[Google Generative AI] Structured Output doesn't work with advanced schema

[ToyHugs]

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

Collab link : https://colab.research.google.com/drive/1BCat5tBZRcxUhjQ3vGJD3Zu1eiqYIAWz?usp=sharing
Code :

!pip install -qU langchain langchain-community langchain-core
!pip install -qU langchain-google-genai
!pip install -qU langchain-text-splitters tiktoken
!pip install -qU faiss-gpu

import os
import getpass

os.environ["GOOGLE_API_KEY"] = getpass.getpass("Google API Key:")

import re

import requests
from langchain_community.document_loaders import BSHTMLLoader

# Download the content
response = requests.get("https://en.wikipedia.org/wiki/Car")
# Write it to a file
with open("car.html", "w", encoding="utf-8") as f:
    f.write(response.text)
# Load it with an HTML parser
loader = BSHTMLLoader("car.html")
document = loader.load()[0]
# Clean up code
# Replace consecutive new lines with a single new line
document.page_content = re.sub("\n\n+", "\n", document.page_content)

from typing import List, Optional

from langchain_core.prompts import ChatPromptTemplate, MessagesPlaceholder
from langchain_core.pydantic_v1 import BaseModel, Field


class KeyDevelopment(BaseModel):
    """Information about a development in the history of cars."""

    year: int = Field(
        ..., description="The year when there was an important historic development."
    )
    description: str = Field(
        ..., description="What happened in this year? What was the development?"
    )
    evidence: str = Field(
        ...,
        description="Repeat in verbatim the sentence(s) from which the year and description information were extracted",
    )


class ExtractionData(BaseModel):
    """Extracted information about key developments in the history of cars."""

    key_developments: List[KeyDevelopment]


# Define a custom prompt to provide instructions and any additional context.
# 1) You can add examples into the prompt template to improve extraction quality
# 2) Introduce additional parameters to take context into account (e.g., include metadata
#    about the document from which the text was extracted.)
prompt = ChatPromptTemplate.from_messages(
    [
        (
            "system",
            "You are an expert at identifying key historic development in text. "
            "Only extract important historic developments. Extract nothing if no important information can be found in the text.",
        ),
        ("human", "{text}"),
    ]
)

from langchain_google_genai import ChatGoogleGenerativeAI

llm = ChatGoogleGenerativeAI(model="gemini-pro")

extractor = prompt | llm.with_structured_output(
    schema=ExtractionData,
    include_raw=False,
)

from langchain_text_splitters import TokenTextSplitter

text_splitter = TokenTextSplitter(
    # Controls the size of each chunk
    chunk_size=2000,
    # Controls overlap between chunks
    chunk_overlap=20,
)

texts = text_splitter.split_text(document.page_content)

from langchain_community.vectorstores import FAISS
from langchain_core.documents import Document
from langchain_core.runnables import RunnableLambda
from langchain_google_genai import GoogleGenerativeAIEmbeddings
from langchain_text_splitters import CharacterTextSplitter

texts = text_splitter.split_text(document.page_content)
vectorstore = FAISS.from_texts(texts, embedding=GoogleGenerativeAIEmbeddings(model="models/embedding-001"))

retriever = vectorstore.as_retriever(
    search_kwargs={"k": 1}
)  # Only extract from first document

rag_extractor = {
    "text": retriever | (lambda docs: docs[0].page_content)  # fetch content of top doc
} | extractor

results = rag_extractor.invoke("Key developments associated with cars")

Error Message and Stack Trace (if applicable)

InvalidArgument Traceback (most recent call last)
/usr/local/lib/python3.10/dist-packages/langchain_google_genai/chat_models.py in _chat_with_retry(**kwargs)
177 try:
--> 178 return generation_method(**kwargs)
179 # Do not retry for these errors.

