backgrounds/transparent-bg.png"  # Path to watermark PNG file
 ```
 
+**Watermark:**
+- `watermark_enabled`: Set to `true` để thêm watermark vào tất cả videos, `false` để tắt
+- `watermark_path`: Đường dẫn tới file PNG watermark (mặc định: `assets/transparent-bg.png`)
+  - File phải có kích thước 1080×1920 pixels với alpha transparency
+  - Vùng transparent sẽ hiển thị video phía dưới
+  - Watermark xuất hiện suốt thời lượng của video
+
 TTS engine được lấy từ section `[settings.tts]` trong `config.toml`. Mặc định dùng **GoogleTranslate** (không cần API key).
 
 ---
diff --git a/TTS/OhFreeMe.py b/TTS/OhFreeMe.py
index 2f9b904..a3ca218 100644
--- a/TTS/OhFreeMe.py
+++ b/TTS/OhFreeMe.py
@@ -16,7 +16,7 @@ load_dotenv()
 
 OHFREEME_API_URL = os.getenv("OHFREEME_API_URL", "")
 OHFREEME_BASE_URL = os.getenv("OHFREEME_BASE_URL", "")
-JWT_TOKEN = os.getenv("OHFREEME_JWT_TOKEN", "")
+OHFREEME_JWT_TOKEN = os.getenv("OHFREEME_JWT_TOKEN", "")
 VOICES_FILE = Path(__file__).resolve().parent.parent / "config" / "ohfreeme_voices.json"
 MAX_RETRIES = 3
 RATE_LIMIT_WAIT = 10
@@ -101,13 +101,16 @@ class OhFreeMe:
             "pitch": settings.config["settings"]["tts"].get("ohfreeme_pitch", 0),
         }
         headers = {
-            "accept": "*/*",
             "cache-control": "no-cache",
             "content-type": "application/json",
-            "origin": OHFREEME_BASE_URL,
-            "cookie": f"auth_token={JWT_TOKEN}",
-            "referer": OHFREEME_BASE_URL,
-            "user-agent": self._pick_user_agent(),
+            "accept": "*/*",
+            "accept-language": "en-GB,en-US;q=0.9,en;q=0.8,vi;q=0.7", # important
+            "sec-fetch-mode": "cors", # important
+            "sec-fetch-site": "same-origin", # important
+            "Cookie": f"auth_token={OHFREEME_JWT_TOKEN}", # important
+            "user-agent": self._pick_user_agent(), # important
+            # "origin": OHFREEME_BASE_URL,
+            # "referer": f"{OHFREEME_BASE_URL}/",
         }
 
         # streaming NDJSON response with debug logging
@@ -138,7 +141,7 @@ class OhFreeMe:
                     continue
                 # debug: print raw line (decoded) to terminal
                 if data.get("status") == "done":
-                    print_substep(f"[OhFreeMe debug] Received line: {data}", style="blue")
+                    print_substep(f"[OhFreeMe debug] Received")
                     return self._extract_audio(data)
 
         raise RuntimeError(f"OhFreeMe TTS failed after {MAX_RETRIES} retries (rate limited)")
diff --git a/manual/video_builder.py b/manual/video_builder.py
index b11ff5d..6ad5f7e 100644
--- a/manual/video_builder.py
+++ b/manual/video_builder.py
@@ -111,6 +111,10 @@ class ManualVideoBuilder:
         # Output settings
         self.output_dir = Path(self.config.get("output_dir", "manual_results"))
 
+        # Watermark settings
+        self.watermark_enabled = self.config.get("watermark_enabled", True)
+        self.watermark_path = Path(self.config.get("watermark_path", "assets/backgrounds/transparent-bg.png"))
+
     def build(self) -> str:
         """Build the final video.
 
@@ -189,12 +193,24 @@ class ManualVideoBuilder:
             )
             current_time += s["audio_duration"]
 
-        # Step 7: Render
+        # Step 7: Overlay watermark (if enabled)
+        if self.watermark_enabled and self.watermark_path.exists():
+            print_step("🎨 Applying watermark...")
+            watermark_input = ffmpeg.input(str(self.watermark_path))["v"]
+            background_clip = background_clip.overlay(
+                watermark_input,
+                x=0,
+                y=0,
+            )
+        elif self.watermark_enabled and not self.watermark_path.exists():
+            print_substep(f"Warning: Watermark enabled but file not found: {self.watermark_path}", style="yellow")
+
+        # Step 8: Render
         print_step("🎥 Rendering the video...")
         self.output_dir.mkdir(parents=True, exist_ok=True)
 
         # Normalize filename
-        filename = self._normalize_filename(self.post.get("title", self.post_id))
+        filename = self._normalize_filename(self.post_id)
         output_path = str(self.output_dir / f"{filename}.mp4")
         # Prevent path too long
         if len(output_path) > 251:
diff --git a/manual_main.py b/manual_main.py
index 4e351e1..74dd68b 100644
--- a/manual_main.py
+++ b/manual_main.py
@@ -50,7 +50,9 @@ MANUAL_DEFAULTS = {
     "background_audio_dir": "assets/backgrounds/audio",
     "background_audio_volume": 0.1,
     "max_video_length": 120,
-    "screenshot_width_percent": 85
+    "screenshot_width_percent": 85,
+    "watermark_enabled": True,
+    "watermark_path": "assets/backgrounds/transparent-bg.png",
 }
 
 # Full default settings.config that TTS engines and shared modules expect.