mcp-server-if

An MCP (Model Context Protocol) server for playing interactive fiction games. Enables AI assistants like Claude to play text adventure games through a standardized interface.

Features

• Play Glulx (.ulx, .gblorb) and Z-machine (.z3-.z8, .zblorb) games
• Automatic game state persistence (save/restore between sessions)
• Download games directly from the IF Archive
• Optional journaling mode for reflective playthroughs
• Works with Claude Desktop, Claude Code, and other MCP clients
• Bundled interpreters (glulxe for Glulx, bocfel for Z-machine)

Installation

# Using uvx (recommended)
uvx mcp-server-if

# Or install with pip
pip install mcp-server-if

The package includes pre-compiled interpreters. No additional setup required.

Configuration

Environment Variables

Variable	Description	Default
IF_GAMES_DIR	Directory to store games	~/.mcp-server-if/games
IF_GLULXE_PATH	Override path to glulxe binary	Bundled binary
IF_BOCFEL_PATH	Override path to bocfel binary	Bundled binary
IF_REQUIRE_JOURNAL	Require journal reflections	false

Command Line Arguments

mcp-server-if --help

Options:
  --games-dir PATH       Directory to store games
  --glulxe-path PATH     Path to glulxe binary (overrides bundled)
  --require-journal      Require journal reflections between turns

Usage with Claude Desktop

Add to your Claude Desktop configuration (~/Library/Application Support/Claude/claude_desktop_config.json on macOS or %APPDATA%\Claude\claude_desktop_config.json on Windows):

{
  "mcpServers": {
    "interactive-fiction": {
      "command": "uvx",
      "args": ["mcp-server-if"]
    }
  }
}

Usage with Claude Code

claude mcp add interactive-fiction -- uvx mcp-server-if

Available Tools

play_if

Play a turn of interactive fiction.

play_if(game="zork", command="go north")
play_if(game="zork", command="", journal="...reflection...")  # with journaling

list_games

List available games and their save state status.

download_game

Download a game from the IF Archive or any URL.

download_game(name="advent", url="advent.ulx")
download_game(name="bronze", url="https://example.com/Bronze.gblorb")

reset_game

Reset a game to start fresh (clears save state, preserves journal).

read_journal

Read the playthrough journal for a game.

read_journal(game="zork", recent=10)  # last 10 entries

search_journal

Search journal entries by keyword.

search_journal(game="zork", query="treasure")

Supported Game Formats

Glulx (modern, uses glulxe interpreter):

• .ulx - Raw Glulx game files
• .gblorb - Blorb containers with Glulx games

Z-machine (classic Infocom format, uses bocfel interpreter):

• .z3, .z4, .z5, .z7, .z8 - Z-code game files
• .zblorb - Blorb containers with Z-machine games

Find games at the IF Archive: Glulx games, Z-code games.

Journaling Mode

Enable with --require-journal or IF_REQUIRE_JOURNAL=true. In this mode:

1. After playing your first command, subsequent turns require a journal entry
2. Journal entries must be at least 100 words
3. Entries are saved to {game}/journal.jsonl
4. Use read_journal and search_journal to review your playthrough

This encourages thoughtful, reflective gameplay rather than rushing through.

How It Works

1. Games are stored in ~/.mcp-server-if/games/{name}/

2. Each game directory contains:

   • The game file (.ulx, .gblorb, .z5, etc.)
   • state/ - autosave data (persists between sessions)
   • metadata.json - session metadata
   • journal.jsonl - playthrough journal (if enabled)

3. The server selects the appropriate interpreter based on file format:

   • Glulx games → glulxe
   • Z-machine games → bocfel

4. Both interpreters use RemGlk for JSON-based I/O

5. Game state is automatically saved after each turn

Development

Requires uv, a C compiler (gcc or clang), a C++ compiler (g++ or clang++), make, and git.

git clone --recursive https://github.com/davidar/mcp-server-if.git
cd mcp-server-if
uv sync --group dev
uv run pytest -v

uv sync compiles the bundled interpreters (glulxe and bocfel) from source automatically. If binaries are missing after a fresh clone, run uv sync --reinstall-package mcp-server-if to force recompilation.

Troubleshooting

"glulxe binary not found"

This shouldn't happen with pip/uvx installs. If it does:

• Try reinstalling: pip install --force-reinstall mcp-server-if or uv sync --reinstall-package mcp-server-if
• Or set IF_GLULXE_PATH to a manually installed glulxe

"Game file not found"

Use list_games to see available games, or download_game to get new ones.

Save/restore commands don't work

In-game save/restore triggers file dialogs that aren't supported. Use the automatic autosave system instead - your game state persists between sessions automatically.

License

MIT License - see LICENSE for details.

Credits

• glulxe - The Glulx VM interpreter by Andrew Plotkin
• bocfel - Z-machine interpreter by Chris Spiegel
• RemGlk - Remote Glk library for JSON I/O
• MCP - Model Context Protocol by Anthropic