PyCraft (Python)

🐍 PyCraft

PyCraft is a lightweight utility mod that integrates a Python interpreter directly into the Minecraft client.

It is not designed to replace Java modding or create complex content mods. Instead, it serves as a flexible scripting tool to automate chat interactions, create custom keybindings, and execute expressions on the fly without restarting the game.

✨ Features

• Hot Reloading: The mod watches main.py in your mods folder. Changes are detected and reloaded automatically within 1 second.
• In-Game Console: Press Y to open a Python REPL console. You can run one-off expressions, test math, or call API functions directly from the game.
• Chat Interception: Hook into the chat stream to filter messages or trigger auto-responses.
• Input Handling: Bind Python logic to keyboard events (press, release, hold).
• GUI Automation: Open the chat window with pre-filled text (useful for command prefixes).

🚀 Getting Started

1. Install PyCraft (requires Fabric API).
2. Launch Minecraft.
3. The mod will automatically generate a main.py file in your .minecraft/mods/ folder.
4. Open main.py in any text editor (VS Code, Notepad++, etc.).
5. Write your code and save. The mod will reload it instantly.

📖 Scripting API

PyCraft runs on Jython (Python 2.7). You can use standard Python syntax and libraries.

Global Functions

These functions are available to call from your script or the in-game console:

Event Hooks

Define these functions in your main.py to handle game events:

onChat(message)

Called whenever a chat message is received by the client.

• message (str): The content of the chat message.

onKey(state, key, modifiers)

Called whenever a keyboard key is interacted with.

• state (int): The action type.
  • 0: Key Released (Unpress)
  • 1: Key Pressed
  • 2: Key Held (Long press)
• key (int): The GLFW key code (e.g., 85 is 'U').
• modifiers (int): Bitmask for modifier keys (Shift, Ctrl, Alt).

📝 Example: main.py

This example demonstrates how to create a "Global Chat" hotkey and a simple auto-responder.

# -*- coding: utf-8 -*-
import re

# Event: Key Input
def onKey(state, key, modifiers):
    # Check if key is 'U' (85) and action is Press (1)
    if key == 85 and state == 1: 
        # Open chat with '!' prefix for global chat
        openChat('!')

# Event: Chat Received
def onChat(message):
    # Search for "Hello" in the incoming message
    result = re.findall(u'Hello', message)
    
    # If found, reply automatically
    if (len(result) > 0):
        sendMessage('Hi')

print('PyCraft main.py loaded!')

⚠️ Technical Notes

• Python Version: This mod uses Jython 2.7. Python 3 features (like f-strings f"{var}" or async/await) are not supported.