diff --git a/backend/__init__.py b/backend/__init__.py
new file mode 100644
index 0000000..a510a25
--- /dev/null
+++ b/backend/__init__.py
@@ -0,0 +1,30 @@
+from bottle import request, response, Bottle
+from manager import Manager
+from json import dumps
+from pathlib import Path
+
+manager = Manager()
+app = Bottle()
+
+
+@app.post("/video")
+def add_videos():
+    manager.add_videos_by_number(request.json)
+    return "OK"
+
+
+@app.get("/progress")
+def get_progress():
+    response.content_type = "application/json"
+    return dumps(manager.get_progress())
+
+
+@app.post("/download")
+def download():
+    parent_dir = Path(request.json["parent_dir"])
+    id = request.json["id"]
+    try:
+        manager.download(id, parent_dir)
+        return "OK"
+    except:
+        return "Not ready"
diff --git a/manager/__init__.py b/manager/__init__.py
index b4f51e5..9acbb5e 100644
--- a/manager/__init__.py
+++ b/manager/__init__.py
@@ -7,15 +7,18 @@ from pathlib import Path
 class Manager:
     def __init__(self):
         self.video_list: list[Video] = []
+        self.bvid_set = set()
 
-    def add_videos_by_number(self, video_numbers: str):
-        for video_number in video_numbers.split():
+    def add_videos_by_number(self, video_numbers: list[str]):
+        for video_number in video_numbers:
             try:
                 video = Video(video_number)
             except:
                 continue
-            Thread(target=video.get_info).start()
-            self.video_list.append(video)
+            if (bvid := video.v.get_bvid()) not in self.bvid_set:
+                self.bvid_set.add(bvid)
+                self.video_list.append(video)
+                Thread(target=video.get_info).start()
 
     def download(self, id: int, parent_dir: str | Path = Path(".")):
         if isinstance(parent_dir, str):
diff --git a/poetry.lock b/poetry.lock
index 25c2ea7..f55778d 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -347,6 +347,23 @@ type = "legacy"
 url = "https://pypi.tuna.tsinghua.edu.cn/simple"
 reference = "mirrors"
 
+[[package]]
+name = "bottle"
+version = "0.12.23"
+description = "Fast and simple WSGI-framework for small web-applications."
+category = "main"
+optional = false
+python-versions = "*"
+files = [
+    {file = "bottle-0.12.23-py3-none-any.whl", hash = "sha256:9f1c363257c590bd34db5fad4693a7f06ff4217e9ad18337451de69c25137127"},
+    {file = "bottle-0.12.23.tar.gz", hash = "sha256:683de3aa399fb26e87b274dbcf70b1a651385d459131716387abdc3792e04167"},
+]
+
+[package.source]
+type = "legacy"
+url = "https://pypi.tuna.tsinghua.edu.cn/simple"
+reference = "mirrors"
+
 [[package]]
 name = "brotli"
 version = "1.0.9"
@@ -1653,4 +1670,4 @@ reference = "mirrors"
 [metadata]
 lock-version = "2.0"
 python-versions = "^3.11"
-content-hash = "b6c2ea94f40c44e176ac7606d5a83e0629e41489541d8677ad5fc898de9d89d2"
+content-hash = "355be7949f7315d306dda590f37dc6c75b8c29130154e934c9b50285807faab5"
diff --git a/pyproject.toml b/pyproject.toml
index 512813a..2e41b63 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -9,6 +9,7 @@ license = "GPL-3.0-only"
 python = "^3.11"
 bilibili-api-python = "^15.1.0"
 sanitize-filename = "^1.2.0"
+bottle = "^0.12.23"
 
 [tool.poetry.group.dev.dependencies]
 black = "^23.1.0"