graph/chains/answer_grader.py

from langchain_deepseek import ChatDeepSeek
from langchain_core.prompts import ChatPromptTemplate
from pydantic import BaseModel, Field

class GradeAnswer(BaseModel):
    binary_score: bool = Field(
        description="Answer addresses the question, 'yes' or 'no'"
    )

llm = ChatDeepSeek(model="deepseek-chat", temperature=0)
structured_llm_grader = llm.with_structured_output(GradeAnswer)

system_prompt = """
You are a grader assessing whether an answer addresses / resolves a question\n
Give a binary score 'yes' or 'no'. 'Yes' means that the answer resolves the question"""

answer_prompt = ChatPromptTemplate.from_messages(
    [
        ("system", system_prompt),
        ("human", "User question: \n\n {question} \n\n LLM generation: {generation}")
    ]
)

answer_grader = answer_prompt | structured_llm_grader