diff --git a/src/cli_demo.py b/src/cli_demo.py
index 39704153..09d444c6 100644
--- a/src/cli_demo.py
+++ b/src/cli_demo.py
@@ -13,7 +13,7 @@ except ImportError:
 
 def main():
     chat_model = ChatModel()
-    history = []
+    messages = []
     print("Welcome to the CLI application, use `clear` to remove the history, use `exit` to exit the application.")
 
     while True:
@@ -37,12 +37,13 @@ def main():
         print("Assistant: ", end="", flush=True)
 
         response = ""
-        for new_text in chat_model.stream_chat(query, history):
+        for new_text in chat_model.stream_chat(messages):
             print(new_text, end="", flush=True)
             response += new_text
         print()
 
-        history = history + [(query, response)]
+        messages.append({"role": "user", "content": query})
+        messages.append({"role": "assistant", "content": response})
 
 
 if __name__ == "__main__":
diff --git a/src/llmtuner/chat/chat_model.py b/src/llmtuner/chat/chat_model.py
index f6cbbddc..cfa2700b 100644
--- a/src/llmtuner/chat/chat_model.py
+++ b/src/llmtuner/chat/chat_model.py
@@ -1,11 +1,11 @@
 from dataclasses import dataclass
 from threading import Thread
-from typing import Any, Dict, Generator, List, Literal, Optional, Tuple
+from typing import Any, Dict, Generator, List, Literal, Optional, Sequence, Tuple
 
 import torch
 from transformers import GenerationConfig, TextIteratorStreamer
 
-from ..data import Role, get_template_and_fix_tokenizer
+from ..data import get_template_and_fix_tokenizer
 from ..extras.misc import get_logits_processor
 from ..hparams import get_infer_args
 from ..model import dispatch_model, load_model_and_tokenizer
@@ -32,20 +32,11 @@ class ChatModel:
 
     def _process_args(
         self,
-        query: str,
-        history: Optional[List[Tuple[str, str]]] = None,
+        messages: Sequence[Dict[str, str]],
         system: Optional[str] = None,
         tools: Optional[str] = None,
         **input_kwargs,
     ) -> Tuple[Dict[str, Any], int]:
-        messages = []
-        if history is not None:
-            for old_prompt, old_response in history:
-                messages.append({"role": Role.USER, "content": old_prompt})
-                messages.append({"role": Role.ASSISTANT, "content": old_response})
-
-        messages.append({"role": Role.USER, "content": query})
-        messages.append({"role": Role.ASSISTANT, "content": ""})
         prompt, _ = self.template.encode_oneturn(
             tokenizer=self.tokenizer, messages=messages, system=system, tools=tools
         )
@@ -97,18 +88,12 @@ class ChatModel:
     @torch.inference_mode()
     def chat(
         self,
-        query: str,
-        history: Optional[List[Tuple[str, str]]] = None,
+        messages: Sequence[Dict[str, str]],
         system: Optional[str] = None,
         tools: Optional[str] = None,
         **input_kwargs,
     ) -> List[Response]:
-        r"""
-        Args: query, history, system, **input_kwargs
-
-        Returns: [(response_text, prompt_length, response_length)] * n (default n=1)
-        """
-        gen_kwargs, prompt_length = self._process_args(query, history, system, tools, **input_kwargs)
+        gen_kwargs, prompt_length = self._process_args(messages, system, tools, **input_kwargs)
         generate_output = self.model.generate(**gen_kwargs)
         response_ids = generate_output[:, prompt_length:]
         response = self.tokenizer.batch_decode(
@@ -132,13 +117,12 @@ class ChatModel:
     @torch.inference_mode()
     def stream_chat(
         self,
-        query: str,
-        history: Optional[List[Tuple[str, str]]] = None,
+        messages: Sequence[Dict[str, str]],
         system: Optional[str] = None,
         tools: Optional[str] = None,
         **input_kwargs,
     ) -> Generator[str, None, None]:
-        gen_kwargs, _ = self._process_args(query, history, system, tools, **input_kwargs)
+        gen_kwargs, _ = self._process_args(messages, system, tools, **input_kwargs)
         streamer = TextIteratorStreamer(self.tokenizer, timeout=60.0, skip_prompt=True, skip_special_tokens=True)
         gen_kwargs["streamer"] = streamer
 
diff --git a/src/llmtuner/data/formatter.py b/src/llmtuner/data/formatter.py
index 6451d8e3..078539c2 100644
--- a/src/llmtuner/data/formatter.py
+++ b/src/llmtuner/data/formatter.py
@@ -1,6 +1,11 @@
 import json
-from dataclasses import dataclass
-from typing import Any, Dict, List, Literal, Union
+import re
+from abc import ABC, abstractmethod
+from dataclasses import dataclass, field
+from typing import Any, Dict, List, Literal, Set, Sequence, Tuple, Union
+
+
+SLOTS = Sequence[Union[str, Set[str], Dict[str, str]]]
 
 
 JSON_FORMAT_PROMPT = (
@@ -18,30 +23,85 @@ TOOL_SYSTEM_PROMPT = (
 )
 
 
-@dataclass
-class StringFormatter:
-    container: List[Union[str, Dict[str, str]]]
+def default_tool_formatter(tools: List[Dict[str, Any]]) -> str:
+    tool_text = ""
+    tool_names = []
+    for tool in tools:
+        param_text = ""
+        for name, param in tool["parameters"]["properties"].items():
+            required = ", required" if name in tool["parameters"].get("required", []) else ""
+            enum = ", should be one of [{}]".format(", ".join(param["enum"])) if param.get("enum", None) else ""
+            param_text += "  - {name} ({type}{required}): {desc}{enum}\n".format(
+                name=name,
+                type=param.get("type", ""),
+                required=required,
+                desc=param.get("description", ""),
+                enum=enum,
+            )
 
