Files
patchy631--ai-engineering-hub/llama-4-rag/app.py
T
2026-07-13 12:37:47 +08:00

187 lines
6.8 KiB
Python

import os
from dotenv import load_dotenv
# Load environment variables
load_dotenv()
import base64
import gc
import random
import tempfile
import time
import uuid
from IPython.display import Markdown, display
from llama_index.core import Settings
from llama_index.llms.cerebras import Cerebras
from llama_index.core import PromptTemplate
from llama_index.embeddings.fastembed import FastEmbedEmbedding
from llama_index.core import VectorStoreIndex, ServiceContext, SimpleDirectoryReader
import streamlit as st
if "id" not in st.session_state:
st.session_state.id = uuid.uuid4()
st.session_state.file_cache = {}
session_id = st.session_state.id
client = None
@st.cache_resource
def load_llm():
llm = Cerebras(model="meta-llama/Llama-4-Maverick-17B-128E-Instruct-FP8",
api_key=os.getenv("CEREBRAS_API_KEY"))
return llm
def reset_chat():
st.session_state.messages = []
st.session_state.context = None
gc.collect()
def display_pdf(file):
st.markdown("### PDF Preview")
base64_pdf = base64.b64encode(file.read()).decode("utf-8")
pdf_display = f"""<iframe src="data:application/pdf;base64,{base64_pdf}" width="400" height="100%" type="application/pdf"
style="height:100vh; width:100%"
>
</iframe>"""
st.markdown(pdf_display, unsafe_allow_html=True)
with st.sidebar:
# Add API Key Input
col1, col2 = st.columns([1, 3])
with col1:
# Add vertical space to align with header
st.write("")
st.image("./assets/cerebras.png", width=200)
# with col2:
# st.header("Groq Configuration")
# st.write("Groq API Key")
# Add hyperlink to get API key
st.markdown("[Get your API key](https://www.cerebras.ai/)", unsafe_allow_html=True)
api_key_input = st.text_input("Enter your Cerebras API Key:", type="password", key="api_key_input")
# Store API Key in session state if provided
if api_key_input:
st.session_state.groq_api_key = api_key_input
st.header(f"Add your documents!")
uploaded_file = st.file_uploader("Choose your `.pdf` file", type="pdf")
if uploaded_file:
try:
with tempfile.TemporaryDirectory() as temp_dir:
file_path = os.path.join(temp_dir, uploaded_file.name)
with open(file_path, "wb") as f:
f.write(uploaded_file.getvalue())
file_key = f"{session_id}-{uploaded_file.name}"
st.write("Indexing your document...")
if file_key not in st.session_state.get('file_cache', {}):
if os.path.exists(temp_dir):
loader = SimpleDirectoryReader(
input_dir=temp_dir,
required_exts=[".pdf"],
recursive=True
)
else:
st.error('Could not find the file you uploaded, please check again...')
st.stop()
docs = loader.load_data()
llm = load_llm()
embed_model = FastEmbedEmbedding(model_name="BAAI/bge-large-en-v1.5")
Settings.embed_model = embed_model
index = VectorStoreIndex.from_documents(docs, show_progress=True)
Settings.llm = llm
query_engine = index.as_query_engine(streaming=True)
qa_prompt_tmpl_str = (
"Context information is below.\n"
"---------------------\n"
"{context_str}\n"
"---------------------\n"
"Given the context information above I want you to think step by step to answer the query in a crisp manner, in case you don't know the answer say 'I don't know!'.\n"
"Query: {query_str}\n"
"Answer: "
)
qa_prompt_tmpl = PromptTemplate(qa_prompt_tmpl_str)
query_engine.update_prompts(
{"response_synthesizer:text_qa_template": qa_prompt_tmpl}
)
st.session_state.file_cache[file_key] = query_engine
else:
query_engine = st.session_state.file_cache[file_key]
st.success("Ready to Chat!")
display_pdf(uploaded_file)
except Exception as e:
st.error(f"An error occurred: {e}")
st.stop()
col1, col2 = st.columns([6, 1])
with col1:
# Removed the original header
st.markdown("<h2 style='color: #ffffff;'> RAG using Llama 4 </h2>", unsafe_allow_html=True)
# Replace text with image and subtitle styling
st.markdown("<div style='display: flex; align-items: center; gap: 10px;'><span style='font-size: 28px; color: #666;'>Powered by LlamaIndex</span><img src='data:image/png;base64,{}' width='50'> and <img src='data:image/png;base64,{}' width='125'></div>".format(
base64.b64encode(open("./assets/llamaindex.png", "rb").read()).decode(),
base64.b64encode(open("./assets/cerebras.png", "rb").read()).decode()
), unsafe_allow_html=True)
with col2:
st.button("Clear ↺", on_click=reset_chat)
# Initialize chat history
if "messages" not in st.session_state:
reset_chat()
# Logic to handle model selection and API Key
# Use API Key from session state if available, otherwise from environment variable
api_key = st.session_state.get("cerebras_api_key", os.getenv("CEREBRAS_API_KEY"))
if not api_key:
st.error("Please enter your Cerebras API Key in the sidebar or set the CEREBRAS_API_KEY environment variable.")
st.stop() # Stop execution if no API key is available
else:
# Configure the Groq client with the API key
Settings.llm = load_llm() # Reload LLM with potentially new key if model is selected *after* key entry
Settings.llm.api_key = api_key # Ensure the loaded LLM uses the correct key
# Display chat messages from history on app rerun
for message in st.session_state.messages:
with st.chat_message(message["role"]):
st.markdown(message["content"])
# Accept user input
if prompt := st.chat_input("What's up?"):
st.session_state.messages.append({"role": "user", "content": prompt})
with st.chat_message("user"):
st.markdown(prompt)
with st.chat_message("assistant"):
message_placeholder = st.empty()
full_response = ""
streaming_response = query_engine.query(prompt)
for chunk in streaming_response.response_gen:
full_response += chunk
message_placeholder.markdown(full_response + "▌")
message_placeholder.markdown(full_response)
st.session_state.messages.append({"role": "assistant", "content": full_response})