# Deep Agents from Scratch – LangChain Search Agent

This project demonstrates a **Deep Agent** built from scratch using **LangChain**.  
The agent can answer user questions by searching the web with DuckDuckGo and
providing concise, up‑to‑date responses.

> **Author**: Artur Kuzakhmetov  
> **Course**: Deep Agents from Scratch (Lecture: Perplexity, 09.04.2026)  
> **Deadline**: 31.08.2026

---

## Features

- **Custom Search Tool** – queries DuckDuckGo’s instant answer API.
- **Conversation Memory** – keeps context across turns.
- **REACT Agent** – follows the “Reason → Act → Think” pattern.
- **CLI** – simple command‑line interface for interactive use.
- **Unit Tests** – basic tests for the search tool.

---

## Setup

1. **Clone the repository**

   ```bash
   git clone https://git.brojs.ru/kuzakhmetovartur/8.-samopisnyy-poiskovyy-agent-na-osnove-.git
   cd 8.-samopisnyy-poiskovyy-agent-na-osnove-
   ```

2. **Create a virtual environment**

   ```bash
   python -m venv .venv
   source .venv/bin/activate   # On Windows: .venv\Scripts\activate
   ```

3. **Install dependencies**

   ```bash
   pip install -r requirements.txt
   ```

4. **Set up OpenAI API key**

   Create a `.env` file in the project root:

   ```dotenv
   OPENAI_API_KEY=sk-...
   ```

   Replace `sk-...` with your actual key.

---

## Usage

Run the agent:

```bash
python -m src.index
```

You will see:

```
Deep Agents from Scratch - LangChain Search Agent
Type 'exit' or 'quit' to stop.

Enter your question:
```

Type a question, e.g.:

```
What is the capital of France?
```

The agent will search the web and return an answer.

---

## Running Tests

```bash
python -m unittest discover -s tests
```

---

## Project Structure

```
├── src
│   └── index.py          # Main agent implementation
├── tests
│   └── test_search_tool.py  # Unit tests for the search tool
├── requirements.txt      # Project dependencies
└── README.md             # Documentation
```

---

## Contributing

Feel free to fork the repository, create a feature branch, and submit a pull request.  
Please ensure tests pass before merging.

---

## License

MIT License.