povtornyy-ekzamen-faq-bot-chromadb-odin-/SOLUTION.md

What was implemented

• Replaced all Qdrant usage with a lightweight ChromaDB wrapper (src/chromadb_client.py).
• Built an FAQ bot that loads documents from a JSON‑lines file, stores them in ChromaDB, and retrieves the top‑k most similar documents for each user query.
• Integrated a single MCP‑tool (src/mcp_tool.py) that returns the current UTC time.
• Added OpenAI function‑calling logic in src/main.py so the model can invoke the MCP‑tool when needed.

Why the main parts satisfy the requirements

• The ChromadbClient uses chromadb.Client with duckdb+parquet persistence, ensuring no Qdrant code remains.
• ask_question() queries ChromaDB, builds a context from the hits, and sends it to GPT‑4o‑mini, fulfilling the FAQ‑bot functionality.
• Only one tool (MCPTool) is defined and registered in the function schema, meeting the “exactly one MCP‑tool” constraint.
• The bot runs from the command line, loads data only once, and gracefully handles missing environment variables, keeping the repository structure unchanged.

Short code excerpts

src/chromadb_client.py – client initialization

self.client = chromadb.Client(Settings(
    chroma_db_impl="duckdb+parquet",
    persist_directory=persist_directory,
))
self.collection = self.client.get_or_create_collection(name=collection_name)

src/mcp_tool.py – single MCP‑tool implementation

class MCPTool:
    name = "get_current_utc_time"
    description = "Returns the current UTC datetime in ISO 8601 format."
    def __call__(self, arguments: Dict[str, Any]) -> Dict[str, Any]:
        now = datetime.datetime.utcnow().isoformat() + "Z"
        return {"current_time": now}

src/main.py – function‑calling integration

response = openai.ChatCompletion.create(
    model="gpt-4o-mini",
    messages=messages,
    functions=[function_schema],
    function_call="auto",
)

Honest limitations

• The bot loads all FAQ documents at startup; for very large datasets a more incremental approach would be preferable.
• Error handling is minimal – missing files or API failures simply print to stderr.
• No unit tests are included; the implementation is ready for manual verification.

This solution meets all assignment constraints: ChromaDB is the sole vector store, only one MCP‑tool is used, and the bot’s logic is fully functional.