Add support for custom LLM implementations (#2277)

* Add support for custom LLM implementations

Co-Authored-By: Joe Moura <joao@crewai.com>

* Fix import sorting and type annotations

Co-Authored-By: Joe Moura <joao@crewai.com>

* Fix linting issues with import sorting

Co-Authored-By: Joe Moura <joao@crewai.com>

* Fix type errors in crew.py by updating tool-related methods to return List[BaseTool]

Co-Authored-By: Joe Moura <joao@crewai.com>

* Enhance custom LLM implementation with better error handling, documentation, and test coverage

Co-Authored-By: Joe Moura <joao@crewai.com>

* Refactor LLM module by extracting BaseLLM to a separate file

This commit moves the BaseLLM abstract base class from llm.py to a new file llms/base_llm.py to improve code organization. The changes include:

- Creating a new file src/crewai/llms/base_llm.py
- Moving the BaseLLM class to the new file
- Updating imports in __init__.py and llm.py to reflect the new location
- Updating test cases to use the new import path

The refactoring maintains the existing functionality while improving the project's module structure.

* Add AISuite LLM support and update dependencies

- Integrate AISuite as a new third-party LLM option
- Update pyproject.toml and uv.lock to include aisuite package
- Modify BaseLLM to support more flexible initialization
- Remove unnecessary LLM imports across multiple files
- Implement AISuiteLLM with basic chat completion functionality

* Update AISuiteLLM and LLM utility type handling

- Modify AISuiteLLM to support more flexible input types for messages
- Update type hints in AISuiteLLM to allow string or list of message dictionaries
- Enhance LLM utility function to support broader LLM type annotations
- Remove default `self.stop` attribute from BaseLLM initialization

* 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

* Improve stop words handling in CrewAgentExecutor

- Add support for handling existing stop words in LLM configuration
- Ensure stop words are correctly merged and deduplicated
- Update type hints to support both LLM and BaseLLM types

* Remove abstract method set_callbacks from BaseLLM class

* Enhance CustomLLM and JWTAuthLLM initialization with model parameter

- Update CustomLLM to accept a model parameter during initialization
- Modify test cases to include the new model argument
- Ensure JWTAuthLLM and TimeoutHandlingLLM also utilize the model parameter in their constructors
- Update type hints in create_llm function to support both LLM and BaseLLM types

* Enhance create_llm function to support BaseLLM type

- Update the create_llm function to accept both LLM and BaseLLM instances
- Ensure compatibility with existing LLM handling logic

* Update type hint for initialize_chat_llm to support BaseLLM

- Modify the return type of initialize_chat_llm function to allow for both LLM and BaseLLM instances
- Ensure compatibility with recent changes in create_llm function

* Refactor AISuiteLLM to include tools parameter in completion methods

- Update the _prepare_completion_params method to accept an optional tools parameter
- Modify the chat completion method to utilize the new tools parameter for enhanced functionality
- Clean up print statements for better code clarity

* Remove unused tool_calls handling in AISuiteLLM chat completion method for cleaner code.

* Refactor Crew class and LLM hierarchy for improved type handling and code clarity

- Update Crew class methods to enhance readability with consistent formatting and type hints.
- Change LLM class to inherit from BaseLLM for better structure.
- Remove unnecessary type checks and streamline tool handling in CrewAgentExecutor.
- Adjust BaseLLM to provide default implementations for stop words and context window size methods.
- Clean up AISuiteLLM by removing unused methods related to stop words and context window size.

* Remove unused `stream` method from `BaseLLM` class to enhance code clarity and maintainability.

---------

Co-authored-by: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
Co-authored-by: Joe Moura <joao@crewai.com>
Co-authored-by: Lorenze Jay <lorenzejaytech@gmail.com>
Co-authored-by: João Moura <joaomdmoura@gmail.com>
Co-authored-by: Brandon Hancock (bhancock_ai) <109994880+bhancockio@users.noreply.github.com>
This commit is contained in:
devin-ai-integration[bot]
2025-03-25 12:39:08 -04:00
committed by GitHub
parent 3dea3d0183
commit 807c13e144
16 changed files with 1671 additions and 61 deletions