25 frames
/usr/local/lib/python3.10/dist-packages/google/ai/generativelanguage_v1beta/services/generative_service/client.py in generate_content(self, request, model, contents, retry, timeout, metadata)
826 # Send the request.
--> 827 response = rpc(
828 request,

/usr/local/lib/python3.10/dist-packages/google/api_core/gapic_v1/method.py in call(self, timeout, retry, compression, *args, **kwargs)
130
--> 131 return wrapped_func(*args, **kwargs)
132

/usr/local/lib/python3.10/dist-packages/google/api_core/retry/retry_unary.py in retry_wrapped_func(*args, **kwargs)
292 )
--> 293 return retry_target(
294 target,

/usr/local/lib/python3.10/dist-packages/google/api_core/retry/retry_unary.py in retry_target(target, predicate, sleep_generator, timeout, on_error, exception_factory, **kwargs)
152 # defer to shared logic for handling errors
--> 153 _retry_error_helper(
154 exc,

/usr/local/lib/python3.10/dist-packages/google/api_core/retry/retry_base.py in _retry_error_helper(exc, deadline, next_sleep, error_list, predicate_fn, on_error_fn, exc_factory_fn, original_timeout)
211 )
--> 212 raise final_exc from source_exc
213 if on_error_fn is not None:

/usr/local/lib/python3.10/dist-packages/google/api_core/retry/retry_unary.py in retry_target(target, predicate, sleep_generator, timeout, on_error, exception_factory, **kwargs)
143 try:
--> 144 result = target()
145 if inspect.isawaitable(result):

/usr/local/lib/python3.10/dist-packages/google/api_core/timeout.py in func_with_timeout(*args, **kwargs)
119
--> 120 return func(*args, **kwargs)
121

/usr/local/lib/python3.10/dist-packages/google/api_core/grpc_helpers.py in error_remapped_callable(*args, **kwargs)
80 except grpc.RpcError as exc:
---> 81 raise exceptions.from_grpc_error(exc) from exc
82

InvalidArgument: 400 * GenerateContentRequest.tools[0].function_declarations[0].parameters.properties[key_developments].items: missing field.

The above exception was the direct cause of the following exception:

ChatGoogleGenerativeAIError Traceback (most recent call last)
in <cell line: 1>()
----> 1 results = rag_extractor.invoke("Key developments associated with cars")

/usr/local/lib/python3.10/dist-packages/langchain_core/runnables/base.py in invoke(self, input, config, **kwargs)
2794 input = step.invoke(input, config, **kwargs)
2795 else:
-> 2796 input = step.invoke(input, config)
2797 # finish the root run
2798 except BaseException as e:

/usr/local/lib/python3.10/dist-packages/langchain_core/runnables/base.py in invoke(self, input, config, **kwargs)
4976 **kwargs: Optional[Any],
4977 ) -> Output:
-> 4978 return self.bound.invoke(
4979 input,
4980 self._merge_configs(config),

/usr/local/lib/python3.10/dist-packages/langchain_core/language_models/chat_models.py in invoke(self, input, config, stop, **kwargs)
263 return cast(
264 ChatGeneration,
--> 265 self.generate_prompt(
266 [self._convert_input(input)],
267 stop=stop,

/usr/local/lib/python3.10/dist-packages/langchain_core/language_models/chat_models.py in generate_prompt(self, prompts, stop, callbacks, **kwargs)
696 ) -> LLMResult:
697 prompt_messages = [p.to_messages() for p in prompts]
--> 698 return self.generate(prompt_messages, stop=stop, callbacks=callbacks, **kwargs)
699
700 async def agenerate_prompt(

/usr/local/lib/python3.10/dist-packages/langchain_core/language_models/chat_models.py in generate(self, messages, stop, callbacks, tags, metadata, run_name, run_id, **kwargs)
553 if run_managers:
554 run_managers[i].on_llm_error(e, response=LLMResult(generations=[]))
--> 555 raise e
556 flattened_outputs = [
557 LLMResult(generations=[res.generations], llm_output=res.llm_output) # type: ignore[list-item]

/usr/local/lib/python3.10/dist-packages/langchain_core/language_models/chat_models.py in generate(self, messages, stop, callbacks, tags, metadata, run_name, run_id, **kwargs)
543 try:
544 results.append(
--> 545 self._generate_with_cache(
546 m,
547 stop=stop,

/usr/local/lib/python3.10/dist-packages/langchain_core/language_models/chat_models.py in _generate_with_cache(self, messages, stop, run_manager, **kwargs)
768 else:
769 if inspect.signature(self._generate).parameters.get("run_manager"):
--> 770 result = self._generate(
771 messages, stop=stop, run_manager=run_manager, **kwargs
772 )

/usr/local/lib/python3.10/dist-packages/langchain_google_genai/chat_models.py in _generate(self, messages, stop, run_manager, tools, functions, safety_settings, tool_config, generation_config, **kwargs)
765 generation_config=generation_config,
766 )
--> 767 response: GenerateContentResponse = _chat_with_retry(
768 request=request,
769 **kwargs,

