Updated main.py with Ollama embeddings and LangChain agent

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2026-07-02 16:45:49 +00:00
parent a2867c35d6
commit d9d826fae5
+70 -144
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@@ -1,162 +1,88 @@
import asyncio
import os
import json
from pathlib import Path
from langchain_openai import ChatOpenAI, OpenAIEmbeddings
from langchain_chroma import Chroma
from langchain_core.documents import Document
from langchain.tools import tool
from deepagents import create_deep_agent
from deepagents.backends import FilesystemBackend, LocalShellBackend, CompositeBackend
from langchain_core.messages import HumanMessage
from langchain_ollama import ChatOllama, OllamaEmbeddings
from langchain.embeddings import OpenAIEmbeddings
from langchain.vectorstores import Chroma
from langchain.agents import Tool, AgentExecutor, initialize_agent, AgentType
from langchain.tools import BaseTool
import httpx
import os
# ------------------------------------------------------------------
# Configuration
# ------------------------------------------------------------------
OPENAI_API_KEY = os.getenv("OPENAI_API_KEY")
if not OPENAI_API_KEY:
raise RuntimeError("OPENAI_API_KEY not set in environment")
# Load FAQ data
DATA_DIR = Path("data")
# ------------------------------------------------------------------
# LLM and embeddings (OpenRouter only)
# ------------------------------------------------------------------
llm = ChatOpenAI(
model="openai/gpt-oss-20b:free",
base_url="https://openrouter.ai/api/v1",
api_key=OPENAI_API_KEY,
temperature=0.0,
)
# Embedding model
embeddings = OllamaEmbeddings(model="nomic-embed-text")
embeddings = OpenAIEmbeddings(
model="text-embedding-3-small",
base_url="https://openrouter.ai/api/v1",
api_key=OPENAI_API_KEY,
)
# Create Chroma store
def load_faq_to_chroma() -> Chroma:
from langchain.document_loaders import TextLoader
from langchain.text_splitter import RecursiveCharacterTextSplitter
# ------------------------------------------------------------------
# Chroma vector store (persisted)
# ------------------------------------------------------------------
CHROMA_PATH = Path("./chroma_faq")
vector_store = Chroma(
collection_name="faq_collection",
embedding_function=embeddings,
persist_directory=str(CHROMA_PATH),
)
# ------------------------------------------------------------------
# Utility: load markdown files into Chroma
# ------------------------------------------------------------------
async def load_faq_to_chroma(md_dir: str = "data"):
md_dir = Path(md_dir)
if not md_dir.is_dir():
raise FileNotFoundError(f"Markdown directory {md_dir} not found")
docs = []
for md_file in md_dir.glob("*.md"):
text = md_file.read_text(encoding="utf-8")
docs.append(Document(page_content=text, metadata={"source": md_file.name}))
vector_store.add_documents(docs)
vector_store.persist()
print(f"Loaded {len(docs)} documents into Chroma (persisted at {CHROMA_PATH})")
for md_file in DATA_DIR.glob("*.md"):
loader = TextLoader(str(md_file))
docs.extend(loader.load_and_split(RecursiveCharacterTextSplitter(chunk_size=500, chunk_overlap=50)))
db = Chroma.from_documents(docs, embeddings, persist_directory="./chroma_faq")
db.persist()
return db
# ------------------------------------------------------------------
# Tools
# ------------------------------------------------------------------
@tool
def search_course_docs(query: str) -> str:
"""Search the local FAQ collection for relevant passages."""
results = vector_store.similarity_search(query, k=3)
if not results:
return "No relevant information found in the course materials."
return "\n---\n".join(f"[{doc.metadata.get('source', 'unknown')}] {doc.page_content}" for doc in results)
chroma_db = load_faq_to_chroma()
@tool
def fetch_course_meta(query: str) -> str:
"""Simulate an MCP-style tool that fetches course metadata.
In production this would be a real HTTP call to an MCP server.
Here we use a local JSON file as a mock response.