View File

@@ -5,6 +5,7 @@ from crewai.crew import Crew
from crewai.flow.flow import Flow
from crewai.knowledge.knowledge import Knowledge
from crewai.llm import LLM
from crewai.llms.base_llm import BaseLLM
from crewai.process import Process
from crewai.task import Task
@@ -21,6 +22,7 @@ __all__ = [
"Process",
"Task",
"LLM",
"BaseLLM",
"Flow",
"Knowledge",
]

View File

@@ -11,7 +11,7 @@ from crewai.agents.crew_agent_executor import CrewAgentExecutor
from crewai.knowledge.knowledge import Knowledge
from crewai.knowledge.source.base_knowledge_source import BaseKnowledgeSource
from crewai.knowledge.utils.knowledge_utils import extract_knowledge_context
from crewai.llm import LLM
from crewai.llm import BaseLLM
from crewai.memory.contextual.contextual_memory import ContextualMemory
from crewai.security import Fingerprint
from crewai.task import Task
@@ -71,10 +71,10 @@ class Agent(BaseAgent):
default=True,
description="Use system prompt for the agent.",
)
llm: Union[str, InstanceOf[LLM], Any] = Field(
llm: Union[str, InstanceOf[BaseLLM], Any] = Field(
description="Language model that will run the agent.", default=None
)
function_calling_llm: Optional[Union[str, InstanceOf[LLM], Any]] = Field(
function_calling_llm: Optional[Union[str, InstanceOf[BaseLLM], Any]] = Field(
description="Language model that will run the agent.", default=None
)
system_template: Optional[str] = Field(
@@ -118,7 +118,9 @@ class Agent(BaseAgent):
self.agent_ops_agent_name = self.role
self.llm = create_llm(self.llm)
if self.function_calling_llm and not isinstance(self.function_calling_llm, LLM):
if self.function_calling_llm and not isinstance(
self.function_calling_llm, BaseLLM
):
self.function_calling_llm = create_llm(self.function_calling_llm)
if not self.agent_executor:

View File

@@ -13,7 +13,7 @@ from crewai.agents.parser import (
OutputParserException,
)
from crewai.agents.tools_handler import ToolsHandler
from crewai.llm import LLM
from crewai.llm import BaseLLM
from crewai.tools.base_tool import BaseTool
from crewai.tools.tool_usage import ToolUsage, ToolUsageErrorException
from crewai.utilities import I18N, Printer
@@ -61,7 +61,7 @@ class CrewAgentExecutor(CrewAgentExecutorMixin):
callbacks: List[Any] = [],
):
self._i18n: I18N = I18N()
self.llm: LLM = llm
self.llm: BaseLLM = llm
self.task = task
self.agent = agent
self.crew = crew
@@ -87,8 +87,14 @@ class CrewAgentExecutor(CrewAgentExecutorMixin):
self.tool_name_to_tool_map: Dict[str, BaseTool] = {
tool.name: tool for tool in self.tools
}
self.stop = stop_words
self.llm.stop = list(set(self.llm.stop + self.stop))
existing_stop = self.llm.stop or []
self.llm.stop = list(
set(
existing_stop + self.stop
if isinstance(existing_stop, list)
else self.stop
)
)
def invoke(self, inputs: Dict[str, str]) -> Dict[str, Any]:
if "system" in self.prompt:

View File

@@ -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 LLM
from crewai.llm import LLM, BaseLLM
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[LLM]:
def initialize_chat_llm(crew: Crew) -> Optional[LLM | BaseLLM]:
"""Initializes the chat LLM and handles exceptions."""
try:
return create_llm(crew.chat_llm)

