backend-fastapilisted

# Backend Architecture (FastAPI) ## Overview The backend is a **FastAPI** application located in `backend/`. It powers the chatbot and RAG functionality. ## Entry Point - **File**: `backend/main.py` - **Run**: `uvicorn backend.main:app --reload` (or via `npm run dev`) - **Port**: Defaults to `8000`. ## Endpoints ### `POST /api/chat` - **Purpose**: Main RAG chat endpoint. - **Input**: `ChatRequest` (query, history, user_context). - **Process**: 1. Embed query. 2. Search Qdrant (`search_qdrant`). 3. Build prompt (`build_rag_prompt`). 4. Generate Agent response. - **Output**: `ChatResponse` (answer, contexts). ### `POST /api/ask-selection` - **Purpose**: Targeted Q&A on selected text. - **Input**: `AskSelectionRequest` (question, selected_text). - **Process**: 1. Validates selection length. 2. Builds selection-specific prompt. 3. specific Agent instructions. ## Dependencies & Utils - `backend/utils/config.py`: Qdrant initialization. - `backend/utils/helpers.py`: Embedding and Prompt building logic. - `backend/models.py`: OpenAI/Gemini client setup. ## Environment Variables - `GEMINI_API_KEY`: For LLM and Embeddings. - `QDRANT_URL`, `QDRANT_API_KEY`: Vector DB connection.