-    def __call__(self, **kwargs) -> List[Union[str, Dict[str, str]]]:
+        tool_text += "> Tool Name: {name}\nTool Description: {desc}\nTool Args:\n{args}\n".format(
+            name=tool["name"], desc=tool.get("description", ""), args=param_text
+        )
+        tool_names.append(tool["name"])
+
+    return TOOL_SYSTEM_PROMPT.format(
+        tool_text=tool_text, tool_names=", ".join(tool_names), format_prompt=JSON_FORMAT_PROMPT
+    )
+
+
+def default_tool_extractor(content: str) -> Union[str, Tuple[str, str]]:
+    regex = re.compile(r"Action:\s*([a-zA-Z0-9_]+).*?Action Input:\s*(.*)", re.DOTALL)
+    action_match = re.search(regex, content)
+    if not action_match:
+        return content
+
+    tool_name = action_match.group(1).strip()
+    tool_input = action_match.group(2).strip().strip('"').strip("```")
+    try:
+        arguments = json.loads(tool_input)
+    except json.JSONDecodeError:
+        return content
+
+    return tool_name, json.dumps(arguments, ensure_ascii=False)
+
+
+@dataclass
+class Formatter(ABC):
+    slots: SLOTS = field(default_factory=list)
+    tool_format: Literal["default"] = "default"
+
+    @abstractmethod
+    def apply(self, **kwargs) -> SLOTS:
+        ...
+
+
+@dataclass
+class EmptyFormatter(Formatter):
+    def apply(self, **kwargs) -> SLOTS:
+        return self.slots
+
+
+@dataclass
+class StringFormatter(Formatter):
+    def apply(self, **kwargs) -> SLOTS:
         elements = []
-        for elem in self.container:
-            if isinstance(elem, str):
+        for slot in self.slots:
+            if isinstance(slot, str):
                 for name, value in kwargs.items():
-                    elem = elem.replace("{{" + name + "}}", value)
-                elements.append(elem)
-            elif isinstance(elem, (dict, set)):
-                elements.append(elem)
+                    slot = slot.replace("{{" + name + "}}", value, 1)
+                elements.append(slot)
+            elif isinstance(slot, (dict, set)):
+                elements.append(slot)
             else:
-                raise ValueError("Input must be string, set[str] or dict[str, str], got {}".format(type(elem)))
+                raise ValueError("Input must be string, set[str] or dict[str, str], got {}".format(type(slot)))
 
         return elements
 
 
 @dataclass
-class FunctionFormatter:
-    container: List[Union[str, Dict[str, str]]]
-
-    def __call__(self, content: str) -> List[Union[str, Dict[str, str]]]:
+class FunctionFormatter(Formatter):
+    def apply(self, **kwargs) -> SLOTS:
+        content = kwargs.pop("content")
         try:
             function = json.loads(content)
             name = function["name"]
@@ -50,55 +110,36 @@ class FunctionFormatter:
             name, arguments = "", ""
 
         elements = []
-        for elem in self.container:
-            if isinstance(elem, str):
-                elem = elem.replace("{{name}}", name)
-                elem = elem.replace("{{arguments}}", arguments)
-                elements.append(elem)
-            elif isinstance(elem, (dict, set)):
-                elements.append(elem)
+        for slot in self.slots:
+            if isinstance(slot, str):
+                slot = slot.replace("{{name}}", name).replace("{{arguments}}", arguments)
+                elements.append(slot)
+            elif isinstance(slot, (dict, set)):
+                elements.append(slot)
             else:
-                raise ValueError("Input must be string, set[str] or dict[str, str], got {}".format(type(elem)))
+                raise ValueError("Input must be string, set[str] or dict[str, str], got {}".format(type(slot)))
 
         return elements
 
 
 @dataclass
-class ToolFormatter:
-    type: Literal["default"]
-
-    def _default(self, tools: List[Dict[str, Any]]) -> str:
-        tool_text = ""
-        tool_names = []
-        for tool in tools:
-            param_text = ""
-            for name, param in tool["parameters"]["properties"].items():
-                required = ", required" if name in tool["parameters"].get("required", []) else ""
-                enum = ", should be one of [{}]".format(", ".join(param["enum"])) if param.get("enum", None) else ""
-                param_text += "  - {name} ({type}{required}): {desc}{enum}\n".format(
-                    name=name,
-                    type=param.get("type", ""),
-                    required=required,
-                    desc=param.get("description", ""),
-                    enum=enum,
-                )
-
-            tool_text += "> Tool Name: {name}\nTool Description: {desc}\nTool Args:\n{args}\n".format(
-                name=tool["name"], desc=tool.get("description", ""), args=param_text
-            )
-            tool_names.append(tool["name"])
-
-        return TOOL_SYSTEM_PROMPT.format(
-            tool_text=tool_text, tool_names=", ".join(tool_names), format_prompt=JSON_FORMAT_PROMPT
-        )
-
-    def __call__(self, content: str) -> List[Union[str, Dict[str, str]]]:
+class ToolFormatter(Formatter):
+    def apply(self, **kwargs) -> SLOTS:
+        content = kwargs.pop("content")
         try:
             tools = json.loads(content)
             if not len(tools):
                 return [""]
 