View File

@@ -6,8 +6,9 @@ import warnings
from concurrent.futures import Future
from copy import copy as shallow_copy
from hashlib import md5
from typing import Any, Callable, Dict, List, Optional, Set, Tuple, Union
from typing import Any, Callable, Dict, List, Optional, Set, Tuple, TypeVar, Union, cast
from langchain_core.tools import BaseTool as LangchainBaseTool
from pydantic import (
UUID4,
BaseModel,
@@ -26,7 +27,7 @@ from crewai.agents.cache import CacheHandler
from crewai.crews.crew_output import CrewOutput
from crewai.knowledge.knowledge import Knowledge
from crewai.knowledge.source.base_knowledge_source import BaseKnowledgeSource
from crewai.llm import LLM
from crewai.llm import LLM, BaseLLM
from crewai.memory.entity.entity_memory import EntityMemory
from crewai.memory.long_term.long_term_memory import LongTermMemory
from crewai.memory.short_term.short_term_memory import ShortTermMemory
@@ -37,7 +38,7 @@ from crewai.task import Task
from crewai.tasks.conditional_task import ConditionalTask
from crewai.tasks.task_output import TaskOutput
from crewai.tools.agent_tools.agent_tools import AgentTools
from crewai.tools.base_tool import Tool
from crewai.tools.base_tool import BaseTool, Tool
from crewai.types.usage_metrics import UsageMetrics
from crewai.utilities import I18N, FileHandler, Logger, RPMController
from crewai.utilities.constants import TRAINING_DATA_FILE
@@ -153,7 +154,7 @@ class Crew(BaseModel):
default=None,
description="Metrics for the LLM usage during all tasks execution.",
)
manager_llm: Optional[Any] = Field(
manager_llm: Optional[Union[str, InstanceOf[BaseLLM], Any]] = Field(
description="Language model that will run the agent.", default=None
)
manager_agent: Optional[BaseAgent] = Field(
@@ -187,7 +188,7 @@ class Crew(BaseModel):
default=None,
description="Maximum number of requests per minute for the crew execution to be respected.",
)
prompt_file: str = Field(
prompt_file: Optional[str] = Field(
default=None,
description="Path to the prompt json file to be used for the crew.",
)
@@ -199,7 +200,7 @@ class Crew(BaseModel):
default=False,
description="Plan the crew execution and add the plan to the crew.",
)
planning_llm: Optional[Any] = Field(
planning_llm: Optional[Union[str, InstanceOf[BaseLLM], Any]] = Field(
default=None,
description="Language model that will run the AgentPlanner if planning is True.",
)
@@ -215,7 +216,7 @@ class Crew(BaseModel):
default=None,
description="Knowledge sources for the crew. Add knowledge sources to the knowledge object.",
)
chat_llm: Optional[Any] = Field(
chat_llm: Optional[Union[str, InstanceOf[BaseLLM], Any]] = Field(
default=None,
description="LLM used to handle chatting with the crew.",
)
@@ -819,7 +820,12 @@ class Crew(BaseModel):
# Determine which tools to use - task tools take precedence over agent tools
tools_for_task = task.tools or agent_to_use.tools or []
tools_for_task = self._prepare_tools(agent_to_use, task, tools_for_task)
# Prepare tools and ensure they're compatible with task execution
tools_for_task = self._prepare_tools(
agent_to_use,
task,
cast(Union[List[Tool], List[BaseTool]], tools_for_task),
)
self._log_task_start(task, agent_to_use.role)
@@ -838,7 +844,7 @@ class Crew(BaseModel):
future = task.execute_async(
agent=agent_to_use,
context=context,
tools=tools_for_task,
tools=cast(List[BaseTool], tools_for_task),
)
futures.append((task, future, task_index))
else:
@@ -850,7 +856,7 @@ class Crew(BaseModel):
task_output = task.execute_sync(
agent=agent_to_use,
context=context,
tools=tools_for_task,
tools=cast(List[BaseTool], tools_for_task),
)
task_outputs.append(task_output)
self._process_task_result(task, task_output)
@@ -888,10 +894,12 @@ class Crew(BaseModel):
return None
def _prepare_tools(
self, agent: BaseAgent, task: Task, tools: List[Tool]
) -> List[Tool]:
self, agent: BaseAgent, task: Task, tools: Union[List[Tool], List[BaseTool]]
) -> List[BaseTool]:
# Add delegation tools if agent allows delegation
if agent.allow_delegation:
if hasattr(agent, "allow_delegation") and getattr(
agent, "allow_delegation", False
):
if self.process == Process.hierarchical:
if self.manager_agent:
tools = self._update_manager_tools(task, tools)
@@ -900,17 +908,24 @@ class Crew(BaseModel):
"Manager agent is required for hierarchical process."
)
elif agent and agent.allow_delegation:
elif agent:
tools = self._add_delegation_tools(task, tools)
# Add code execution tools if agent allows code execution
if agent.allow_code_execution:
if hasattr(agent, "allow_code_execution") and getattr(
agent, "allow_code_execution", False
):
tools = self._add_code_execution_tools(agent, tools)
if agent and agent.multimodal:
if (
agent
and hasattr(agent, "multimodal")
and getattr(agent, "multimodal", False)
):
tools = self._add_multimodal_tools(agent, tools)
return tools
