How to convert tools to OpenAI Functions

This notebook goes over how to use LangChain tools as OpenAI functions.

%pip install -qU langchain-community langchain-openai

from langchain_community.tools import MoveFileTool
from langchain_core.messages import HumanMessage
from langchain_core.utils.function_calling import convert_to_openai_function
from langchain_openai import ChatOpenAI

API Reference:MoveFileTool | HumanMessage | convert_to_openai_function | ChatOpenAI

model = ChatOpenAI(model="gpt-3.5-turbo")

tools = [MoveFileTool()]
functions = [convert_to_openai_function(t) for t in tools]

functions[0]

{'name': 'move_file',
 'description': 'Move or rename a file from one location to another',
 'parameters': {'type': 'object',
  'properties': {'source_path': {'description': 'Path of the file to move',
    'type': 'string'},
   'destination_path': {'description': 'New path for the moved file',
    'type': 'string'}},
  'required': ['source_path', 'destination_path']}}

message = model.invoke(
    [HumanMessage(content="move file foo to bar")], functions=functions
)

message

AIMessage(content='', additional_kwargs={'function_call': {'arguments': '{\n  "source_path": "foo",\n  "destination_path": "bar"\n}', 'name': 'move_file'}})

message.additional_kwargs["function_call"]

{'name': 'move_file',
 'arguments': '{\n  "source_path": "foo",\n  "destination_path": "bar"\n}'}

With OpenAI chat models we can also automatically bind and convert function-like objects with bind_functions

model_with_functions = model.bind_functions(tools)
model_with_functions.invoke([HumanMessage(content="move file foo to bar")])

AIMessage(content='', additional_kwargs={'function_call': {'arguments': '{\n  "source_path": "foo",\n  "destination_path": "bar"\n}', 'name': 'move_file'}})

Or we can use the update OpenAI API that uses tools and tool_choice instead of functions and function_call by using ChatOpenAI.bind_tools:

model_with_tools = model.bind_tools(tools)
model_with_tools.invoke([HumanMessage(content="move file foo to bar")])

AIMessage(content='', additional_kwargs={'tool_calls': [{'id': 'call_btkY3xV71cEVAOHnNa5qwo44', 'function': {'arguments': '{\n  "source_path": "foo",\n  "destination_path": "bar"\n}', 'name': 'move_file'}, 'type': 'function'}]})