"""
meta_file = Path("meta.json")
if not meta_file.is_file():
return "Metadata source not available."
data = json.loads(meta_file.read_text(encoding="utf-8"))
# Very naive search: return items where query string appears in any value
matches = []
for key, value in data.items():
if isinstance(value, str) and query.lower() in value.lower():
matches.append(f"{key}: {value}")
if not matches:
return "No metadata matches found."
return "\n".join(matches)
# Tool: search in FAQ
class SearchFAQTool(BaseTool):
name = "search_course_docs"
description = "Search local FAQ docs. Use query string. Returns top k results."
# ------------------------------------------------------------------
# Backend setup
# ------------------------------------------------------------------
backend = CompositeBackend([
LocalShellBackend(workspace_dir="./workspace"),
FilesystemBackend(),
])
def _run(self, query: str, k: int = 3):
results = chroma_db.similarity_search_with_score(query, k)
return "\n".join([f"{i+1}. {r[0].page_content[:200]}... (score: {r[1]:.4f})" for i, r in enumerate(results)])
# ------------------------------------------------------------------
# DeepAgent creation
# ------------------------------------------------------------------
agent = create_deep_agent(
model=llm,
tools=[search_course_docs, fetch_course_meta],
backend=backend,
system_prompt=(
"You are a helpful FAQ assistant for the course. "
"When answering a question, use the local Chroma database if the answer is about course content. "
"If the question is about schedule, metadata, or other non-content info, call fetch_course_meta. "
"Always indicate the source in your final answer as either 'source: chroma' or 'source: mcp_meta'."
),
search_tool = SearchFAQTool()
# Tool: fetch course metadata (MCP style)
class FetchMetaTool(BaseTool):
name = "fetch_course_meta"
description = "Fetch course metadata via HTTP. Use query string. Returns JSON string."
def _run(self, query: str):
# For demo, use local JSON file or mock endpoint
url = f"http://localhost:8000/meta?query={query}"
try:
resp = httpx.get(url, timeout=5)
resp.raise_for_status()
return resp.text
except Exception as e:
return f"Error fetching meta: {e}"
meta_tool = FetchMetaTool()
# LLM
llm = ChatOllama(model="llama3")
# Agent
tools = [search_tool, meta_tool]
agent = initialize_agent(
tools,
llm,
agent=AgentType.ZERO_SHOT_REACT_DESCRIPTION,
verbose=True,
handle_parsing_errors=True,
)
# ------------------------------------------------------------------
# CLI helpers
# ------------------------------------------------------------------
PRESET_QUESTIONS = [
"What topics are covered in the first lecture?",
"Explain the concept of recursion as described in the notes.",
"When is the next lab session scheduled?",
]
async def run_interactive():
print("--- FAQ Bot CLI ---")
print("Type 'exit' to quit.")
while True:
user_input = input("\nQuestion: ")
if user_input.lower() in {"exit", "quit"}:
break
result = await agent.ainvoke(
{"messages": [HumanMessage(content=user_input)]},
{"configurable": {"thread_id": "session-1"}},
)
# The last message is the assistant's reply
reply = result["messages"][-1].content
print("\nAnswer:\n", reply)
async def run_presets():
for q in PRESET_QUESTIONS:
print("\nQuestion:", q)
result = await agent.ainvoke(
{"messages": [HumanMessage(content=q)]},
{"configurable": {"thread_id": "session-1"}},
)
reply = result["messages"][-1].content
print("Answer:\n", reply)
# ------------------------------------------------------------------
# Main entry point
# ------------------------------------------------------------------
async def main():
# Load data into Chroma if not already persisted
if not CHROMA_PATH.is_dir() or not any(CHROMA_PATH.iterdir()):
await load_faq_to_chroma()
# Run preset questions first
await run_presets()
# Then interactive mode
await run_interactive()
# Simple CLI with predefined questions
questions = [
"What is the deadline for assignment 3?",
"How to use ChromaDB with LangChain?",
"What is the schedule for next week?",
]
for q in questions:
print("\nQuestion:", q)
result = await agent.arun(input=q)
print("Answer:\n", result)
if __name__ == "__main__":
asyncio.run(main())