Step by step guide on how to build an AI news summary using streamlit, groq and tavily

pip install langgraph==0.2.53 langgraph-checkpoint==2.0.6 langgraph-sdk==0.1.36 langchain-groq langchain-community langgraph-checkpoint-sqlite==2.0.1 tavily-python streamlit

import os
import sqlite3
from langgraph.graph import StateGraph
from langchain_core.messages import SystemMessage, HumanMessage
from langchain_groq import ChatGroq
from tavily import TavilyClient
from langgraph.checkpoint.sqlite import SqliteSaver
from typing import TypedDict, List
from pydantic import BaseModel
import streamlit as st

# Set API Keys
os.environ('TAVILY_API_KEY') = "your_tavily_key"
os.environ('GROQ_API_KEY') = "your_groq_key"

# Initialize Database for Checkpointing
sqlite_conn = sqlite3.connect("checkpoints.sqlite", check_same_thread=False)
memory = SqliteSaver(sqlite_conn)

# Initialize Model and Tavily Client
model = ChatGroq(model="Llama-3.1-8b-instant")
tavily = TavilyClient(api_key=os.environ("TAVILY_API_KEY"))

class AgentState(TypedDict):
    topic: str
    drafts: List(str)
    content: List(str)
    critiques: List(str)
    refined_summaries: List(str)
    headings: List(str)

BROWSING_PROMPT = """You are an ai news researcher tasked with finding the latest news articles on given topics. Generate up to 3 relevant search queries."""

WRITER_PROMPT = """You are an ai news summarizer. Write a detailed summary (1 to 2 paragraphs) based on the given content, ensuring factual correctness, clarity, and coherence."""

CRITIQUE_PROMPT = """You are a teacher reviewing draft summaries against the source content. Ensure factual correctness, identify missing or incorrect details, and suggest improvements.
----------
Content: {content}
----------"""

REFINE_PROMPT = """You are an ai news editor. Given a summary and critique, refine the summary accordingly.
-----------
Summary: {summary}"""

HEADING_GENERATION_PROMPT = """You are an ai news summarizer. Generate a short, descriptive headline for each news summary."""

from pydantic import BaseModel

class Queries(BaseModel):
    queries: List(str)

class News(BaseModel):
    news: List(str)

def browsing_node(state: AgentState):
    queries = model.with_structured_output(Queries).invoke((
        SystemMessage(content=BROWSING_PROMPT),
        HumanMessage(content=state('topic'))
    ))
    content = state.get('content', ())
    for q in queries.queries:
        response = tavily.search(query=q, max_results=2)
        for r in response('results'):
            content.append(r('content'))
    return {"content": content}

def writing_node(state: AgentState):
    content = "\n\n".join(state('content'))
    news = model.with_structured_output(News).invoke((
        SystemMessage(content=WRITER_PROMPT),
        HumanMessage(content=content)
    ))
    return {"drafts": news.news}

def reflection_node(state: AgentState):
    content = "\n\n".join(state('content'))
    critiques = ()
    for draft in state('drafts'):
        response = model.invoke((
            SystemMessage(content=CRITIQUE_PROMPT.format(content=content)),
            HumanMessage(content="draft: " + draft)
        ))
        critiques.append(response.content)
    return {"critiques": critiques}

def refine_node(state: AgentState):
    refined_summaries = ()
    for summary, critique in zip(state('drafts'), state('critiques')):
        response = model.invoke((
            SystemMessage(content=REFINE_PROMPT.format(summary=summary)),
            HumanMessage(content="Critique: " + critique)
        ))
        refined_summaries.append(response.content)
    return {"refined_summaries": refined_summaries}

def heading_node(state: AgentState):
    headings = ()
    for summary in state('refined_summaries'):
        response = model.invoke((
            SystemMessage(content=HEADING_GENERATION_PROMPT),
            HumanMessage(content=summary)
        ))
        headings.append(response.content)
    return {"headings": headings}

# Define Streamlit app
st.title("News Summarization Chatbot")

# Initialize session state
if "messages" not in st.session_state:
    st.session_state("messages") = ()

# Display past messages
for message in st.session_state("messages"):
    with st.chat_message(message("role")):
        st.markdown(message("content"))

# Input field for user
user_input = st.chat_input("Ask about the latest news...")

thread = 1
if user_input:
    st.session_state("messages").append({"role": "user", "content": user_input})
    with st.chat_message("assistant"):
        loading_text = st.empty()
        loading_text.markdown("*Thinking...*")

        builder = StateGraph(AgentState)
        builder.add_node("browser", browsing_node)
        builder.add_node("writer", writing_node)
        builder.add_node("reflect", reflection_node)
        builder.add_node("refine", refine_node)
        builder.add_node("heading", heading_node)
        builder.set_entry_point("browser")
        builder.add_edge("browser", "writer")
        builder.add_edge("writer", "reflect")
        builder.add_edge("reflect", "refine")
        builder.add_edge("refine", "heading")
        graph = builder.compile(checkpointer=memory)

        config = {"configurable": {"thread_id": f"{thread}"}}
        for s in graph.stream({"topic": user_input}, config):
            # loading_text.markdown(f"*{st.session_state('loading_message')}*")
            print(s)
        
        s = graph.get_state(config).values
        refined_summaries = s('refined_summaries')
        headings = s('headings')
        thread+=1
        # Display final response
        loading_text.empty()
        response_text = "\n\n".join((f"{h}\n{s}" for h, s in zip(headings, refined_summaries)))
        st.markdown(response_text)
        st.session_state("messages").append({"role": "assistant", "content": response_text})