-            if self.type == "default":
-                return [self._default(tools)]
+            if self.tool_format == "default":
+                return [default_tool_formatter(tools)]
+            else:
+                raise NotImplementedError
         except Exception:
             return [""]
+
+    def extract(self, content: str) -> Union[str, Tuple[str, str]]:
+        if self.tool_format == "default":
+            return default_tool_extractor(content)
+        else:
+            raise NotImplementedError
diff --git a/src/llmtuner/data/template.py b/src/llmtuner/data/template.py
index 924007bd..77d053f3 100644
--- a/src/llmtuner/data/template.py
+++ b/src/llmtuner/data/template.py
@@ -1,31 +1,34 @@
 from dataclasses import dataclass
-from typing import TYPE_CHECKING, Callable, Dict, List, Optional, Tuple, Union
+from typing import TYPE_CHECKING, Dict, List, Optional, Sequence, Tuple, Union
 
 from ..extras.logging import get_logger
-from .formatter import FunctionFormatter, StringFormatter, ToolFormatter
-from .utils import Role
+from .formatter import EmptyFormatter, FunctionFormatter, StringFormatter, ToolFormatter
+from .utils import Role, infer_max_len
 
 
 if TYPE_CHECKING:
     from transformers import PreTrainedTokenizer
 
+    from .formatter import Formatter
+
 
 logger = get_logger(__name__)
 
 
 @dataclass
 class Template:
-    format_user: Callable
-    format_assistant: Callable
-    format_system: Callable
-    format_tool: Callable
-    format_observation: Callable
-    format_function: Callable
-    system: str
-    separator: List[Union[str, Dict[str, str]]]
+    format_user: "Formatter"
+    format_assistant: "Formatter"
+    format_system: "Formatter"
+    format_function: "Formatter"
+    format_observation: "Formatter"
+    format_tools: "Formatter"
+    format_separator: "Formatter"
+    default_system: str
     stop_words: List[str]
     efficient_eos: bool
     replace_eos: bool
+    force_system: bool
 
     def encode_oneturn(
         self,
@@ -34,14 +37,15 @@ class Template:
         system: Optional[str] = None,
         tools: Optional[str] = None,
         cutoff_len: Optional[int] = 1_000_000,
+        reserved_label_len: Optional[int] = 16,
     ) -> Tuple[List[int], List[int]]:
         r"""
         Returns a single pair of token ids representing prompt and response respectively.
         """
-        encoded_pairs = self._encode(tokenizer, messages, system, tools, cutoff_len)
+        encoded_pairs = self._encode(tokenizer, messages, system, tools, cutoff_len, reserved_label_len)
         prompt_ids = []
         for query_ids, resp_ids in encoded_pairs[:-1]:
-            prompt_ids = prompt_ids + query_ids + resp_ids
+            prompt_ids += query_ids + resp_ids
         prompt_ids = prompt_ids + encoded_pairs[-1][0]
         answer_ids = encoded_pairs[-1][1]
         return prompt_ids, answer_ids
@@ -50,15 +54,15 @@ class Template:
         self,
         tokenizer: "PreTrainedTokenizer",
         messages: List[Dict[str, str]],
-        system: str,
-        tools: str,
+        system: Optional[str] = None,
+        tools: Optional[str] = None,
         cutoff_len: Optional[int] = 1_000_000,
-    ) -> List[Tuple[List[int], List[int]]]:
+        reserved_label_len: Optional[int] = 16,
+    ) -> Sequence[Tuple[List[int], List[int]]]:
         r"""
         Returns multiple pairs of token ids representing prompts and responses respectively.
         """
-        encoded_pairs = self._encode(tokenizer, messages, system, tools, cutoff_len)
-        return encoded_pairs
+        return self._encode(tokenizer, messages, system, tools, cutoff_len, reserved_label_len)
 
     def _encode(
         self,
@@ -67,48 +71,37 @@ class Template:
         system: str,
         tools: str,
         cutoff_len: int,
-    ) -> List[Tuple[List[int], List[int]]]:
+        reserved_label_len: int,
+    ) -> Sequence[Tuple[List[int], List[int]]]:
         r"""
         Encodes formatted inputs to pairs of token ids.
-        Turn 0: system + query        resp + eos
-        Turn t: sep + query           resp + eos
+        Turn 0: system + query        resp
+        Turn t: sep + query           resp
         """
-        system = system or self.system
+        system = system or self.default_system
         encoded_messages = []
         for i, message in enumerate(messages):
             elements = []
-            if i == 0 and (system or tools):
-                tool_text = self.format_tool(content=tools)[0] if tools else ""
-                elements += self.format_system(content=(system + tool_text))
+            if i == 0 and (system or tools or self.force_system):
+                tool_text = self.format_tools.apply(content=tools)[0] if tools else ""
+                elements += self.format_system.apply(content=(system + tool_text))
             elif i > 0 and i % 2 == 0:
-                elements += self.separator
+                elements += self.format_separator.apply()
 
             if message["role"] == Role.USER:
-                elements += self.format_user(content=message["content"], idx=str(i // 2))
+                elements += self.format_user.apply(content=message["content"], idx=str(i // 2))
             elif message["role"] == Role.ASSISTANT:
-                elements += self.format_assistant(content=message["content"])
+                elements += self.format_assistant.apply(content=message["content"])
             elif message["role"] == Role.OBSERVATION:
-                elements += self.format_observation(content=message["content"])
+                elements += self.format_observation.apply(content=message["content"])
             elif message["role"] == Role.FUNCTION:
-                elements += self.format_function(content=message["content"])
+                elements += self.format_function.apply(content=message["content"])
+            else:
+                raise NotImplementedError
 
             encoded_messages.append(self._convert_elements_to_ids(tokenizer, elements))
 
