How to add prompt to Langchain ConversationalRetrievalChain chat over docs with history?

Question

Langchain have added this function ConversationalRetrievalChain which is used to chat over docs with history. According to their documentation here ConversationalRetrievalChain I need to pass prompts which are instructions to the function. How can i achieve that with this function call?

here is the code

qa = ConversationalRetrievalChain.from_llm(OpenAI(temperature=0), vectorstore.as_retriever(), memory=memory)

Why did you delete your answer? isnt it working? Do you have an answer to your own question that works? — Luis Valencia, Jun 26 '23 at 08:08

score 5 · Answer 1 · answered May 15 '23 at 07:06

You can pass your prompt in ConversationalRetrievalChain.from_llm() method with the combine_docs_chain_kwargs param. See the below example with ref to your provided sample code:

qa = ConversationalRetrievalChain.from_llm(
    llm=OpenAI(temperature=0),
    retriever=vectorstore.as_retriever(),
    combine_docs_chain_kwargs={"prompt": prompt}
)

If you see the source, the combine_docs_chain_kwargs then pass through the load_qa_chain() with your provided prompt.

score 0 · Answer 2 · answered Jun 18 '23 at 16:33

this code worked for me (Thanks to DennisPeeters) :

general_system_template = r""" 
Given a specific context, please give a short answer to the question, covering the required advices in general and then provide the names all of relevant(even if it relates a bit) products. 
 ----
{context}
----
"""
general_user_template = "Question:```{question}```"
messages = [
            SystemMessagePromptTemplate.from_template(general_system_template),
            HumanMessagePromptTemplate.from_template(general_user_template)
]
qa_prompt = ChatPromptTemplate.from_messages( messages )

return ConversationalRetrievalChain.from_llm(
            llm=ChatOpenAI(
                model_name=self.model_name,
                temperature=self.temperature,
                max_tokens=self.max_tokens,
            ),
            retriever=self.retriever,
            chain_type="stuff",
            verbose=self.verbose,
            , combine_docs_chain_kwargs={'prompt': qa_prompt}
        )

How to add prompt to Langchain ConversationalRetrievalChain chat over docs with history?

2 Answers2