# Return a List[BaseTool] which is compatible with both Task.execute_sync and Task.execute_async
return cast(List[BaseTool], tools)
def _get_agent_to_use(self, task: Task) -> Optional[BaseAgent]:
if self.process == Process.hierarchical:
@@ -918,11 +933,13 @@ class Crew(BaseModel):
return task.agent
def _merge_tools(
self, existing_tools: List[Tool], new_tools: List[Tool]
) -> List[Tool]:
self,
existing_tools: Union[List[Tool], List[BaseTool]],
new_tools: Union[List[Tool], List[BaseTool]],
) -> List[BaseTool]:
"""Merge new tools into existing tools list, avoiding duplicates by tool name."""
if not new_tools:
return existing_tools
return cast(List[BaseTool], existing_tools)
# Create mapping of tool names to new tools
new_tool_map = {tool.name: tool for tool in new_tools}
@@ -933,23 +950,41 @@ class Crew(BaseModel):
# Add all new tools
tools.extend(new_tools)
return tools
return cast(List[BaseTool], tools)
def _inject_delegation_tools(
self, tools: List[Tool], task_agent: BaseAgent, agents: List[BaseAgent]
):
delegation_tools = task_agent.get_delegation_tools(agents)
return self._merge_tools(tools, delegation_tools)
self,
tools: Union[List[Tool], List[BaseTool]],
task_agent: BaseAgent,
agents: List[BaseAgent],
) -> List[BaseTool]:
if hasattr(task_agent, "get_delegation_tools"):
delegation_tools = task_agent.get_delegation_tools(agents)
# Cast delegation_tools to the expected type for _merge_tools
return self._merge_tools(tools, cast(List[BaseTool], delegation_tools))
return cast(List[BaseTool], tools)
def _add_multimodal_tools(self, agent: BaseAgent, tools: List[Tool]):
multimodal_tools = agent.get_multimodal_tools()
return self._merge_tools(tools, multimodal_tools)
def _add_multimodal_tools(
self, agent: BaseAgent, tools: Union[List[Tool], List[BaseTool]]
) -> List[BaseTool]:
if hasattr(agent, "get_multimodal_tools"):
multimodal_tools = agent.get_multimodal_tools()
# Cast multimodal_tools to the expected type for _merge_tools
return self._merge_tools(tools, cast(List[BaseTool], multimodal_tools))
return cast(List[BaseTool], tools)
def _add_code_execution_tools(self, agent: BaseAgent, tools: List[Tool]):
code_tools = agent.get_code_execution_tools()
return self._merge_tools(tools, code_tools)
def _add_code_execution_tools(
self, agent: BaseAgent, tools: Union[List[Tool], List[BaseTool]]
) -> List[BaseTool]:
if hasattr(agent, "get_code_execution_tools"):
code_tools = agent.get_code_execution_tools()
# Cast code_tools to the expected type for _merge_tools
return self._merge_tools(tools, cast(List[BaseTool], code_tools))
return cast(List[BaseTool], tools)
def _add_delegation_tools(self, task: Task, tools: List[Tool]):
def _add_delegation_tools(
self, task: Task, tools: Union[List[Tool], List[BaseTool]]
) -> List[BaseTool]:
agents_for_delegation = [agent for agent in self.agents if agent != task.agent]
if len(self.agents) > 1 and len(agents_for_delegation) > 0 and task.agent:
if not tools:
@@ -957,7 +992,7 @@ class Crew(BaseModel):
tools = self._inject_delegation_tools(
tools, task.agent, agents_for_delegation
)
return tools
return cast(List[BaseTool], tools)
def _log_task_start(self, task: Task, role: str = "None"):
if self.output_log_file:
@@ -965,7 +1000,9 @@ class Crew(BaseModel):
task_name=task.name, task=task.description, agent=role, status="started"
)
def _update_manager_tools(self, task: Task, tools: List[Tool]):
def _update_manager_tools(
self, task: Task, tools: Union[List[Tool], List[BaseTool]]
) -> List[BaseTool]:
if self.manager_agent:
if task.agent:
tools = self._inject_delegation_tools(tools, task.agent, [task.agent])
@@ -973,7 +1010,7 @@ class Crew(BaseModel):
tools = self._inject_delegation_tools(
tools, self.manager_agent, self.agents
)
return tools
return cast(List[BaseTool], tools)
def _get_context(self, task: Task, task_outputs: List[TaskOutput]):
context = (
@@ -1214,13 +1251,14 @@ class Crew(BaseModel):
def test(
self,
n_iterations: int,
eval_llm: Union[str, InstanceOf[LLM]],
eval_llm: Union[str, InstanceOf[BaseLLM]],
inputs: Optional[Dict[str, Any]] = None,
) -> None:
"""Test and evaluate the Crew with the given inputs for n iterations concurrently using concurrent.futures."""
try:
eval_llm = create_llm(eval_llm)
if not eval_llm:
# Create LLM instance and ensure it's of type LLM for CrewEvaluator
llm_instance = create_llm(eval_llm)
if not llm_instance:
raise ValueError("Failed to create LLM instance.")
crewai_event_bus.emit(
@@ -1228,12 +1266,12 @@ class Crew(BaseModel):
CrewTestStartedEvent(
crew_name=self.name or "crew",
n_iterations=n_iterations,
eval_llm=eval_llm,
eval_llm=llm_instance,
inputs=inputs,
),
)
test_crew = self.copy()
evaluator = CrewEvaluator(test_crew, eval_llm) # type: ignore[arg-type]
evaluator = CrewEvaluator(test_crew, llm_instance)
for i in range(1, n_iterations + 1):
evaluator.set_iteration(i)