-        # TODO: need to improve
-        encoded_pairs = []
-        total_length = 0
-        for i in range(0, len(encoded_messages), 2):
-            if total_length >= cutoff_len:
-                break
-
-            encoded_messages[i] = encoded_messages[i][: cutoff_len - total_length]
-            total_length += len(encoded_messages[i])
-
-            encoded_messages[i + 1] = encoded_messages[i + 1][: max(1, cutoff_len - total_length)]
-            total_length += len(encoded_messages[i + 1])
-            encoded_pairs.append((encoded_messages[i], encoded_messages[i + 1]))
-
-        return encoded_pairs
+        return self._make_pairs(encoded_messages, cutoff_len, reserved_label_len)
 
     def _convert_elements_to_ids(
         self, tokenizer: "PreTrainedTokenizer", elements: List[Union[str, Dict[str, str]]]
@@ -120,19 +113,44 @@ class Template:
         for elem in elements:
             if isinstance(elem, str):
                 if len(elem) != 0:
-                    token_ids = token_ids + tokenizer.encode(elem, add_special_tokens=False)
+                    token_ids += tokenizer.encode(elem, add_special_tokens=False)
             elif isinstance(elem, dict):
-                token_ids = token_ids + [tokenizer.convert_tokens_to_ids(elem.get("token"))]
+                token_ids += [tokenizer.convert_tokens_to_ids(elem.get("token"))]
             elif isinstance(elem, set):
                 if "bos_token" in elem and tokenizer.bos_token_id:
-                    token_ids = token_ids + [tokenizer.bos_token_id]
+                    token_ids += [tokenizer.bos_token_id]
                 elif "eos_token" in elem and tokenizer.eos_token_id:
-                    token_ids = token_ids + [tokenizer.eos_token_id]
+                    token_ids += [tokenizer.eos_token_id]
             else:
                 raise ValueError("Input must be string, set[str] or dict[str, str], got {}".format(type(elem)))
 
         return token_ids
 
+    def _make_pairs(
+        self,
+        encoded_messages: Sequence[List[int]],
+        cutoff_len: int,
+        reserved_label_len: int,
+    ) -> Sequence[Tuple[List[int], List[int]]]:
+        encoded_pairs = []
+        total_length = 0
+        for i in range(0, len(encoded_messages), 2):
+            if total_length >= cutoff_len:
+                break
+
+            max_source_len, max_target_len = infer_max_len(
+                source_len=len(encoded_messages[i]),
+                target_len=len(encoded_messages[i + 1]),
+                cutoff_len=(cutoff_len - total_length),
+                reserved_label_len=reserved_label_len,
+            )
+            encoded_messages[i] = encoded_messages[i][: max_source_len]
+            encoded_messages[i + 1] = encoded_messages[i + 1][: max_target_len]
+            total_length += len(encoded_messages[i]) + len(encoded_messages[i + 1])
+            encoded_pairs.append((encoded_messages[i], encoded_messages[i + 1]))
+
+        return encoded_pairs
+
 
 @dataclass
 class Llama2Template(Template):
@@ -143,49 +161,38 @@ class Llama2Template(Template):
         system: str,
         tools: str,
         cutoff_len: int,
-    ) -> List[Tuple[List[int], List[int]]]:
+        reserved_label_len: int,
+    ) -> Sequence[Tuple[List[int], List[int]]]:
         r"""
         Encodes formatted inputs to pairs of token ids.
-        Turn 0: system + query        resp + eos
-        Turn t: sep + query           resp + eos
+        Turn 0: system + query        resp
+        Turn t: sep + query           resp
         """
-        system = system or self.system
+        system = system or self.default_system
         encoded_messages = []
         for i, message in enumerate(messages):
             elements = []
             system_text = ""
-            if i == 0 and (system or tools):
-                tool_text = self.format_tool(content=tools)[0] if tools else ""
-                system_text = self.format_system(content=(system + tool_text))[0]
+            if i == 0 and (system or tools or self.force_system):
+                tool_text = self.format_tools.apply(content=tools)[0] if tools else ""
+                system_text = self.format_system.apply(content=(system + tool_text))[0]
             elif i > 0 and i % 2 == 0:
-                elements += self.separator
+                elements += self.format_separator.apply()
 
             if message["role"] == Role.USER:
-                elements += self.format_user(content=system_text + message["content"], idx=str(i // 2))
+                elements += self.format_user.apply(content=system_text + message["content"])
             elif message["role"] == Role.ASSISTANT:
-                elements += self.format_assistant(content=message["content"])
+                elements += self.format_assistant.apply(content=message["content"])
             elif message["role"] == Role.OBSERVATION:
-                elements += self.format_observation(content=message["content"])
+                elements += self.format_observation.apply(content=message["content"])
             elif message["role"] == Role.FUNCTION:
-                elements += self.format_function(content=message["content"])
+                elements += self.format_function.apply(content=message["content"])
+            else:
+                raise NotImplementedError
 
             encoded_messages.append(self._convert_elements_to_ids(tokenizer, elements))
 
-        # TODO: need to improve
-        encoded_pairs = []
-        total_length = 0
-        for i in range(0, len(encoded_messages), 2):
-            if total_length >= cutoff_len:
-                break
-
-            encoded_messages[i] = encoded_messages[i][: cutoff_len - total_length]
-            total_length += len(encoded_messages[i])
-
-            encoded_messages[i + 1] = encoded_messages[i + 1][: max(1, cutoff_len - total_length)]
-            total_length += len(encoded_messages[i + 1])
-            encoded_pairs.append((encoded_messages[i], encoded_messages[i + 1]))
-
-        return encoded_pairs
+        return self._make_pairs(encoded_messages, cutoff_len, reserved_label_len)
 
 
 templates: Dict[str, Template] = {}
@@ -193,32 +200,39 @@ templates: Dict[str, Template] = {}
 
