diff --git a/lib/save_it/bot.ex b/lib/save_it/bot.ex
index 2c6feb1..e9f20d7 100644
--- a/lib/save_it/bot.ex
+++ b/lib/save_it/bot.ex
@@ -25,14 +25,17 @@ defmodule SaveIt.Bot do
     setup_commands: true
 
   command("start")
+
   command("search", description: "Search photos")
   command("similar", description: "Find similar photos")
-  command("about", description: "About the bot")
+  command("delete", description: "Delete message")
 
   command("login", description: "Login")
   command("code", description: "Get code for login")
   command("folder", description: "Update Google Drive folder ID")
 
+  command("about", description: "Know more about this bot")
+
   middleware(ExGram.Middleware.IgnoreUsername)
 
   def bot(), do: @bot
@@ -43,11 +46,11 @@ defmodule SaveIt.Bot do
 
   def handle({:command, :about, _msg}, context) do
     answer(context, """
-    This bot is created by @ThaddeusJiang, feel free to contact me if you have any questions.
+    SaveIt can download images and videos, just give me a link.
 
-    GitHub: https://github.com/ThaddeusJiang
-    Blog: https://thaddeusjiang.com
-    X: https://x.com/thaddeusjiang
+    Created by @ThaddeusJiang, powered by Cobalt, Typesense, and Elixir.Access
+
+    Give a star ⭐ if you like it, https://github.com/ThaddeusJiang/save_it
     """)
   end
 
@@ -137,7 +140,25 @@ defmodule SaveIt.Bot do
   end
 
   def handle({:command, :similar, %{chat: chat, photo: nil}}, _context) do
-    send_message(chat.id, "Upload a photo to find similar photos.")
+    send_message(chat.id, "Upload a photo with /similar for finding similar photos.")
+  end
+
+  def handle({:command, :delete, %{chat: chat, reply_to_message: nil}}, _ctx) do
+    send_message(chat.id, "reply a message with /delete command.")
+  end
+
+  def handle(
+        {:command, :delete,
+         %{chat: chat, message_id: message_id, from: from, reply_to_message: reply_to_message}},
+        _ctx
+      ) do
+    {:ok, %{id: bot_id, username: bot_username}} = ExGram.get_me()
+
+    if Enum.member?([bot_id, from.id], reply_to_message.from.id) do
+      handle_delete_command(chat.id, message_id, reply_to_message)
+    else
+      send_message(chat.id, "Only delete messages from @#{bot_username} and yourself.")
+    end
   end
 
   # caption: nil -> find same photos
@@ -467,4 +488,23 @@ defmodule SaveIt.Bot do
         """)
     end
   end
+
+  defp handle_delete_command(chat_id, message_id, reply_to_message) do
+    case reply_to_message do
+      %{photo: nil} ->
+        delete_message(chat_id, reply_to_message.message_id)
+
+      %{photo: photo} ->
+        photo
+        |> Enum.map(& &1.file_id)
+        |> PhotoService.delete_photos()
+
+        delete_message(chat_id, reply_to_message.message_id)
+
+      _ ->
+        send_message(chat_id, "reply a message with /delete command.")
+    end
+
+    delete_message(chat_id, message_id)
+  end
 end
diff --git a/lib/save_it/migration/typesense.ex b/lib/save_it/migration/typesense.ex
index 9ad8a9d..0097c95 100644
--- a/lib/save_it/migration/typesense.ex
+++ b/lib/save_it/migration/typesense.ex
@@ -24,11 +24,11 @@ defmodule SaveIt.Migration.Typesense do
     Typesense.handle_response!(res)
   end
 
-  def delete_collection!(collection_name) do
+  def delete_collection(collection_name) do
     req = build_request("/collections/#{collection_name}")
-    res = Req.delete!(req)
+    res = Req.delete(req)
 
-    Typesense.handle_response!(res)
+    Typesense.handle_response(res)
   end
 
   defp get_env() do
diff --git a/lib/save_it/migration/typesense/photo.ex b/lib/save_it/migration/typesense/photo.ex
index a401728..1f94701 100644
--- a/lib/save_it/migration/typesense/photo.ex
+++ b/lib/save_it/migration/typesense/photo.ex
@@ -37,7 +37,8 @@ defmodule SaveIt.Migration.Typesense.Photo do
 
