Dice Roller MCP Server

#!/usr/bin/env python3 """ Simple Dice Roller MCP Server - Provides comprehensive dice rolling functionality for games and simulations """ import os import sys import logging import random from mcp.server.fastmcp import FastMCP # Configure logging to stderr logging.basicConfig( level=logging.INFO, format='%(asctime)s - %(name)s - %(levelname)s - %(message)s', stream=sys.stderr ) logger = logging.getLogger("dice-server") # Initialize MCP server - NO PROMPT PARAMETER! mcp = FastMCP("dice") # === UTILITY FUNCTIONS === def parse_dice_notation(notation): """Parse dice notation like 2d6+3 into components""" try: # Handle modifier modifier = 0 if '+' in notation: parts = notation.split('+') notation = parts[0] modifier = int(parts[1]) elif '-' in notation: parts = notation.split('-') notation = parts[0] modifier = -int(parts[1]) # Parse XdY format if 'd' in notation.lower(): parts = notation.lower().split('d') num_dice = int(parts[0]) if parts[0] else 1 sides = int(parts[1]) return num_dice, sides, modifier else: # Single number means 1 die with that many sides return 1, int(notation), modifier except: return None, None, None def format_roll_result(rolls, total, modifier=0): """Format roll results nicely""" if len(rolls) == 1 and modifier == 0: return f"🎲 Rolled: {rolls[0]}" rolls_str = " + ".join(str(r) for r in rolls) if modifier > 0: return f"🎲 Rolled: {rolls_str} + {modifier} = **{total}**" elif modifier < 0: return f"🎲 Rolled: {rolls_str} - {abs(modifier)} = **{total}**" else: return f"🎲 Rolled: {rolls_str} = **{total}**" # === MCP TOOLS === @mcp.tool() async def flip_coin(count: str = "1") -> str: """Flip one or more coins and show results as heads or tails.""" logger.info(f"Flipping {count} coin(s)") try: num_coins = int(count) if count.strip() else 1 if num_coins < 1: return "❌ Error: Must flip at least 1 coin" if num_coins > 100: return "❌ Error: Maximum 100 coins at once" results = [] for _ in range(num_coins): results.append("Heads" if random.randint(0, 1) == 1 else "Tails") if num_coins == 1: return f"🪙 Coin flip: **{results[0]}**" else: heads = results.count("Heads") tails = results.count("Tails") return f"""🪙 Flipped {num_coins} coins: - Heads: {heads} ({heads/num_coins*100:.1f}%) - Tails: {tails} ({tails/num_coins*100:.1f}%) Results: {', '.join(results)}""" except ValueError: return f"❌ Error: Invalid count: {count}" except Exception as e: logger.error(f"Error: {e}") return f"❌ Error: {str(e)}" @mcp.tool() async def roll_dice(notation: str = "1d20") -> str: """Roll dice using standard notation like 1d20, 2d6+3, 3d8-2, etc.""" logger.info(f"Rolling dice: {notation}") try: if not notation.strip(): notation = "1d20" num_dice, sides, modifier = parse_dice_notation(notation) if num_dice is None: return f"❌ Error: Invalid dice notation '{notation}'. Use format like '2d6' or '1d20+5'" if num_dice < 1 or num_dice > 100: return "❌ Error: Number of dice must be between 1 and 100" if sides < 2 or sides > 1000: return "❌ Error: Dice sides must be between 2 and 1000" rolls = [random.randint(1, sides) for _ in range(num_dice)] total = sum(rolls) + modifier result = format_roll_result(rolls, total, modifier) return result except Exception as e: logger.error(f"Error: {e}") return f"❌ Error: {str(e)}" @mcp.tool() async def roll_custom(sides: str = "6", count: str = "1") -> str: """Roll custom dice with any number of sides.""" logger.info(f"Rolling {count} d{sides}") try: num_sides = int(sides) if sides.strip() else 6 num_dice = int(count) if count.strip() else 1 if num_dice < 1 or num_dice > 100: return "❌ Error: Number of dice must be between 1 and 100" if num_sides < 2 or num_sides > 1000: return "❌ Error: Dice sides must be between 2 and 1000" rolls = [random.randint(1, num_sides) for _ in range(num_dice)] total = sum(rolls) result = f"🎲 Rolling {num_dice}d{num_sides}: " if num_dice == 1: result += f"**{rolls[0]}**" else: result += f"{' + '.join(str(r) for r in rolls)} = **{total}**" return result except ValueError: return f"❌ Error: Invalid input - sides: {sides}, count: {count}" except Exception as e: logger.error(f"Error: {e}") return f"❌ Error: {str(e)}" @mcp.tool() async def roll_stats() -> str: """Roll D&D ability scores using 4d6 drop lowest method for all six stats.""" logger.info("Rolling D&D stats") try: stats = [] details = [] for i in range(6): rolls = sorted([random.randint(1, 6) for _ in range(4)], reverse=True) kept = rolls[:3] dropped = rolls[3] stat_total = sum(kept) stats.append(stat_total) details.append(f" {i+1}. Rolled: {rolls} → Kept {kept} (dropped {dropped}) = **{stat_total}**") stats_sorted = sorted(stats, reverse=True) total = sum(stats) modifier_total = sum((stat - 10) // 2 for stat in stats) return f"""⚔️ **D&D Ability Scores** (4d6 drop lowest): {chr(10).join(details)} **Final