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116 lines
4.1 KiB
Python

import os
from functools import lru_cache
from typing import Any
from uuid import uuid4
from langchain.agents import create_agent
from langchain_core.documents import Document
from langchain_core.tools import tool
from langchain_ollama import ChatOllama, OllamaEmbeddings
from langchain_text_splitters import RecursiveCharacterTextSplitter
from langchain_qdrant import QdrantVectorStore
from qdrant_client import QdrantClient
OLLAMA_CHAT_MODEL = os.getenv("OLLAMA_CHAT_MODEL", "llama3")
OLLAMA_EMBED_MODEL = os.getenv("OLLAMA_EMBED_MODEL", "nomic-embed-text")
EMBEDDING_SIZE = int(os.getenv("OLLAMA_EMBEDDING_SIZE", "768"))
@lru_cache(maxsize=1)
def get_embeddings() -> OllamaEmbeddings:
return OllamaEmbeddings(model=OLLAMA_EMBED_MODEL)
@lru_cache(maxsize=1)
def get_vector_store() -> QdrantVectorStore:
client = QdrantClient()
# Ensure collection exists
client.recreate_collection(
collection_name="rag_memory",
vectors_config={"size": EMBEDDING_SIZE, "distance": "cosine"},
)
return QdrantVectorStore(client=client, collection_name="rag_memory")
def chunk_document(content: str, title: str) -> list[Document]:
splitter = RecursiveCharacterTextSplitter(chunk_size=500, chunk_overlap=100)
return splitter.create_documents([content], metadatas=[{"title": title}])
@tool
def search_knowledge_base(query: str, max_results: int = 3) -> str:
"""Search relevant chunks in the local Qdrant knowledge base."""
vector_store = get_vector_store()
results = vector_store.similarity_search_with_score(query, k=max_results)
if not results:
return "No relevant documents found."
lines: list[str] = []
for idx, (doc, score) in enumerate(results, start=1):
title = doc.metadata.get("title", "untitled") if doc.metadata else "untitled"
snippet = doc.page_content.replace("\n", " ")[:300]
lines.append(f"{idx}. {title} (score={score:.4f}): {snippet}")
return "\n".join(lines)
@tool
def add_to_knowledge_base(content: str, title: str) -> str:
"""Split content into chunks and store it in the local Qdrant knowledge base."""
documents = chunk_document(content, title)
ids = [str(uuid4()) for _ in documents]
embeddings = get_embeddings().embed_documents([doc.page_content for doc in documents])
vector_store = get_vector_store()
vector_store.add_documents(documents, ids=ids, embeddings=embeddings)
return f"Added {len(documents)} chunk(s) from '{title}' to the knowledge base."
def build_agent() -> Any:
llm = ChatOllama(model=OLLAMA_CHAT_MODEL)
return create_agent(
model=llm,
tools=[search_knowledge_base, add_to_knowledge_base],
system_prompt=(
"You are a RAG assistant. Use search_knowledge_base before answering "
"questions that may depend on stored knowledge, and use "
"add_to_knowledge_base when the user asks to remember information."
),
)
def run_cli() -> None:
print("RAG agent. Commands: /add <title> | <content>, /search <query>, /quit")
agent = None
while True:
try:
user_input = input(">>> ").strip()
except EOFError:
break
if not user_input:
continue
if user_input == "/quit":
break
if user_input.startswith("/add "):
payload = user_input[5:]
if "|" in payload:
title, content = [part.strip() for part in payload.split("|", 1)]
else:
title, content = "note", payload.strip()
print(add_to_knowledge_base.invoke({"content": content, "title": title}))
continue
if user_input.startswith("/search "):
query = user_input[8:].strip()
print(search_knowledge_base.invoke({"query": query, "max_results": 3}))
continue
if agent is None:
agent = build_agent()
response = agent.invoke({"messages": [{"role": "user", "content": user_input}]})
messages = response.get("messages", [])
print(messages[-1].content if messages else response)
if __name__ == "__main__":
run_cli()