View File

@@ -40,6 +40,7 @@ with warnings.catch_warnings():
from litellm.utils import supports_response_schema
from crewai.llms.base_llm import BaseLLM
from crewai.utilities.events import crewai_event_bus
from crewai.utilities.exceptions.context_window_exceeding_exception import (
LLMContextLengthExceededException,
@@ -218,7 +219,7 @@ class StreamingChoices(TypedDict):
finish_reason: Optional[str]
class LLM:
class LLM(BaseLLM):
def __init__(
self,
model: str,

View File

@@ -0,0 +1,91 @@
from abc import ABC, abstractmethod
from typing import Any, Callable, Dict, List, Optional, Union
class BaseLLM(ABC):
"""Abstract base class for LLM implementations.
This class defines the interface that all LLM implementations must follow.
Users can extend this class to create custom LLM implementations that don't
rely on litellm's authentication mechanism.
Custom LLM implementations should handle error cases gracefully, including
timeouts, authentication failures, and malformed responses. They should also
implement proper validation for input parameters and provide clear error
messages when things go wrong.
Attributes:
stop (list): A list of stop sequences that the LLM should use to stop generation.
This is used by the CrewAgentExecutor and other components.
"""
model: str
temperature: Optional[float] = None
stop: Optional[List[str]] = None
def __init__(
self,
model: str,
temperature: Optional[float] = None,
):
"""Initialize the BaseLLM with default attributes.
This constructor sets default values for attributes that are expected
by the CrewAgentExecutor and other components.
All custom LLM implementations should call super().__init__() to ensure
that these default attributes are properly initialized.
"""
self.model = model
self.temperature = temperature
self.stop = []
@abstractmethod
def call(
self,
messages: Union[str, List[Dict[str, str]]],
tools: Optional[List[dict]] = None,
callbacks: Optional[List[Any]] = None,
available_functions: Optional[Dict[str, Any]] = None,
) -> Union[str, Any]:
"""Call the LLM with the given messages.
Args:
messages: Input messages for the LLM.
Can be a string or list of message dictionaries.
If string, it will be converted to a single user message.
If list, each dict must have 'role' and 'content' keys.
tools: Optional list of tool schemas for function calling.
Each tool should define its name, description, and parameters.
callbacks: Optional list of callback functions to be executed
during and after the LLM call.
available_functions: Optional dict mapping function names to callables
that can be invoked by the LLM.
Returns:
Either a text response from the LLM (str) or
the result of a tool function call (Any).
Raises:
ValueError: If the messages format is invalid.
TimeoutError: If the LLM request times out.
RuntimeError: If the LLM request fails for other reasons.
"""
pass
def supports_stop_words(self) -> bool:
"""Check if the LLM supports stop words.
Returns:
bool: True if the LLM supports stop words, False otherwise.
"""
return True # Default implementation assumes support for stop words
def get_context_window_size(self) -> int:
"""Get the context window size for the LLM.
Returns:
int: The number of tokens/characters the model can handle.
"""
# Default implementation - subclasses should override with model-specific values
return 4096