Stats:** {', '.join(str(s) for s in stats)} **Sorted:** {', '.join(str(s) for s in stats_sorted)} **Total:** {total} | **Modifier Sum:** {'+' if modifier_total >= 0 else ''}{modifier_total}""" except Exception as e: logger.error(f"Error: {e}") return f"❌ Error: {str(e)}" @mcp.tool() async def roll_advantage(modifier: str = "0") -> str: """Roll a d20 with advantage (roll twice, take higher) with optional modifier.""" logger.info(f"Rolling with advantage, modifier: {modifier}") try: mod = int(modifier) if modifier.strip() else 0 roll1 = random.randint(1, 20) roll2 = random.randint(1, 20) higher = max(roll1, roll2) total = higher + mod result = f"🎯 **Advantage Roll:**\n" result += f" First roll: {roll1}\n" result += f" Second roll: {roll2}\n" result += f" Taking higher: **{higher}**" if mod != 0: result += f"\n With modifier: {higher} {'+' if mod >= 0 else '-'} {abs(mod)} = **{total}**" if roll1 == 20 or roll2 == 20: result += "\n 🌟 **CRITICAL SUCCESS!**" elif roll1 == 1 and roll2 == 1: result += "\n 💀 **CRITICAL FAILURE!**" return result except ValueError: return f"❌ Error: Invalid modifier: {modifier}" except Exception as e: logger.error(f"Error: {e}") return f"❌ Error: {str(e)}" @mcp.tool() async def roll_disadvantage(modifier: str = "0") -> str: """Roll a d20 with disadvantage (roll twice, take lower) with optional modifier.""" logger.info(f"Rolling with disadvantage, modifier: {modifier}") try: mod = int(modifier) if modifier.strip() else 0 roll1 = random.randint(1, 20) roll2 = random.randint(1, 20) lower = min(roll1, roll2) total = lower + mod result = f"😰 **Disadvantage Roll:**\n" result += f" First roll: {roll1}\n" result += f" Second roll: {roll2}\n" result += f" Taking lower: **{lower}**" if mod != 0: result += f"\n With modifier: {lower} {'+' if mod >= 0 else '-'} {abs(mod)} = **{total}**" if lower == 20: result += "\n 🌟 **CRITICAL SUCCESS!**" elif lower == 1: result += "\n 💀 **CRITICAL FAILURE!**" return result except ValueError: return f"❌ Error: Invalid modifier: {modifier}" except Exception as e: logger.error(f"Error: {e}") return f"❌ Error: {str(e)}" @mcp.tool() async def roll_check(dc: str = "15", modifier: str = "0", skill_name: str = "") -> str: """Make a skill check against a DC with a d20 roll plus modifier.""" logger.info(f"Rolling skill check DC {dc} with modifier {modifier}") try: difficulty_class = int(dc) if dc.strip() else 15 mod = int(modifier) if modifier.strip() else 0 skill = skill_name.strip() if skill_name.strip() else "Check" roll = random.randint(1, 20) total = roll + mod success = total >= difficulty_class result = f"🎲 **{skill} (DC {difficulty_class}):**\n" result += f" Rolled: {roll}" if mod != 0: result += f" {'+' if mod >= 0 else '-'} {abs(mod)} = **{total}**" else: result += f" = **{total}**" if roll == 20: result += "\n 🌟 **NATURAL 20! CRITICAL SUCCESS!**" elif roll == 1: result += "\n 💀 **NATURAL 1! CRITICAL FAILURE!**" elif success: margin = total - difficulty_class result += f"\n ✅ **SUCCESS!** (by {margin} point{'s' if margin != 1 else ''})" else: margin = difficulty_class - total result += f"\n ❌ **FAILURE** (missed by {margin} point{'s' if margin != 1 else ''})" return result except ValueError: return f"❌ Error: Invalid input - DC: {dc}, modifier: {modifier}" except Exception as e: logger.error(f"Error: {e}") return f"❌ Error: {str(e)}" @mcp.tool() async def roll_initiative(modifier: str = "0", combatants: str = "1") -> str: """Roll initiative for one or more combatants in D&D combat.""" logger.info(f"Rolling initiative for {combatants} combatants") try: mod = int(modifier) if modifier.strip() else 0 num_combatants = int(combatants) if combatants.strip() else 1 if num_combatants < 1 or num_combatants > 20: return "❌ Error: Number of combatants must be between 1 and 20" results = [] for i in range(num_combatants): roll = random.randint(1, 20) total = roll + mod results.append((i + 1, roll, total)) # Sort by total initiative (descending) results.sort(key=lambda x: x[2], reverse=True) output = "⚔️ **Initiative Order:**\n" for combatant, roll, total in results: if num_combatants == 1: output += f" Rolled: {roll}" if mod != 0: output += f" {'+' if mod >= 0 else '-'} {abs(mod)}" output += f" = **{total}**" else: output += f" Combatant {combatant}: {roll}" if mod != 0: output += f" {'+' if mod >= 0 else '-'} {abs(mod)}" output += f" = **{total}**\n" return output.rstrip() except ValueError: return f"❌ Error: Invalid input - modifier: {modifier}, combatants: {combatants}" except Exception as e: logger.error(f"Error: {e}") return f"❌ Error: {str(e)}" # === SERVER STARTUP === if __name__ == "__main__": logger.info("Starting Dice Roller MCP server...") try: mcp.run(transport='stdio') except Exception as e: logger.error(f"Server error: {e}", exc_info=True) sys.exit(1)