LLMRequestsChain not enforcing headers when making http requests

[paschembri]

System Info

LangChain version 0.0.201

Who can help?

@hwchase17 @agola

Information

• The official example notebooks/scripts
• My own modified scripts

Related Components

• LLMs/Chat Models
• Embedding Models
• Prompts / Prompt Templates / Prompt Selectors
• Output Parsers
• Document Loaders
• Vector Stores / Retrievers
• Memory
• Agents / Agent Executors
• Tools / Toolkits
• Chains
• Callbacks/Tracing
• Async

Reproduction

Based on the documentation example, run the following script:

from langchain.llms import OpenAI
from langchain.chains import LLMRequestsChain, LLMChain
from langchain.prompts import PromptTemplate

template = """Here is a company website content :
    ----
    {requests_result}
    ----
    We want to learn more about a company's activity and the kind of
    clients they target. Perform an analysis and write a short summary.
"""

PROMPT = PromptTemplate(
    input_variables=["requests_result"],
    template=template,
)

chain = LLMRequestsChain(llm_chain = LLMChain(llm=OpenAI(temperature=0), prompt=PROMPT))

print(chain.requests_wrapper)

Gives

python3 bug-langchain-requests.py
headers=None aiosession=None

Expected behavior

Provided headers should be enforced

python3 bug-langchain-requests.py
headers={'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.88 Safari/537.36'} aiosession=None