diff --git a/nanobot/channels/feishu.py b/nanobot/channels/feishu.py
index 0a0a5e4..7d26fa8 100644
--- a/nanobot/channels/feishu.py
+++ b/nanobot/channels/feishu.py
@@ -16,26 +16,9 @@ from nanobot.bus.queue import MessageBus
 from nanobot.channels.base import BaseChannel
 from nanobot.config.schema import FeishuConfig
 
-try:
-    import lark_oapi as lark
-    from lark_oapi.api.im.v1 import (
-        CreateFileRequest,
-        CreateFileRequestBody,
-        CreateImageRequest,
-        CreateImageRequestBody,
-        CreateMessageReactionRequest,
-        CreateMessageReactionRequestBody,
-        CreateMessageRequest,
-        CreateMessageRequestBody,
-        Emoji,
-        GetMessageResourceRequest,
-        P2ImMessageReceiveV1,
-    )
-    FEISHU_AVAILABLE = True
-except ImportError:
-    FEISHU_AVAILABLE = False
-    lark = None
-    Emoji = None
+import importlib.util
+
+FEISHU_AVAILABLE = importlib.util.find_spec("lark_oapi") is not None
 
 # Message type display mapping
 MSG_TYPE_MAP = {
@@ -280,6 +263,7 @@ class FeishuChannel(BaseChannel):
             logger.error("Feishu app_id and app_secret not configured")
             return
 
+        import lark_oapi as lark
         self._running = True
         self._loop = asyncio.get_running_loop()
 
@@ -340,6 +324,7 @@ class FeishuChannel(BaseChannel):
 
     def _add_reaction_sync(self, message_id: str, emoji_type: str) -> None:
         """Sync helper for adding reaction (runs in thread pool)."""
+        from lark_oapi.api.im.v1 import CreateMessageReactionRequest, CreateMessageReactionRequestBody, Emoji
         try:
             request = CreateMessageReactionRequest.builder() \
                 .message_id(message_id) \
@@ -364,7 +349,7 @@ class FeishuChannel(BaseChannel):
 
         Common emoji types: THUMBSUP, OK, EYES, DONE, OnIt, HEART
         """
-        if not self._client or not Emoji:
+        if not self._client:
             return
 
         loop = asyncio.get_running_loop()
@@ -456,6 +441,7 @@ class FeishuChannel(BaseChannel):
 
     def _upload_image_sync(self, file_path: str) -> str | None:
         """Upload an image to Feishu and return the image_key."""
+        from lark_oapi.api.im.v1 import CreateImageRequest, CreateImageRequestBody
         try:
             with open(file_path, "rb") as f:
                 request = CreateImageRequest.builder() \
@@ -479,6 +465,7 @@ class FeishuChannel(BaseChannel):
 
     def _upload_file_sync(self, file_path: str) -> str | None:
         """Upload a file to Feishu and return the file_key."""
+        from lark_oapi.api.im.v1 import CreateFileRequest, CreateFileRequestBody
         ext = os.path.splitext(file_path)[1].lower()
         file_type = self._FILE_TYPE_MAP.get(ext, "stream")
         file_name = os.path.basename(file_path)
@@ -506,6 +493,7 @@ class FeishuChannel(BaseChannel):
 
     def _download_image_sync(self, message_id: str, image_key: str) -> tuple[bytes | None, str | None]:
         """Download an image from Feishu message by message_id and image_key."""
+        from lark_oapi.api.im.v1 import GetMessageResourceRequest
         try:
             request = GetMessageResourceRequest.builder() \
                 .message_id(message_id) \
@@ -530,6 +518,7 @@ class FeishuChannel(BaseChannel):
         self, message_id: str, file_key: str, resource_type: str = "file"
     ) -> tuple[bytes | None, str | None]:
         """Download a file/audio/media from a Feishu message by message_id and file_key."""
+        from lark_oapi.api.im.v1 import GetMessageResourceRequest
         try:
             request = (
                 GetMessageResourceRequest.builder()
@@ -598,6 +587,7 @@ class FeishuChannel(BaseChannel):
 
     def _send_message_sync(self, receive_id_type: str, receive_id: str, msg_type: str, content: str) -> bool:
         """Send a single message (text/image/file/interactive) synchronously."""
+        from lark_oapi.api.im.v1 import CreateMessageRequest, CreateMessageRequestBody
         try:
             request = CreateMessageRequest.builder() \
                 .receive_id_type(receive_id_type) \
diff --git a/pyproject.toml b/pyproject.toml
index 0546523..d384f3f 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -42,6 +42,7 @@ dependencies = [
     "prompt-toolkit>=3.0.50,<4.0.0",
     "mcp>=1.26.0,<2.0.0",
     "json-repair>=0.57.0,<1.0.0",
+    "chardet>=3.0.2,<6.0.0",
 ]
 
 [project.optional-dependencies]