Update LLM imports and type hints across multiple files

- Modify imports in crew_chat.py to use LLM instead of BaseLLM
- Update type hints in llm_utils.py to use LLM type
- Add optional `stop` parameter to BaseLLM initialization
- Refactor type handling for LLM creation and usage

src/crewai/cli/crew_chat.py

@@ -14,7 +14,7 @@ from packaging import version
 from crewai.cli.utils import read_toml
 from crewai.cli.version import get_crewai_version
 from crewai.crew import Crew
-from crewai.llm import BaseLLM
+from crewai.llm import LLM
 from crewai.types.crew_chat import ChatInputField, ChatInputs
 from crewai.utilities.llm_utils import create_llm
 
@@ -116,7 +116,7 @@ def show_loading(event: threading.Event):
     print()
 
 
-def initialize_chat_llm(crew: Crew) -> Optional[BaseLLM]:
+def initialize_chat_llm(crew: Crew) -> Optional[LLM]:
     """Initializes the chat LLM and handles exceptions."""
     try:
         return create_llm(crew.chat_llm)
@@ -220,7 +220,7 @@ def get_user_input() -> str:
 
 def handle_user_input(
     user_input: str,
-    chat_llm: BaseLLM,
+    chat_llm: LLM,
     messages: List[Dict[str, str]],
     crew_tool_schema: Dict[str, Any],
     available_functions: Dict[str, Any],

src/crewai/llms/base_llm.py

@@ -21,8 +21,14 @@ class BaseLLM(ABC):
 
     model: str
     temperature: Optional[float] = None
+    stop: Optional[Union[str, List[str]]] = None
 
-    def __init__(self, model: str, temperature: Optional[float] = None):
+    def __init__(
+        self,
+        model: str,
+        temperature: Optional[float] = None,
+        stop: Optional[Union[str, List[str]]] = None,
+    ):
         """Initialize the BaseLLM with default attributes.
 
         This constructor sets default values for attributes that are expected
@@ -33,6 +39,7 @@ class BaseLLM(ABC):
         """
         self.model = model
         self.temperature = temperature
+        self.stop = stop
 
     @abstractmethod
     def call(

src/crewai/utilities/llm_utils.py

@@ -6,8 +6,8 @@ from crewai.llm import LLM, BaseLLM
 
 
 def create_llm(
-    llm_value: Union[str, BaseLLM, LLM, Any, None] = None,
-) -> Optional[BaseLLM | LLM]:
+    llm_value: Union[str, LLM, Any, None] = None,
+) -> Optional[LLM]:
     """
     Creates or returns an LLM instance based on the given llm_value.
 
@@ -23,7 +23,7 @@ def create_llm(
     """
 
     # 1) If llm_value is already a BaseLLM object, return it directly
-    if isinstance(llm_value, BaseLLM):
+    if isinstance(llm_value, LLM):
         return llm_value
 
     # 2) If llm_value is a string (model name)