 def register_template(
     name: str,
-    format_user: Optional[Callable] = None,
-    format_assistant: Optional[Callable] = None,
-    format_system: Optional[Callable] = None,
-    format_tool: Optional[Callable] = None,
-    format_observation: Optional[Callable] = None,
-    format_function: Optional[Callable] = None,
-    system: Optional[str] = "",
-    separator: Optional[List[Union[str, Dict[str, str]]]] = "",
+    format_user: Optional["Formatter"] = None,
+    format_assistant: Optional["Formatter"] = None,
+    format_system: Optional["Formatter"] = None,
+    format_function: Optional["Formatter"] = None,
+    format_observation: Optional["Formatter"] = None,
+    format_tools: Optional["Formatter"] = None,
+    format_separator: Optional["Formatter"] = None,
+    default_system: Optional[str] = "",
     stop_words: Optional[List[str]] = [],
     efficient_eos: Optional[bool] = False,
     replace_eos: Optional[bool] = False,
+    force_system: Optional[bool] = False,
 ) -> None:
+    eos_slots = [] if efficient_eos else [{"eos_token"}]
     template_class = Llama2Template if name.startswith("llama2") else Template
+    default_user_formatter = StringFormatter(slots=["{{content}}"])
+    default_assistant_formatter = StringFormatter(slots=["{{content}}"] + eos_slots)
+    default_function_formatter = FunctionFormatter(slots=["Action: {{name}}\nAction Input: {{arguments}}"] + eos_slots)
+    default_tool_formatter = ToolFormatter(slots="default")
+    default_separator_formatter = EmptyFormatter()
     templates[name] = template_class(
-        format_user=format_user or StringFormatter(container=["{{content}}"]),
-        format_assistant=format_assistant or StringFormatter(container=["{{content}}", {"eos_token"}]),
-        format_system=format_system or StringFormatter(container=["{{content}}"]),
-        format_tool=format_tool or ToolFormatter(type="default"),
-        format_observation=format_observation or format_user,
-        format_function=format_function
-        or FunctionFormatter(container=["Action: {{name}}\nAction Input: {{arguments}}", {"eos_token"}]),
-        system=system,
-        separator=separator,
+        format_user=format_user or default_user_formatter,
+        format_assistant=format_assistant or default_assistant_formatter,
+        format_system=format_system or default_user_formatter,
+        format_function=format_function or default_function_formatter,
+        format_observation=format_observation or format_user or default_user_formatter,
+        format_tools=format_tools or default_tool_formatter,
+        format_separator=format_separator or default_separator_formatter,
+        default_system=default_system,
         stop_words=stop_words,
         efficient_eos=efficient_eos,
         replace_eos=replace_eos,
+        force_system=force_system,
     )
 
 
@@ -257,23 +271,22 @@ def get_template_and_fix_tokenizer(name: str, tokenizer: "PreTrainedTokenizer")
 
 register_template(
     name="alpaca",
-    format_user=StringFormatter(container=["### Instruction:\n{{content}}\n\n### Response:\n"]),
-    system=(
+    format_user=StringFormatter(slots=["### Instruction:\n{{content}}\n\n### Response:\n"]),
+    format_separator=EmptyFormatter(slots=["\n\n"]),
+    default_system=(
         "Below is an instruction that describes a task. " "Write a response that appropriately completes the request."
     ),
-    separator=["\n\n"],
 )
 
 
 register_template(
     name="aquila",
-    format_user=StringFormatter(container=["Human: {{content}}###Assistant:"]),
-    format_assistant=StringFormatter(container=["{{content}}"]),
-    system=(
+    format_user=StringFormatter(slots=["Human: {{content}}###Assistant:"]),
+    format_separator=EmptyFormatter(slots=["###"]),
+    default_system=(
         "A chat between a curious human and an artificial intelligence assistant. "
         "The assistant gives helpful, detailed, and polite answers to the human's questions."
     ),
-    separator=["###"],
     stop_words=["</s>"],
     efficient_eos=True,
 )
@@ -281,51 +294,53 @@ register_template(
 
 register_template(
     name="baichuan",
-    format_user=StringFormatter(container=[{"token": "<reserved_102>"}, "{{content}}", {"token": "<reserved_103>"}]),
-    format_assistant=StringFormatter(container=["{{content}}"]),
+    format_user=StringFormatter(slots=[{"token": "<reserved_102>"}, "{{content}}", {"token": "<reserved_103>"}]),
     efficient_eos=True,
 )
 
 
 register_template(
     name="baichuan2",
-    format_user=StringFormatter(container=[{"token": "<reserved_106>"}, "{{content}}", {"token": "<reserved_107>"}]),
-    format_assistant=StringFormatter(container=["{{content}}"]),
+    format_user=StringFormatter(slots=[{"token": "<reserved_106>"}, "{{content}}", {"token": "<reserved_107>"}]),
     efficient_eos=True,
 )
 
 
 register_template(
-    name="belle", format_user=StringFormatter(container=["Human: {{content}}\n\nBelle: "]), separator=["\n\n"]
+    name="belle",
+    format_user=StringFormatter(slots=["Human: {{content}}\n\nBelle: "]),
+    format_system=StringFormatter(slots=[{"bos_token"}, "{{content}}"]),
+    format_separator=EmptyFormatter(slots=["\n\n"]),
+    force_system=True,
 )
 
 
 register_template(
     name="bluelm",
-    format_user=StringFormatter(container=[{"token": "[|Human|]:"}, "{{content}}", {"token": "[|AI|]:"}]),
+    format_user=StringFormatter(slots=[{"token": "[|Human|]:"}, "{{content}}", {"token": "[|AI|]:"}]),
 )
 
 
 register_template(
     name="chatglm2",
-    format_user=StringFormatter(container=["[Round {{idx}}]\n\n问：{{content}}\n\n答："]),
-    format_assistant=StringFormatter(container=["{{content}}"]),
-    format_system=StringFormatter(container=[{"token": "[gMASK]"}, {"token": "sop"}, "{{content}}"]),
-    separator=["\n\n"],
+    format_user=StringFormatter(slots=["[Round {{idx}}]\n\n问：{{content}}\n\n答："]),
+    format_system=StringFormatter(slots=[{"token": "[gMASK]"}, {"token": "sop"}, "{{content}}"]),
+    format_separator=EmptyFormatter(slots=["\n\n"]),
     efficient_eos=True,
+    force_system=True,
 )
 