/usr/local/lib/python3.10/dist-packages/langchain_google_genai/chat_models.py in _chat_with_retry(generation_method, **kwargs)
194 raise e
195
--> 196 return _chat_with_retry(**kwargs)
197
198

/usr/local/lib/python3.10/dist-packages/tenacity/init.py in wrapped_f(*args, **kw)
334 copy = self.copy()
335 wrapped_f.statistics = copy.statistics # type: ignore[attr-defined]
--> 336 return copy(f, *args, **kw)
337
338 def retry_with(*args: t.Any, **kwargs: t.Any) -> WrappedFn:

/usr/local/lib/python3.10/dist-packages/tenacity/init.py in call(self, fn, *args, **kwargs)
473 retry_state = RetryCallState(retry_object=self, fn=fn, args=args, kwargs=kwargs)
474 while True:
--> 475 do = self.iter(retry_state=retry_state)
476 if isinstance(do, DoAttempt):
477 try:

/usr/local/lib/python3.10/dist-packages/tenacity/init.py in iter(self, retry_state)
374 result = None
375 for action in self.iter_state.actions:
--> 376 result = action(retry_state)
377 return result
378

/usr/local/lib/python3.10/dist-packages/tenacity/init.py in (rs)
396 def _post_retry_check_actions(self, retry_state: "RetryCallState") -> None:
397 if not (self.iter_state.is_explicit_retry or self.iter_state.retry_run_result):
--> 398 self._add_action_func(lambda rs: rs.outcome.result())
399 return
400

/usr/lib/python3.10/concurrent/futures/_base.py in result(self, timeout)
449 raise CancelledError()
450 elif self._state == FINISHED:
--> 451 return self.__get_result()
452
453 self._condition.wait(timeout)

/usr/lib/python3.10/concurrent/futures/_base.py in __get_result(self)
401 if self._exception:
402 try:
--> 403 raise self._exception
404 finally:
405 # Break a reference cycle with the exception in self._exception

/usr/local/lib/python3.10/dist-packages/tenacity/init.py in call(self, fn, *args, **kwargs)
476 if isinstance(do, DoAttempt):
477 try:
--> 478 result = fn(*args, **kwargs)
479 except BaseException: # noqa: B902
480 retry_state.set_exception(sys.exc_info()) # type: ignore[arg-type]

/usr/local/lib/python3.10/dist-packages/langchain_google_genai/chat_models.py in _chat_with_retry(**kwargs)
188
189 except google.api_core.exceptions.InvalidArgument as e:
--> 190 raise ChatGoogleGenerativeAIError(
191 f"Invalid argument provided to Gemini: {e}"
192 ) from e

ChatGoogleGenerativeAIError: Invalid argument provided to Gemini: 400 * GenerateContentRequest.tools[0].function_declarations[0].parameters.properties[key_developments].items: missing field.

Description

Hi !

Since yesterday, I try to follow this official guide in the v0.2 documentation : https://python.langchain.com/v0.2/docs/how_to/extraction_long_text/

However, it doesn't work well with Chat Google Generative AI
The collab link is here, if you want to try : https://colab.research.google.com/drive/1BCat5tBZRcxUhjQ3vGJD3Zu1eiqYIAWz?usp=sharing

I have followed the guide step by step, but it keep having an error about missing field on the request.
For information, Chat Google Generative AI have Structured Output : https://python.langchain.com/v0.2/docs/integrations/chat/google_generative_ai/
And also, it's not about my location either (I have already success for others use of Chat Google Generative AI)

I have try differents things with schema, and I go to the conclusion that I can't use scheme that define other scheme in it like (or List):

class ExtractionData(BaseModel):
    """Extracted information about key developments in the history of cars."""

    key_developments: List[KeyDevelopment]

However I can use without problem this scheme :

class KeyDevelopment(BaseModel):
    """Information about a development in the history of cars."""

    year: int = Field(
        ..., description="The year when there was an important historic development."
    )
    description: str = Field(
        ..., description="What happened in this year? What was the development?"
    )
    evidence: str = Field(
        ...,
        description="Repeat in verbatim the sentence(s) from which the year and description information were extracted",
    )

(but responses with scheme tend to have very bad result with Chat Google, like it's 90% time non-sense)

Sorry for my english which is not really perfect and thank you for reading me !

