VertexAIModelGarden, cuts the response DeepSeek R1 (dep. from HuggingFace)

[XinyueZ]

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

Via VertexAIModelGarden almost nothing worked

from langchain_google_vertexai import VertexAI, ChatVertexAI, VertexAIEmbeddings
from langchain_google_vertexai import VertexAIModelGarden
from langchain_core.prompts import ChatPromptTemplate
from pydantic import BaseModel, Field

lm = VertexAIModelGarden(
    location="europe-west4",
    endpoint_id="11111186688",
    temperature=0,
    max_tokens=4096,
    top_p=1.0,
    top_k=-1,
    verbose=True,
)

prompt = ChatPromptTemplate.from_messages([("human", "Some questions: {input}")])

chain = prompt | lm
result = chain.invoke(
    {
        "input": "Wie sieht die Stadt Hamburg aus?",
    }
)

Via REST I did get rich output:

### Try vertexai huggingface model
POST https://europe-west4-aiplatform.googleapis.com/v1/projects/111122222/locations/europe-west4/endpoints/11111166666:predict
Content-Type: application/json
Authorization: Bearer ysdfasdfsdfasdfasfsdfasdfasdfasfsdfasfasdfasdfasdfasdf

{
    "instances": [
        {
            "prompt": "Wie sieht die Stadt Hamburg aus?",
            "max_tokens": 4096,
            "temperature": 0,
            "top_p": 1.0,
            "top_k": -1
        }
    ]
}

Error Message and Stack Trace (if applicable)

No response

Description

I find that the same model I deployed and used with a REST API worked fine, but when using VertexAIModelGarden the result is significantly cut off. The model used is deepseek r1 from Hugging Face. Did I forget something?

System Info

google-ai-generativelanguage==0.6.10
google-api-core==2.23.0
google-api-python-client==2.152.0
google-auth==2.36.0
google-auth-httplib2==0.2.0
google-cloud-aiplatform==1.72.0
google-cloud-bigquery==3.27.0
google-cloud-core==2.4.1
google-cloud-resource-manager==1.13.0
google-cloud-storage==2.18.2
google-crc32c==1.6.0
google-generativeai==0.8.3
google-resumable-media==2.7.2
googleapis-common-protos==1.66.0

langchain==0.3.7
langchain-anthropic==0.3.0
langchain-chroma==0.1.4
langchain-cohere==0.3.1
langchain-community==0.3.7
langchain-core==0.3.19
langchain-experimental==0.3.3
langchain-google-genai==2.0.4
langchain-google-vertexai==2.0.12
langchain-groq==0.2.1
langchain-ollama==0.2.0
langchain-openai==0.2.8
langchain-text-splitters==0.3.2
langchain_mistralai
langchain-xai==0.1.0
langgraph
langgraph-checkpoint
langgraph-checkpoint-sqlite
langgraph-sdk
langsmith==0.1.142