 
 register_template(
     name="chatglm3",
-    format_user=StringFormatter(container=[{"token": "<|user|>"}, "\n", "{{content}}", {"token": "<|assistant|>"}]),
-    format_assistant=StringFormatter(container=["\n" "{{content}}"]),
+    format_user=StringFormatter(slots=[{"token": "<|user|>"}, "\n", "{{content}}", {"token": "<|assistant|>"}]),
+    format_assistant=StringFormatter(slots=["\n", "{{content}}"]),
     format_system=StringFormatter(
-        container=[{"token": "[gMASK]"}, {"token": "sop"}, {"token": "<|system|>"}, "\n", "{{content}}"]
+        slots=[{"token": "[gMASK]"}, {"token": "sop"}, {"token": "<|system|>"}, "\n", "{{content}}"]
     ),
-    format_observation=StringFormatter(container=[{"token": "<|observation|>"}, "\n", "{{content}}"]),
-    format_function=FunctionFormatter(container=["{{name}}\n{{arguments}}"]),
-    system=(
+    format_function=FunctionFormatter(slots=["{{name}}\n{{arguments}}"]),
+    format_observation=StringFormatter(slots=[{"token": "<|observation|>"}, "\n", "{{content}}"]),
+    default_system=(
         "You are ChatGLM3, a large language model trained by Zhipu.AI. "
         "Follow the user's instructions carefully. Respond using markdown."
     ),
@@ -335,24 +350,30 @@ register_template(
 
 
 register_template(
-    name="codegeex2", format_system=StringFormatter(container=[{"token": "[gMASK]"}, {"token": "sop"}, "{{content}}"])
+    name="codegeex2",
+    format_system=StringFormatter(slots=[{"token": "[gMASK]"}, {"token": "sop"}, "{{content}}"]),
+    force_system=True,
 )
 
 
-register_template(name="deepseek", format_user=StringFormatter(container=["User: {{content}}\n\nAssistant:"]))
+register_template(
+    name="deepseek",
+    format_user=StringFormatter(slots=["User: {{content}}\n\nAssistant:"]),
+    format_system=StringFormatter(slots=[{"bos_token"}, "{{content}}"]),
+    force_system=True,
+)
 
 
 register_template(
     name="deepseekcoder",
-    format_user=StringFormatter(container=["### Instruction:\n{{content}}\n### Response:\n"]),
-    format_assistant=StringFormatter(container=["{{content}}"]),
-    system=(
+    format_user=StringFormatter(slots=["### Instruction:\n{{content}}\n### Response:\n"]),
+    format_separator=EmptyFormatter(slots=["\n", {"token": "<|EOT|>"}, "\n"]),
+    default_system=(
         "You are an AI programming assistant, utilizing the Deepseek Coder model, "
         "developed by Deepseek Company, and you only answer questions related to computer science. "
         "For politically sensitive questions, security and privacy issues, "
         "and other non-computer science questions, you will refuse to answer\n"
     ),
-    separator=["\n", {"token": "<|EOT|>"}, "\n"],
     stop_words=["<|EOT|>"],
     efficient_eos=True,
 )
@@ -360,29 +381,23 @@ register_template(
 
 register_template(
     name="default",
-    format_user=StringFormatter(container=["Human: {{content}}\nAssistant: "]),
-    system=(
-        "A chat between a curious user and an artificial intelligence assistant. "
-        "The assistant gives helpful, detailed, and polite answers to the user's questions.\n"
-    ),
-    separator=["\n"],
+    format_user=StringFormatter(slots=["Human: {{content}}\nAssistant: "]),
+    format_separator=EmptyFormatter(slots=["\n"]),
 )
 
 
 register_template(
     name="falcon",
-    format_user=StringFormatter(container=["User: {{content}}\nFalcon:"]),
-    format_assistant=StringFormatter(container=["{{content}}"]),
-    separator=["\n"],
+    format_user=StringFormatter(slots=["User: {{content}}\nFalcon:"]),
+    format_separator=EmptyFormatter(slots=["\n"]),
     efficient_eos=True,
 )
 
 
 register_template(
     name="intern",
-    format_user=StringFormatter(container=["<|User|>:{{content}}", {"token": "<eoh>"}, "\n<|Bot|>:"]),
-    format_assistant=StringFormatter(container=["{{content}}"]),
-    separator=[{"token": "<eoa>"}, "\n"],
+    format_user=StringFormatter(slots=["<|User|>:{{content}}", {"token": "<eoh>"}, "\n<|Bot|>:"]),
+    format_separator=EmptyFormatter(slots=[{"token": "<eoa>"}, "\n"]),
     stop_words=["<eoa>"],
     efficient_eos=True,
 )
@@ -390,38 +405,26 @@ register_template(
 
