diff --git a/.gitignore b/.gitignore
index 232c735..77a3132 100644
--- a/.gitignore
+++ b/.gitignore
@@ -25,5 +25,5 @@ aier_bot-*.tar
 # Temporary files, for example, from tests.
 /tmp/
 .DS_Store
-downloads
-dev.sh
\ No newline at end of file
+.local
+run.sh
\ No newline at end of file
diff --git a/lib/aier_bot/bot.ex b/lib/aier_bot/bot.ex
index d64438b..d317863 100644
--- a/lib/aier_bot/bot.ex
+++ b/lib/aier_bot/bot.ex
@@ -3,6 +3,8 @@ defmodule AierBot.Bot do
   alias AierBot.AierApi
   alias AierBot.OpenaiApi
 
+  alias AierBot.FileDownloader
+
   @bot :aier_bot
 
   use ExGram.Bot,
@@ -37,9 +39,11 @@ defmodule AierBot.Bot do
   def handle({:text, text, %{chat: chat}}, context) do
     # TODO: repeat
     # request download API
-    file_content = CobaltClient.json(text)
+    url = CobaltClient.json(text)
+    {file_name, file_content} = FileDownloader.download(url)
+
 
-    {:ok, message} = ExGram.send_document(chat.id, {:file_content, file_content, "video.mp4"})
+    {:ok, message} = ExGram.send_document(chat.id, {:file_content, file_content, file_name})
     IO.inspect(message)
 
     answer(context, "done")
diff --git a/lib/aier_bot/cobalt_client.ex b/lib/aier_bot/cobalt_client.ex
index 40efe21..01f304a 100644
--- a/lib/aier_bot/cobalt_client.ex
+++ b/lib/aier_bot/cobalt_client.ex
@@ -1,5 +1,4 @@
 defmodule AierBot.CobaltClient do
-  alias AierBot.FileDownloader
   use Tesla
 
   plug(Tesla.Middleware.BaseUrl, "https://api.cobalt.tools")
@@ -19,8 +18,7 @@ defmodule AierBot.CobaltClient do
         #   "url" => "https://video.twimg.com/amplify_video/1814202798097268736/vid/avc1/720x1192/HAD9zyJn1xoP4oRN.mp4?tag=16"
         # }
         %{"url" => url} = response.body
-        file_content = FileDownloader.download(url, "video.mp4")
-        file_content
+        url
 
       # TODO send photo to telegram
 
diff --git a/lib/aier_bot/file_downloader.ex b/lib/aier_bot/file_downloader.ex
index 9f30639..549a458 100644
--- a/lib/aier_bot/file_downloader.ex
+++ b/lib/aier_bot/file_downloader.ex
@@ -1,12 +1,24 @@
 defmodule AierBot.FileDownloader do
   use Tesla
 
-  def download(url, file_path) do
+  def download(url) do
+    # https://video.twimg.com/amplify_video/1814202798097268736/vid/avc1/720x1192/HAD9zyJn1xoP4oRN.mp4?tag=16
+
+    IO.puts(url)
     case get(url) do
-      {:ok, %Tesla.Env{status: 200, body: body}} ->
-        File.write("./downloads/#{file_path}", body)
+      {:ok, %Tesla.Env{status: 200, body: body, headers: headers}} ->
+        # TODO: 可以使用异步，并且实时更新 bot 状态
+        IO.puts("Downloading file...")
+
+        # [..., {"content-type", "video/mp4"}, ...] = headers
+        utc_now_str = DateTime.utc_now() |> DateTime.shift_zone!("Etc/UTC") |> DateTime.to_iso8601()
+        content_type = headers |> Enum.find(fn {k, _} -> k == "content-type" end) |> elem(1)
+        # IO.puts("Content-Type: #{content_type}")
+        file_path = utc_now_str <> "_" <> content_type |> String.replace("/", ".")
+
+        File.write("./.local/storage/#{file_path}", body)
         IO.puts("File downloaded successfully.")
-        body
+        {file_path, body}
 
       {:ok, %Tesla.Env{status: status}} ->
         IO.puts("Failed to download file. Status: #{status}")