# RAG Memory Agent

A simple Retrieval-Augmented Generation (RAG) memory system built with Node.js, TypeScript, and Express.  
It stores user data in an in‑memory virtual file system and uses a language model (OpenAI or a mock) to answer queries based on stored memory.

## Features

- **Virtual File System** – CRUD operations for memory entries.
- **LLM abstraction** – Uses OpenAI GPT‑3.5‑Turbo if `OPENAI_API_KEY` is set, otherwise falls back to a mock echo.
- **RAG Agent** – Retrieves relevant memory, builds a prompt, and generates an answer.
- **RESTful API** – Endpoints for managing memory and querying the agent.
- **Unit tests** – Jest tests for VFS and Agent logic.

## Installation

```bash
git clone https://git.brojs.ru/kuzakhmetovartur/prakticheskoe-zadanie-agent-s-rag-pamyat.git
cd prakticheskoe-zadanie-agent-s-rag-pamyat
npm install
```

## Environment Variables

Create a `.env` file based on `.env.example`:

```bash
cp .env.example .env
```

- `OPENAI_API_KEY` – (optional) Your OpenAI API key. If omitted, the agent will use a mock LLM.
- `PORT` – Port number for the server (default: 3000).

## Running the Server

```bash
npm run dev   # Development with ts-node
# or
npm run build
npm start
```

The server will start on `http://localhost:<PORT>`.

## API Endpoints

| Method | Path      | Description                                 | Body (JSON)                     |
|--------|-----------|---------------------------------------------|---------------------------------|
| GET    | `/memory` | List all memory entries (id, snippet).      | –                               |
| POST   | `/memory` | Create a new memory entry.                  | `{ "content": "string" }`       |
| DELETE | `/memory/:id` | Delete a memory entry by ID.            | –                               |
| POST   | `/query`  | Query the agent.                            | `{ "query": "string" }`         |

### Example Requests

```bash
# Add memory
curl -X POST http://localhost:3000/memory \
  -H "Content-Type: application/json" \
  -d '{"content":"I love programming in TypeScript."}'

# Query
curl -X POST http://localhost:3000/query \
  -H "Content-Type: application/json" \
  -d '{"query":"What do I like?"}'
```

## Testing

Run unit tests with coverage:

```bash
npm test
```

## Project Structure

```
src/
  index.ts          # Server entry point
  agent.ts          # RAG agent logic
  llm.ts            # LLM abstraction
  vfs.ts            # Virtual file system
  utils.ts          # Helpers
  routes.ts         # Express routes
  middleware.ts     # Error handling & validation
  tests/
    vfs.test.ts
    agent.test.ts
```

## License

MIT © Your Name