diff --git a/gnes/client/cli.py b/gnes/client/cli.py
index ebee67d7..6e701416 100644
--- a/gnes/client/cli.py
+++ b/gnes/client/cli.py
@@ -28,9 +28,24 @@
 class CLIClient(GrpcClient):
     def __init__(self, args, start_at_init: bool = True):
         super().__init__(args)
+        self._bytes_generator = self._get_bytes_generator_from_args(args)
         if start_at_init:
             self.start()
 
+    @staticmethod
+    def _get_bytes_generator_from_args(args):
+        if args.txt_file:
+            all_bytes = (v.encode() for v in args.txt_file)
+        elif args.image_zip_file:
+            zipfile_ = zipfile.ZipFile(args.image_zip_file)
+            all_bytes = (zipfile_.open(v).read() for v in zipfile_.namelist())
+        elif args.video_zip_file:
+            zipfile_ = zipfile.ZipFile(args.video_zip_file)
+            all_bytes = (zipfile_.open(v).read() for v in zipfile_.namelist())
+        else:
+            all_bytes = None
+        return all_bytes
+
     def start(self):
         try:
             getattr(self, self.args.mode)()
@@ -72,18 +87,16 @@ def query_callback(self, req: 'gnes_pb2.Request', resp: 'gnes_pb2.Response'):
 
     @property
     def bytes_generator(self) -> Generator[bytes, None, None]:
-        if self.args.txt_file:
-            all_bytes = (v.encode() for v in self.args.txt_file)
-        elif self.args.image_zip_file:
-            zipfile_ = zipfile.ZipFile(self.args.image_zip_file)
-            all_bytes = (zipfile_.open(v).read() for v in zipfile_.namelist())
-        elif self.args.video_zip_file:
-            zipfile_ = zipfile.ZipFile(self.args.video_zip_file)
-            all_bytes = (zipfile_.open(v).read() for v in zipfile_.namelist())
+        if self.bytes_generator:
+            return self._bytes_generator
         else:
-            raise AttributeError('--txt_file, --image_zip_file, --video_zip_file one must be given')
+            raise ValueError('bytes_generator is empty or not set')
 
-        return all_bytes
+    @bytes_generator.setter
+    def bytes_generator(self, bytes_gen: Generator[bytes, None, None]):
+        if self._bytes_generator:
+            self.logger.warning('bytes_generator is not empty, overrided')
+        self._bytes_generator = bytes_gen
 
 
 class ProgressBar:
diff --git a/gnes/flow/__init__.py b/gnes/flow/__init__.py
index e9d8ff70..5c15f5ce 100644
--- a/gnes/flow/__init__.py
+++ b/gnes/flow/__init__.py
@@ -1,7 +1,7 @@
 from collections import OrderedDict, defaultdict
 from contextlib import ExitStack
 from functools import wraps
-from typing import Union, Tuple, List, Optional
+from typing import Union, Tuple, List, Optional, Generator
 
 from ..cli.parser import set_router_parser, set_indexer_parser, \
     set_frontend_parser, set_preprocessor_parser, \
@@ -63,7 +63,6 @@ class BuildLevel(BetterEnum):
         EMPTY = 0
         GRAPH = 1
         RUNTIME = 2
-        RUNTIME_WITH_CLIENT = 3
 
     def __init__(self, with_frontend: bool = True, **kwargs):
         self.logger = set_logger(self.__class__.__name__)
@@ -127,21 +126,25 @@ def to_mermaid(self, left_right: bool = True):
             'copy-paste the output and visualize it with: https://mermaidjs.github.io/mermaid-live-editor/')
         return mermaid_str
 
-    def train(self, **kwargs):
-        self._call_client(mode='train', **kwargs)
+    def train(self, bytes_gen: Generator[bytes, None, None] = None, **kwargs):
+        self._call_client(bytes_gen, mode='train', **kwargs)
 
-    def index(self, **kwargs):
-        self._call_client(mode='index', **kwargs)
+    def index(self, bytes_gen: Generator[bytes, None, None] = None, **kwargs):
+        self._call_client(bytes_gen, mode='index', **kwargs)
 
-    def query(self, **kwargs):
-        self._call_client(mode='query', **kwargs)
+    def query(self, bytes_gen: Generator[bytes, None, None] = None, **kwargs):
+        self._call_client(bytes_gen, mode='query', **kwargs)
 
     @_build_level(BuildLevel.RUNTIME)
-    def _call_client(self, **kwargs):
+    def _call_client(self, bytes_gen: Generator[bytes, None, None] = None, **kwargs):
         args, p_args = self._get_parsed_args(set_client_cli_parser(), kwargs)
         p_args.grpc_port = self._service_nodes[self._frontend]['parsed_args'].grpc_port
         p_args.grpc_host = self._service_nodes[self._frontend]['parsed_args'].grpc_host
-        CLIClient(p_args)
+        c = CLIClient(p_args, start_at_init=False)
+        if bytes_gen:
+            c.bytes_generator = bytes_gen
+        with c:
+            pass
 
     def add_frontend(self, *args, **kwargs) -> 'Flow':
         """Add a frontend to the current flow, a shortcut of add(Service.Frontend)
@@ -383,4 +386,4 @@ def __enter__(self):
 
     def __exit__(self, exc_type, exc_val, exc_tb):
         if hasattr(self, '_service_stack'):
-            self._service_stack.close()
+            self._service_stack.close()
\ No newline at end of file
diff --git a/tests/test_gnes_flow.py b/tests/test_gnes_flow.py
index e1546bbd..ab797fbf 100644
--- a/tests/test_gnes_flow.py
+++ b/tests/test_gnes_flow.py
@@ -31,11 +31,12 @@ def test_flow1_ctx_empty(self):
             pass
 
     def test_flow1_ctx(self):
-        flow = (Flow(check_version=False, route_table=True)
+        flow = (Flow(check_version=False, route_table=False)
                 .add(gfs.Router, yaml_path='BaseRouter'))
-        with flow(backend='process') as f:
-            # CLIClient(self.index_args)
+        with flow(backend='process') as f, open(self.test_file) as fp:
             f.index(txt_file=self.test_file, batch_size=4)
+            f.index(bytes_gen=(v.encode() for v in fp), batch_size=4)
+            f.train(txt_file=self.test_file, batch_size=4)
 
     def test_flow2(self):
         f = (Flow(check_version=False, route_table=True)