• ToyHugs

System Info

https://colab.research.google.com/drive/1BCat5tBZRcxUhjQ3vGJD3Zu1eiqYIAWz?usp=sharing

[Mikatux]

Same issue with a simple structured output.

Like in the langGraph tutorial, I am trying to use a List in with_structured_output with ChatGoogleGenerativeAI.

from langchain_google_genai import ChatGoogleGenerativeAI
from langchain_core.pydantic_v1 import BaseModel, Field

from typing import  List

class Plan(BaseModel):
    steps: List[str] = Field(
        description="different steps to follow, should be in sorted order"
    )

model = ChatGoogleGenerativeAI(model="gemini-1.5-flash", temperature=0.2, verbose=True).with_structured_output(Plan)

print(model.invoke("what is the hometown of the current Australia open winner?"))

And the error :

raise ChatGoogleGenerativeAIError(
langchain_google_genai.chat_models.ChatGoogleGenerativeAIError: Invalid argument provided to Gemini: 400 * GenerateContentRequest.tools[0].function_declarations[0].parameters.properties[setup].items: missing field.

Without the List it works like a charm

[mbyx]

I am also having the same issue, just like @Mikatux, I am using ChatGoogleGenerativeAI with the tutorial code, and have the same error. Without List, it works as well.

[glsch]

Same issue. However, in my case this works unreliably when my schema inherits from BaseModel and does not works at all whenever I try to pass a TypedDict-based output model. In the documentation it's said that it must work...

[calcea]

Same here. If I have a list parameter in my tool input model I receive the same error.

[muriloime]

same here . Is there an workaround for this?

[Nachoeigu]

Yes, the same me.

[rohit-mapakshi97]

I had a similar issue. After playing around for a while I found the following solutions.
Alternative 1: Naive approach
Update your prompt with an additional line like "the output should be a JSON object with 'entities' as key with the list of names populated as list. No Preamble"
Alternative 2:

from langchain_core.utils.function_calling import convert_to_openai_function
dict_schema = convert_to_openai_function(Entities)
entity_chain = prompt | llm.with_structured_output(dict_schema)

Alternative 2 worked for me. Reference. Note: My LLM is ChatGoogleGenerativeAI not ChatVertexAI, but it still works!

[pinkponk]

from langchain_google_genai import ChatGoogleGenerativeAI
from langchain_core.pydantic_v1 import BaseModel, Field

class Plan(BaseModel):
    steps: str = Field(
        description="different steps to follow, should be in sorted order"
    )


model = ChatGoogleGenerativeAI(model="gemini-1.5-flash", temperature=0.2, verbose=True).with_structured_output(Plan)

print(model.invoke("what is the hometown of the current Australia open winner?"))

This gets me None

using convert_to_openai_function gets me [] instead.

with_structured_output seems broken for ChatGoogleGenerativeAI?

[pinkponk]

Holy damn I just realized that this is just because the model just don't want to answer. see this code

from langchain_google_genai import ChatGoogleGenerativeAI
from langchain_core.pydantic_v1 import BaseModel, Field


llm = ChatGoogleGenerativeAI(model="gemini-1.5-flash", temperature=0.2, verbose=True)


class Plan(BaseModel):
    '''Plan to be aswesome'''
    steps: str = Field(description="different steps to follow to be awesome")


model = llm.with_structured_output(Plan)

print(model.invoke("what is the hometown of the current Australia open winner?")) # <--- This returns None !!!!!!!!
print(model.invoke("How should I be awesome?")) # <--- This returns something

Is there a setting to force the model to answer? lazy model?

[muriloime]

My two cents:

libraries like langchain/litellm/etc are not fast enough to cope with google/openai sdk/api updates. I migrated this part of my code to use vanilla google gemini api and had much better results.

That said, I think it is a hard problem to solve ( unify the apis in such a fast changing api landscape)

[derevyan]

Any one fix it somehow?

[moveyor]

I switched to Vertex AI which works for me, but it's not ideal given different quotas / rate limits between the two services.

from langchain_google_vertexai import ChatVertexAI
from pydantic import BaseModel, Field

class VertexOutputModel(BaseModel):
    age: int = Field(..., description="Age of user")


vertex_llm = ChatVertexAI(
    model="gemini-1.5-flash",
    temperature=0,
    max_output_tokens=2048,
    stream=False,
).with_structured_output(VertexOutputModel)

[alexminza]

I get another error with a similar example:

Exception has occurred: TypeError
list indices must be integers or slices, not str
  File "/path/test.py", line XXX, in test
    .with_structured_output(schema=TestModel2)
     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "<string>", line 1, in <module>
TypeError: list indices must be integers or slices, not str

Test example pseudocode:

class TestModel1(BaseModel):
    test: str = Field(description="Test")

class TestModel2(BaseModel):
    test: list[TestModel1]

[derevyan]

Any updates here?

