Colossal Cave Adventure over Gemini

A faithful port of the classic 350-point Colossal Cave Adventure (Crowther & Woods, 1977) served over the Gemini protocol. Players explore the cave, solve puzzles, and collect treasure — all through a Gemini client.

Built with xitzin (a Gemini web framework) and nauyaca (a Gemini server).

Features

• Full 350-point game with all rooms, items, puzzles, and encounters from the original
• Player authentication via Gemini client certificates
• Per-player game state persisted in SQLite
• Dwarf and pirate encounters with faithful AI behavior
• Structured logging with optional fingerprint hashing for privacy

Quickstart

Requires Python 3.13+ and uv.

# Install dependencies
uv sync

# Generate TLS certificates (required for Gemini)
openssl req -x509 -newkey ec -pkeyopt ec_paramgen_curve:prime256v1 \
  -days 365 -nodes -keyout key.pem -out cert.pem \
  -subj "/CN=localhost"

# Start the server
ADVENTURE_CERTFILE=cert.pem ADVENTURE_KEYFILE=key.pem uv run adventure

Then connect with any Gemini client to gemini://localhost:1965/.

Configuration

All settings are read from environment variables prefixed with ADVENTURE_:

Project Structure

src/adventure/
├── engine/          # Synchronous, pure-Python game logic
│   ├── world.py     # Immutable data structures (Room, Obj, Word, Hint, World)
│   ├── state.py     # Mutable GameState (position, inventory, lamp, dwarves, score)
│   ├── loader.py    # Parses the 12-section advent.dat into a World
│   └── commands.py  # Command dispatch: movement, items, puzzles, combat, scoring
├── routes/          # Xitzin route handlers
│   ├── play.py      # Game routes (require client certificate)
│   └── home.py      # Public pages: /, /help, /about
├── templates/       # Jinja2 .gmi templates for Gemtext responses
├── app.py           # App factory
├── config.py        # Configuration from environment variables
├── logging.py       # structlog setup
├── models.py        # SQLModel entities (Player, SavedGame)
├── session.py       # Load/save/reset game state from DB
└── users.py         # Player upsert by fingerprint
data/
└── advent.dat       # Original game data file

Development

# Run tests
uv run pytest

# Lint and format
uv run ruff check src/ tests/
uv run ruff format src/ tests/

# Type check
uv run ty check src/

Credits

• Original game: Will Crowther (1976) and Don Woods (1977)
• Data file format: Public domain
• Parsing reference: Brandon Rhodes' python-adventure (Apache 2.0)

License

MIT