 register_template(
     name="intern2",
-    format_user=StringFormatter(
-        container=[
-            {"token": "[UNUSED_TOKEN_146]"},
-            "user\n{{content}}",
-            {"token": "[UNUSED_TOKEN_145]"},
-            "\n",
-            {"token": "[UNUSED_TOKEN_146]"},
-            "assistant\n",
-        ]
-    ),
-    format_assistant=StringFormatter(container=["{{content}}"]),
-    format_system=StringFormatter(
-        container=[{"token": "[UNUSED_TOKEN_146]"}, "system\n{{content}}", {"token": "[UNUSED_TOKEN_145]"}, "\n"]
-    ),
-    system=(
+    format_user=StringFormatter(slots=["<|im_start|>user\n{{content}}<|im_end|>\n<|im_start|>assistant\n"]),
+    format_system=StringFormatter(slots=[{"bos_token"}, "<|im_start|>system\n{{content}}<|im_end|>\n"]),
+    format_separator=EmptyFormatter(slots=["\n"]),
+    default_system=(
         "You are an AI assistant whose name is InternLM (书生·浦语).\n"
         "- InternLM (书生·浦语) is a conversational language model that is developed "
         "by Shanghai AI Laboratory (上海人工智能实验室). It is designed to be helpful, honest, and harmless.\n"
         "- InternLM (书生·浦语) can understand and communicate fluently in the language chosen "
         "by the user such as English and 中文."
     ),
-    separator=[{"token": "[UNUSED_TOKEN_145]"}, "\n"],
-    stop_words=["[UNUSED_TOKEN_145]"],
-    efficient_eos=True,
+    stop_words=["<|im_end|>"],
+    replace_eos=True,
 )
 
 
 register_template(
     name="llama2",
-    format_user=StringFormatter(container=["[INST] {{content}} [/INST]"]),
-    format_system=StringFormatter(container=["<<SYS>>\n{{content}}\n<</SYS>>\n\n"]),
-    system=(
+    format_user=StringFormatter(slots=[{"bos_token"}, "[INST] {{content}} [/INST]"]),
+    format_system=StringFormatter(slots=["<<SYS>>\n{{content}}\n<</SYS>>\n\n"]),
+    default_system=(
         "You are a helpful, respectful and honest assistant. "
         "Always answer as helpfully as possible, while being safe. "
         "Your answers should not include any harmful, unethical, "
@@ -436,51 +439,60 @@ register_template(
 
 register_template(
     name="llama2_zh",
-    format_user=StringFormatter(container=["[INST] {{content}} [/INST]"]),
-    format_system=StringFormatter(container=["<<SYS>>\n{{content}}\n<</SYS>>\n\n"]),
-    system="You are a helpful assistant. 你是一个乐于助人的助手。",
+    format_user=StringFormatter(slots=[{"bos_token"}, "[INST] {{content}} [/INST]"]),
+    format_system=StringFormatter(slots=["<<SYS>>\n{{content}}\n<</SYS>>\n\n"]),
+    default_system="You are a helpful assistant. 你是一个乐于助人的助手。",
 )
 
 
-register_template(name="mistral", format_user=StringFormatter(container=["[INST] {{content}} [/INST]"]))
+register_template(
+    name="mistral",
+    format_user=StringFormatter(slots=["[INST] {{content}} [/INST]"]),
+    format_system=StringFormatter(slots=[{"bos_token"}, "{{content}}"]),
+    force_system=True,
+)
 
 
 register_template(
     name="openchat",
     format_user=StringFormatter(
-        container=["GPT4 Correct User: {{content}}", {"token": "<|end_of_turn|>"}, "GPT4 Correct Assistant:"]
+        slots=["GPT4 Correct User: {{content}}", {"eos_token"}, "GPT4 Correct Assistant:"]
     ),
-    format_assistant=StringFormatter(container=["{{content}}"]),
-    separator=[{"token": "<|end_of_turn|>"}],
-    stop_words=["<|end_of_turn|>"],
-    efficient_eos=True,
+    format_assistant=StringFormatter(slots=["{{content}}"]),
+    format_system=StringFormatter(slots=[{"bos_token"}, "{{content}}"]),
+    force_system=True,
 )
 
 
 register_template(
     name="qwen",
-    format_user=StringFormatter(container=["<|im_start|>user\n{{content}}<|im_end|>\n<|im_start|>assistant\n"]),
-    format_system=StringFormatter(container=["<|im_start|>system\n{{content}}<|im_end|>\n"]),
-    system="You are a helpful assistant.",
-    separator=["\n"],
+    format_user=StringFormatter(slots=["<|im_start|>user\n{{content}}<|im_end|>\n<|im_start|>assistant\n"]),
+    format_system=StringFormatter(slots=["<|im_start|>system\n{{content}}<|im_end|>\n"]),
+    format_separator=EmptyFormatter(slots=["\n"]),
+    default_system="You are a helpful assistant.",
     stop_words=["<|im_end|>"],
     replace_eos=True,
 )
 
 
-register_template(name="solar", format_user=StringFormatter(container=["### User:\n{{content}}\n\n### Assistant:\n"]))
+register_template(
+    name="solar",
+    format_user=StringFormatter(slots=["### User:\n{{content}}\n\n### Assistant:\n"]),
+    format_system=StringFormatter(slots=["### System:\n{{content}}\n\n"]),
+    efficient_eos=True,
+)
 
 
 register_template(
     name="starchat",
     format_user=StringFormatter(
-        container=[{"token": "<|user|>"}, "\n{{content}}", {"token": "<|end|>"}, "\n", {"token": "<|assistant|>"}]
+        slots=[{"token": "<|user|>"}, "\n{{content}}", {"token": "<|end|>"}, "\n", {"token": "<|assistant|>"}]
     ),
-    format_assistant=StringFormatter(container=["{{content}}"]),
-    format_system=StringFormatter(container=[{"token": "<|system|>"}, "\n{{content}}", {"token": "<|end|>"}, "\n"]),
-    separator=[{"token": "<|end|>"}, "\n"],
+    format_system=StringFormatter(slots=[{"token": "<|system|>"}, "\n{{content}}", {"token": "<|end|>"}, "\n"]),
+    format_separator=EmptyFormatter(slots=["\n"]),
     stop_words=["<|end|>"],
-    efficient_eos=True,
+    replace_eos=True,
+    force_system=True,
 )
 
