ChatOpenAI: bind_tools not callable after with_structured_output

[p3nnst8r]

Checked other resources

• I added a very descriptive title to this issue.
• I searched the LangChain documentation with the integrated search.
• I used the GitHub search to find a similar question and didn't find it.
• I am sure that this is a bug in LangChain rather than my code.
• The bug is not resolved by updating to the latest stable version of LangChain (or the specific integration package).

Example Code

from langchain_openai import ChatOpenAI
from pydantic import BaseModel, Field
from langchain.tools import StructuredTool

class ResponseModel(BaseModel):
  a_value:str = Field(description="This doesn't matter much")

def a_func(val: int):
    return True

a_tool = StructuredTool.from_function(
            func=a_func,
            name="A func",
            description="A function you will need",
        )

llm = ChatOpenAI(model="gpt-4o-mini",temperature=0)
structured_llm = llm.with_structured_output(ResponseModel)
llm_with_tools = structured_llm.bind_tools([a_tool]) <----- not available

Error Message and Stack Trace (if applicable)

'RunnableSequence' object has no attribute 'bind_tools'

Description

I am attempting to retrieved structured output in a json format (to pass via an api to a frontend), and I also require calling out to tools. I cannot figure out how to combine the two, or there is an issue with code to do so.

System Info

System Information

OS: Darwin
OS Version: Darwin Kernel Version 24.1.0: Thu Oct 10 21:02:27 PDT 2024; root:xnu-11215.41.3~2/RELEASE_X86_64
Python Version: 3.13.1 (main, Dec 3 2024, 17:59:52) [Clang 16.0.0 (clang-1600.0.26.4)]

Package Information

langchain_core: 0.3.28
langchain: 0.3.13
langchain_community: 0.3.13
langsmith: 0.2.4
langchain_experimental: 0.3.4
langchain_openai: 0.2.14
langchain_text_splitters: 0.3.4

Optional packages not installed

langserve

Other Dependencies

aiohttp: 3.10.10
async-timeout: Installed. No version info available.
dataclasses-json: 0.6.7
httpx: 0.27.2
httpx-sse: 0.4.0
jsonpatch: 1.33
langsmith-pyo3: Installed. No version info available.
numpy: 1.26.4
openai: 1.58.1
orjson: 3.10.9
packaging: 24.1
pydantic: 2.9.2
pydantic-settings: 2.6.0
PyYAML: 6.0.2
requests: 2.32.3
requests-toolbelt: 1.0.0
SQLAlchemy: 2.0.36
tenacity: 9.0.0
tiktoken: 0.8.0
typing-extensions: 4.12.2

[keenborder786]

@p3nnst8r I don't know what you are trying to achieve, but essentially, with_structured_output returns a RunnableSequence that consists of the following two Runnables:
RunnableBinding (where ChatOpenAI is binding, and the given schema is passed as an additional parameter to tools) -> OutputParser.

So, calling bind_tools again on the RunnableSequence is causing this error.

This is not recommended, but if you want to use additional tools in the same RunnableSequence, you can do the following:

structured_llm.steps[0] = structured_llm.steps[0].bound.bind_tools([a_tool, ResponseModel])

However, I still don't understand why you want to use additional tools when with_structured_output is only used to make the LLM parse the result into a specific format. It is recommended that you initiate a different instance of the LLM with the desired tools.