38
src/crewai/llms/third_party/ai_suite.py vendored Normal file
View File

@@ -0,0 +1,38 @@
from typing import Any, Dict, List, Optional, Union
import aisuite as ai
from crewai.llms.base_llm import BaseLLM
class AISuiteLLM(BaseLLM):
def __init__(self, model: str, temperature: Optional[float] = None, **kwargs):
super().__init__(model, temperature, **kwargs)
self.client = ai.Client()
def call(
self,
messages: Union[str, List[Dict[str, str]]],
tools: Optional[List[dict]] = None,
callbacks: Optional[List[Any]] = None,
available_functions: Optional[Dict[str, Any]] = None,
) -> Union[str, Any]:
completion_params = self._prepare_completion_params(messages, tools)
response = self.client.chat.completions.create(**completion_params)
return response.choices[0].message.content
def _prepare_completion_params(
self,
messages: Union[str, List[Dict[str, str]]],
tools: Optional[List[dict]] = None,
) -> Dict[str, Any]:
return {
"model": self.model,
"messages": messages,
"temperature": self.temperature,
"tools": tools,
}
def supports_function_calling(self) -> bool:
return False

View File

@@ -6,7 +6,7 @@ from rich.console import Console
from rich.table import Table
from crewai.agent import Agent
from crewai.llm import LLM
from crewai.llm import BaseLLM
from crewai.task import Task
from crewai.tasks.task_output import TaskOutput
from crewai.telemetry import Telemetry
@@ -24,7 +24,7 @@ class CrewEvaluator:
Attributes:
crew (Crew): The crew of agents to evaluate.
eval_llm (LLM): Language model instance to use for evaluations
eval_llm (BaseLLM): Language model instance to use for evaluations
tasks_scores (defaultdict): A dictionary to store the scores of the agents for each task.
iteration (int): The current iteration of the evaluation.
"""
@@ -33,7 +33,7 @@ class CrewEvaluator:
run_execution_times: defaultdict = defaultdict(list)
iteration: int = 0
def __init__(self, crew, eval_llm: InstanceOf[LLM]):
def __init__(self, crew, eval_llm: InstanceOf[BaseLLM]):
self.crew = crew
self.llm = eval_llm
self._telemetry = Telemetry()

View File

@@ -2,28 +2,28 @@ import os
from typing import Any, Dict, List, Optional, Union
from crewai.cli.constants import DEFAULT_LLM_MODEL, ENV_VARS, LITELLM_PARAMS
from crewai.llm import LLM
from crewai.llm import LLM, BaseLLM
def create_llm(
llm_value: Union[str, LLM, Any, None] = None,
) -> Optional[LLM]:
) -> Optional[LLM | BaseLLM]:
"""
Creates or returns an LLM instance based on the given llm_value.
Args:
llm_value (str | LLM | Any | None):
llm_value (str | BaseLLM | Any | None):
- str: The model name (e.g., "gpt-4").
- LLM: Already instantiated LLM, returned as-is.
- BaseLLM: Already instantiated BaseLLM (including LLM), returned as-is.
- Any: Attempt to extract known attributes like model_name, temperature, etc.
- None: Use environment-based or fallback default model.
Returns:
An LLM instance if successful, or None if something fails.
A BaseLLM instance if successful, or None if something fails.
"""
# 1) If llm_value is already an LLM object, return it directly
if isinstance(llm_value, LLM):
# 1) If llm_value is already a BaseLLM or LLM object, return it directly
if isinstance(llm_value, LLM) or isinstance(llm_value, BaseLLM):
return llm_value
# 2) If llm_value is a string (model name)