 
@@ -489,8 +501,8 @@ register_template(name="vanilla")
 
 register_template(
     name="vicuna",
-    format_user=StringFormatter(container=["USER: {{content}} ASSISTANT:"]),
-    system=(
+    format_user=StringFormatter(slots=["USER: {{content}} ASSISTANT:"]),
+    default_system=(
         "A chat between a curious user and an artificial intelligence assistant. "
         "The assistant gives helpful, detailed, and polite answers to the user's questions."
     ),
@@ -499,8 +511,8 @@ register_template(
 
 register_template(
     name="xuanyuan",
-    format_user=StringFormatter(container=["Human: {{content}} Assistant:"]),
-    system=(
+    format_user=StringFormatter(slots=["Human: {{content}} Assistant:"]),
+    default_system=(
         "以下是用户和人工智能助手之间的对话。用户以Human开头，人工智能助手以Assistant开头，"
         "会对人类提出的问题给出有帮助、高质量、详细和礼貌的回答，并且总是拒绝参与与不道德、"
         "不安全、有争议、政治敏感等相关的话题、问题和指示。\n"
@@ -508,14 +520,15 @@ register_template(
 )
 
 
-register_template(name="xverse", format_user=StringFormatter(container=["Human: {{content}}\n\nAssistant: "]))
+register_template(name="xverse", format_user=StringFormatter(slots=["Human: {{content}}\n\nAssistant: "]))
 
 
 register_template(
     name="yayi",
-    format_user=StringFormatter(container=[{"token": "<|Human|>"}, ":\n{{content}}\n\n", {"token": "<|YaYi|>"}, ":"]),
-    format_system=StringFormatter(container=[{"token": "<|System|>"}, ":\n{{content}}\n\n"]),
-    system=(
+    format_user=StringFormatter(slots=[{"token": "<|Human|>"}, ":\n{{content}}\n\n", {"token": "<|YaYi|>"}, ":"]),
+    format_system=StringFormatter(slots=[{"token": "<|System|>"}, ":\n{{content}}\n\n"]),
+    format_separator=EmptyFormatter(slots=["\n\n"]),
+    default_system=(
         "You are a helpful, respectful and honest assistant named YaYi "
         "developed by Beijing Wenge Technology Co.,Ltd. "
         "Always answer as helpfully as possible, while being safe.  "
@@ -526,15 +539,14 @@ register_template(
         "explain why instead of answering something not correct. "
         "If you don't know the answer to a question, please don't share false information."
     ),
-    separator=["\n\n"],
     stop_words=["<|End|>"],
 )
 
 
 register_template(
     name="yi",
-    format_user=StringFormatter(container=["<|im_start|>user\n{{content}}<|im_end|>\n<|im_start|>assistant\n"]),
-    separator=["\n"],
+    format_user=StringFormatter(slots=["<|im_start|>user\n{{content}}<|im_end|>\n<|im_start|>assistant\n"]),
+    format_separator=EmptyFormatter(slots=["\n"]),
     stop_words=["<|im_end|>"],
     replace_eos=True,
 )
@@ -542,8 +554,8 @@ register_template(
 
 register_template(
     name="yuan",
-    format_user=StringFormatter(container=["{{content}}", {"token": "<sep>"}]),
-    separator=["\n"],
+    format_user=StringFormatter(slots=["{{content}}", {"token": "<sep>"}]),
+    format_separator=EmptyFormatter(slots=["\n"]),
     stop_words=["<eod>"],
     replace_eos=True,
 )
@@ -551,18 +563,14 @@ register_template(
 
 register_template(
     name="zephyr",
-    format_user=StringFormatter(container=["<|user|>\n{{content}}</s><|assistant|>"]),
-    format_system=StringFormatter(
-        container=[
-            "<|system|>\n{{content}}</s>",
-        ]
-    ),
-    system="You are a friendly chatbot who always responds in the style of a pirate",
+    format_user=StringFormatter(slots=["<|user|>\n{{content}}", {"eos_token"}, "<|assistant|>"]),
+    format_system=StringFormatter(slots=["<|system|>\n{{content}}", {"eos_token"}]),
+    default_system="You are a friendly chatbot who always responds in the style of a pirate",
 )
 
 
 register_template(
     name="ziya",
-    format_user=StringFormatter(container=[{"token": "<human>"}, ":{{content}}\n", {"token": "<bot>"}, ":"]),
-    separator=["\n"],
+    format_user=StringFormatter(slots=[{"token": "<human>"}, ":{{content}}\n", {"token": "<bot>"}, ":"]),
+    format_separator=EmptyFormatter(slots=["\n"]),
 )
diff --git a/src/llmtuner/data/utils.py b/src/llmtuner/data/utils.py
index 53b8054e..b8dfa123 100644
--- a/src/llmtuner/data/utils.py
+++ b/src/llmtuner/data/utils.py
@@ -38,10 +38,10 @@ def checksum(data_files: List[str], file_sha1: Optional[str] = None) -> None:
             logger.warning("Checksum failed: mismatched SHA-1 hash value at {}.".format(data_files[0]))
 
 
-def infer_max_len(source_len: int, target_len: int, data_args: "DataArguments") -> Tuple[int, int]:
-    max_target_len = int(data_args.cutoff_len * (target_len / (source_len + target_len)))
-    max_target_len = max(max_target_len, data_args.reserved_label_len)
-    max_source_len = data_args.cutoff_len - max_target_len
+def infer_max_len(source_len: int, target_len: int, cutoff_len: int, reserved_label_len: int) -> Tuple[int, int]:
+    max_target_len = int(cutoff_len * (target_len / (source_len + target_len)))
+    max_target_len = max(max_target_len, reserved_label_len)
+    max_source_len = cutoff_len - max_target_len
     return max_source_len, max_target_len