     Typesense.update_collection!(@collection_name, %{
       "fields" => [
-        %{"name" => "file_id", "type" => "string", "optional" => true}
+        %{"name" => "file_id", "type" => "string", "optional" => true},
+        %{"name" => "url", "drop" => true}
       ]
     })
   end
@@ -66,12 +67,12 @@ defmodule SaveIt.Migration.Typesense.Photo do
     Logger.info("migrated #{count} photos")
   end
 
-  def drop_photos!() do
-    Typesense.delete_collection!(@collection_name)
+  def drop_photos() do
+    Typesense.delete_collection(@collection_name)
   end
 
   def reset!() do
-    drop_photos!()
+    drop_photos()
     create_photos_20241024!()
     migrate_photos_20241029!()
   end
diff --git a/lib/save_it/photo_service.ex b/lib/save_it/photo_service.ex
index 8331aca..fda9767 100644
--- a/lib/save_it/photo_service.ex
+++ b/lib/save_it/photo_service.ex
@@ -36,6 +36,14 @@ defmodule SaveIt.PhotoService do
     end
   end
 
+  def delete_photo(file_id) do
+    Typesense.delete_document_by_query("photos", "file_id:[#{file_id}]")
+  end
+
+  def delete_photos(file_ids) do
+    Typesense.delete_document_by_query("photos", "file_id:[#{Enum.join(file_ids, ",")}]")
+  end
+
   def get_photo(photo_id) do
     Typesense.get_document("photos", photo_id)
   end
diff --git a/lib/small_sdk/typesense.ex b/lib/small_sdk/typesense.ex
index 05ab2bc..a18e3dd 100644
--- a/lib/small_sdk/typesense.ex
+++ b/lib/small_sdk/typesense.ex
@@ -63,13 +63,23 @@ defmodule SmallSdk.Typesense do
     handle_response(res)
   end
 
-  def delete_document!(collection_name, document_id) do
+  def delete_document(collection_name, document_id) do
     req = build_request("/collections/#{collection_name}/documents/#{document_id}")
     res = Req.delete(req)
 
     handle_response(res)
   end
 
+  # docs: https://typesense.org/docs/27.1/api/documents.html#delete-documents
+  def delete_document_by_query(collection_name, filter_by, opts \\ []) do
+    batch_size = Keyword.get(opts, :batch_size, 100)
+
+    req = build_request("/collections/#{collection_name}/documents")
+
+    Req.delete(req, params: %{"filter_by" => filter_by, "batch_size" => batch_size})
+    |> handle_response()
+  end
+
   def create_search_key() do
     {url, _} = get_env()
     req = build_request("/keys")
diff --git a/lib/small_sdk/web_downloader.ex b/lib/small_sdk/web_downloader.ex
index 096bd27..2179875 100644
--- a/lib/small_sdk/web_downloader.ex
+++ b/lib/small_sdk/web_downloader.ex
@@ -1,10 +1,7 @@
 defmodule SmallSdk.WebDownloader do
   require Logger
 
-  # FIXME:TODAY return {:ok, file_name, file_content} | {:error, reason}
   def download_files(urls) do
-    Logger.info("download_files started, urls: #{inspect(urls)}")
-
     res =
       urls
       |> Enum.map(&download_file/1)
@@ -13,7 +10,10 @@ defmodule SmallSdk.WebDownloader do
         {:error, reason}, _ -> {:halt, {:error, reason}}
       end)
 
-    {:ok, res}
+    case res do
+      {:error, reason} -> {:error, reason}
+      files -> {:ok, files}
+    end
   end
 
   # TODO: have to handle Stream data
diff --git a/priv/typesense/2024-10-29_photos_url_to_file_id.ex b/priv/typesense/2024-10-29_photos_url_to_file_id.ex
index 1358964..90e938c 100644
--- a/priv/typesense/2024-10-29_photos_url_to_file_id.ex
+++ b/priv/typesense/2024-10-29_photos_url_to_file_id.ex
@@ -1 +1,2 @@
+# mix run priv/typesense/2024-10-29_photos_url_to_file_id.ex
 SaveIt.Migration.Typesense.Photo.migrate_photos_20241029!()