[alexminza]

Any updates here?

@baskaryan any luck?

[alexminza]

from enum import Enum
from pydantic import BaseModel, Field

from dotenv import load_dotenv, find_dotenv
_ = load_dotenv(find_dotenv())

from langchain_core.messages import HumanMessage
from langchain_anthropic import ChatAnthropic
from langchain_google_genai import ChatGoogleGenerativeAI

class TestModel1(BaseModel):
    """Test attribute definition"""
    test: str = Field(description="Test")

class TestModel2(BaseModel):
    """Extracts a list of test attributes"""
    test: list[TestModel1]


model_anthropic = ChatAnthropic(model='claude-3-5-sonnet-latest', temperature=0) \
    .with_structured_output(schema=TestModel2.model_json_schema())

model_google = ChatGoogleGenerativeAI(model='models/gemini-1.5-pro-latest', temperature=0) \
    .with_structured_output(schema=TestModel2.model_json_schema())


query = """Test1, Test2, Test3"""
messages = [HumanMessage(query)]
response_anthropic = model_anthropic.invoke(input=messages)
response_google = model_google.invoke(input=messages)

print(response_anthropic)
print(response_google)

{'test': [{'test': 'Test1'}, {'test': 'Test2'}, {'test': 'Test3'}]}
[{'args': {}, 'type': 'TestModel2'}]

[alexminza]

model_google = ChatGoogleGenerativeAI(model='models/gemini-1.5-pro-latest', temperature=0) \
    .with_structured_output(schema=TestModel2, include_raw=True)

Value 'Test attribute definition' is not supported in schema, ignoring v=Test attribute definition
Value '['test']' is not supported in schema, ignoring v=['test']
Value 'TestModel1' is not supported in schema, ignoring v=TestModel1
Value 'object' is not supported in schema, ignoring v=object
Value 'Test attribute definition' is not supported in schema, ignoring v=Test attribute definition
Value '['test']' is not supported in schema, ignoring v=['test']
Value 'TestModel1' is not supported in schema, ignoring v=TestModel1
Value 'object' is not supported in schema, ignoring v=object
{'name': 'TestModel2', 'description': 'Extracts a list of test attributes', 'parameters': {'type_': 6, 'properties': {'test': {'type_': 5, 'items': {'type_': 1, 'format_': '', 'description': '', 'nullable': False, 'enum': [], 'max_items': '0', 'min_items': '0', 'properties': {}, 'required': []}, 'format_': '', 'description': '', 'nullable': False, 'enum': [], 'max_items': '0', 'min_items': '0', 'properties': {}, 'required': []}}, 'required': ['test'], 'format_': '', 'description': '', 'nullable': False, 'enum': [], 'max_items': '0', 'min_items': '0'}}
{'raw': AIMessage(content='', additional_kwargs={'function_call': {'name': 'TestModel2', 'arguments': '{"test": ["Test1", "Test2", "Test3"]}'}}, response_metadata={'prompt_feedback': {'block_reason': 0, 'safety_ratings': []}, 'finish_reason': 'STOP', 'safety_ratings': [{'category': 'HARM_CATEGORY_DANGEROUS_CONTENT', 'probability': 'NEGLIGIBLE', 'blocked': False}, {'category': 'HARM_CATEGORY_HATE_SPEECH', 'probability': 'NEGLIGIBLE', 'blocked': False}, {'category': 'HARM_CATEGORY_HARASSMENT', 'probability': 'NEGLIGIBLE', 'blocked': False}, {'category': 'HARM_CATEGORY_SEXUALLY_EXPLICIT', 'probability': 'NEGLIGIBLE', 'blocked': False}]}, id='run-a2b4c849-ee1b-4220-b16a-e0133fc4523e-0', tool_calls=[{'name': 'TestModel2', 'args': {'test': ['Test1', 'Test2', 'Test3']}, 'id': 'b6aa2cdb-087d-4560-b4d9-3849d6abb371', 'type': 'tool_call'}], usage_metadata={'input_tokens': 50, 'output_tokens': 24, 'total_tokens': 74}), 'parsing_error': 3 validation errors for TestModel2
test.0
  Input should be a valid dictionary or instance of TestModel1 [type=model_type, input_value='Test1', input_type=str]
    For further information visit https://errors.pydantic.dev/2.9/v/model_type
test.1
  Input should be a valid dictionary or instance of TestModel1 [type=model_type, input_value='Test2', input_type=str]
    For further information visit https://errors.pydantic.dev/2.9/v/model_type
test.2
  Input should be a valid dictionary or instance of TestModel1 [type=model_type, input_value='Test3', input_type=str]
    For further information visit https://errors.pydantic.dev/2.9/v/model_type, 'parsed': None}

