# Interactive Text Adventure with LLM and Interrupts  

A minimal “Choose Your Own Story” game built on **LangGraph** that lets a large language model generate the narrative, pause for user input, and then continue based on the choice.

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## 📖 Overview

- The graph starts by asking an LLM to write the opening of a story and propose several actions.
- It then *interrupts* the flow, presenting those options in the console via **questionary**.
- After the player selects an option, the graph resumes and asks the LLM to finish the scene with that choice.

This demonstrates:
- State management with `TypedDict`
- Custom interrupt nodes (`langgraph.types.interrupt`)
- Human‑in‑the‑loop pattern
- Checkpointing (in‑memory in this example)

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## ⚙️ Installation

```bash
# Create a virtual environment (optional but recommended)
python -m venv .venv
source .venv/bin/activate   # Windows: .venv\Scripts\activate

# Install dependencies
pip install langgraph==0.1.9 \
          langchain==1.2.10 \
          langchain-openai==1.1.9 \
          questionary
```

> **OpenAI API key**  
> The script uses `ChatOpenAI` from LangChain, which requires an OpenAI key. Export it as an environment variable:

```bash
export OPENAI_API_KEY="sk-..."
# Windows: set OPENAI_API_KEY=sk-...
```

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## 📂 Project Structure

```
.
├── solution.py          # Main script – the graph definition and runner
└── README.md            # You’re reading it now
```

---

## 🚀 Running the Game

```bash
python solution.py
```

You’ll see something like:

```
LLM: "You find yourself in a dimly lit tavern..."
Options:
  1) Order a drink
  2) Ask about the town's rumors
  3) Leave immediately
Enter choice (1-3):
```

Type `1`, `2` or `3` and press **Enter**. The LLM will then generate a short continuation based on your selection.

---

## 📋 Example Session

```text
$ python solution.py
LLM: "You stand at the crossroads of destiny, with three paths before you..."
Options:
  1) Take the left path into the forest.
  2) Walk straight toward the looming castle.
  3) Turn back to the village.
Enter choice (1-3): 2

LLM: "You stride confidently toward the castle gates, feeling the weight of history upon your shoulders..."
```

Feel free to modify `solution.py` to add more nodes, change prompts, or persist checkpoints with a different saver.

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## 🔧 Customization Tips

| What | How |
|------|-----|
| **Different LLM** | Replace `ChatOpenAI()` with another LangChain model (e.g., Anthropic). |
| **Persisting state** | Swap `InMemorySaver` for `SQLiteSaver`, `RedisSaver`, etc. |
| **More complex choices** | Add additional interrupt nodes or loop back to earlier parts of the story. |

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## 📜 License

This project is provided as a learning example and may be freely used, modified, and distributed.

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