[alexminza]

model_google = ChatGoogleGenerativeAI(model='models/gemini-1.5-pro-latest', temperature=0) \
    .with_structured_output(schema=TestModel2.model_json_schema(), include_raw=True)

{'$defs': {'TestModel1': {'description': 'Test attribute definition', 'properties': {'test': {'description': 'Test', 'title': 'Test', 'type': 'string'}}, 'required': ['test'], 'title': 'TestModel1', 'type': 'object'}}, 'description': 'Extracts a list of test attributes', 'properties': {'test': {'items': {'$ref': '#/$defs/TestModel1'}, 'title': 'Test', 'type': 'array'}}, 'required': ['test'], 'title': 'TestModel2', 'type': 'object', 'parameters': {}}
{'$defs': {'TestModel1': {'description': 'Test attribute definition', 'properties': {'test': {'description': 'Test', 'title': 'Test', 'type': 'string'}}, 'required': ['test'], 'title': 'TestModel1', 'type': 'object'}}, 'description': 'Extracts a list of test attributes', 'properties': {'test': {'items': {'$ref': '#/$defs/TestModel1'}, 'title': 'Test', 'type': 'array'}}, 'required': ['test'], 'title': 'TestModel2', 'type': 'object', 'parameters': {}}
{'name': 'TestModel2', 'description': 'Extracts a list of test attributes', 'parameters': {}}
WARNING: All log messages before absl::InitializeLog() is called are written to STDERR
I0000 00:00:1730140541.769303 2729666 fork_posix.cc:77] Other threads are currently calling into gRPC, skipping fork() handlers
{'raw': AIMessage(content='', additional_kwargs={'function_call': {'name': 'TestModel2', 'arguments': '{}'}}, response_metadata={'prompt_feedback': {'block_reason': 0, 'safety_ratings': []}, 'finish_reason': 'STOP', 'safety_ratings': [{'category': 'HARM_CATEGORY_DANGEROUS_CONTENT', 'probability': 'NEGLIGIBLE', 'blocked': False}, {'category': 'HARM_CATEGORY_HARASSMENT', 'probability': 'NEGLIGIBLE', 'blocked': False}, {'category': 'HARM_CATEGORY_HATE_SPEECH', 'probability': 'NEGLIGIBLE', 'blocked': False}, {'category': 'HARM_CATEGORY_SEXUALLY_EXPLICIT', 'probability': 'NEGLIGIBLE', 'blocked': False}]}, id='run-d841bf55-f7ec-453b-a958-a0ccbeffe9ae-0', tool_calls=[{'name': 'TestModel2', 'args': {}, 'id': 'db62faf6-299e-4331-9f16-059876ccc819', 'type': 'tool_call'}], usage_metadata={'input_tokens': 37, 'output_tokens': 10, 'total_tokens': 47}), 'parsed': [{'args': {}, 'type': 'TestModel2'}], 'parsing_error': None}

[alexminza]

However, this code "kind-of" works:

model_google = ChatGoogleGenerativeAI(model='models/gemini-1.5-pro-latest', temperature=0) \
    .bind_tools([TestModel2], tool_choice='any')

...

print(response_google.additional_kwargs['function_call']['arguments'])

{"test": ["Test1", "Test2", "Test3"]}

Reference: langchain-ai/langchain-google#469

[alexminza]

There seems to be a workaround:

from langchain_core.utils.function_calling import convert_to_openai_function

model_google = ChatGoogleGenerativeAI(model='models/gemini-1.5-pro-latest', temperature=0) \
    .with_structured_output(schema=convert_to_openai_function(TestModel2))

Reference: langchain-ai/langchain-google#299