advanced_calculator_server.py•13.2 kB
#!/usr/bin/env python
import re
from typing import Dict, List, Any, Optional, Union
import math
from mcp.server.fastmcp import FastMCP
# 创建MCP服务器实例
mcp = FastMCP("高级计算器(Advanced Calculator)")
# 存储计算历史
calculation_history = []
@mcp.tool()
def add(a: float, b: float) -> float:
"""
将两个数相加
Add two numbers.
参数(Parameters):
a: 第一个数 (First number)
b: 第二个数 (Second number)
返回(Return):
两个数的和 (Sum of the two numbers)
"""
result = a + b
save_calculation("add", a, b, result)
return result
@mcp.tool()
def subtract(a: float, b: float) -> float:
"""
从第一个数中减去第二个数
Subtract the second number from the first number.
参数(Parameters):
a: 第一个数 (First number)
b: 第二个数 (Second number)
返回(Return):
两个数的差 (Difference of the two numbers)
"""
result = a - b
save_calculation("subtract", a, b, result)
return result
@mcp.tool()
def multiply(a: float, b: float) -> float:
"""
将两个数相乘
Multiply two numbers.
参数(Parameters):
a: 第一个数 (First number)
b: 第二个数 (Second number)
返回(Return):
两个数的积 (Product of the two numbers)
"""
result = a * b
save_calculation("multiply", a, b, result)
return result
@mcp.tool()
def divide(a: float, b: float) -> float:
"""
将第一个数除以第二个数
Divide the first number by the second number.
参数(Parameters):
a: 被除数 (Dividend)
b: 除数 (Divisor)
返回(Return):
两个数的商 (Quotient of the two numbers)
抛出(Raises):
ValueError: 当除数为0时 (When divisor is zero)
"""
if b == 0:
raise ValueError("除数不能为0(Divisor cannot be zero)")
result = a / b
save_calculation("divide", a, b, result)
return result
@mcp.tool()
def power(base: float, exponent: float) -> float:
"""
计算一个数的幂
Calculate the power of a number.
参数(Parameters):
base: 底数 (Base)
exponent: 指数 (Exponent)
返回(Return):
底数的指数次幂 (Base raised to the power of exponent)
"""
result = math.pow(base, exponent)
save_to_history({
"operation": "power",
"base": base,
"exponent": exponent,
"result": result
})
return result
@mcp.tool()
def sqrt(value: float) -> float:
"""
计算一个数的平方根
Calculate the square root of a number.
参数(Parameters):
value: 要计算平方根的数 (The number to calculate the square root of)
返回(Return):
输入值的平方根 (Square root of the input value)
抛出(Raises):
ValueError: 当输入为负数时 (When input is negative)
"""
if value < 0:
raise ValueError("不能计算负数的平方根")
result = math.sqrt(value)
save_to_history({
"operation": "sqrt",
"value": value,
"result": result
})
return result
@mcp.tool()
def evaluate_expression(expression: str) -> float:
"""
计算数学表达式
Evaluate a mathematical expression.
参数(Parameters):
expression: 要计算的数学表达式字符串 (The mathematical expression string to evaluate)
返回(Return):
表达式计算结果 (Result of the evaluated expression)
抛出(Raises):
ValueError: 当表达式无效或包含不安全代码时 (When the expression is invalid or contains unsafe code)
"""
# 保存原始表达式用于显示
original_expression = expression
# 替换常见的数学常量（在安全检查之前）
expression = expression.replace("pi", str(math.pi))
expression = expression.replace("e", str(math.e))
# 安全检查 - 只允许基本的数学表达式
if not is_safe_expression(expression):
raise ValueError("无效或不安全的表达式(Invalid or unsafe expression)")
# 计算表达式
try:
# 注意: 这里使用了eval()，但我们已经在is_safe_expression()中进行了安全检查
result = eval(expression, {"__builtins__": {}}, math_globals())
save_to_history({
"operation": "evaluate",
"expression": original_expression, # 保存原始表达式用于显示
"result": result
})
return result
except Exception as e:
raise ValueError(f"计算表达式时出错: {str(e)}(Error evaluating expression: {str(e)})")
def is_safe_expression(expression: str) -> bool:
"""检查表达式是否安全，只允许基本的数学运算符和函数(Check if the expression is safe, only allow basic mathematical operators and functions)"""
# 保存原始表达式用于危险模式检查
original_expression = expression
# 替换数学常量后的表达式
temp_expression = expression.replace("pi", str(math.pi)).replace("e", str(math.e))
# 允许数字、运算符、小数点、空格、括号、基本数学符号和字母（用于pi和e以及函数名）
allowed_pattern = r'^[\d\s\+\-\*\/\(\)\.\,\%\^a-zA-Z_]+$'
# 检查原始表达式是否包含允许的字符
if not re.match(allowed_pattern, original_expression):
return False
# 定义允许的数学函数
allowed_functions = {
'sin', 'cos', 'tan', 'asin', 'acos', 'atan', 'atan2',
'sinh', 'cosh', 'tanh', 'log', 'log10', 'ln', 'exp',
'sqrt', 'abs', 'pow', 'ceil', 'floor', 'fabs', 'fmod',
'degrees', 'radians', 'hypot'
}
# 检查函数调用
function_calls = re.findall(r'([a-zA-Z_][a-zA-Z0-9_]*)\s*\(', original_expression)
for func_name in function_calls:
if func_name.lower() not in allowed_functions:
return False
# 检查是否只包含允许的数学常量（除了函数名）
temp_for_constants = original_expression
# 移除函数调用
temp_for_constants = re.sub(r'[a-zA-Z_][a-zA-Z0-9_]*\s*\(', '(', temp_for_constants)
# 移除数学常量
for const in ['pi', 'e']:
temp_for_constants = temp_for_constants.replace(const, '')
# 剩下的应该只包含数字和基本运算符
basic_pattern = r'^[\d\s\+\-\*\/\(\)\.\,\%\^]+$'
if not re.match(basic_pattern, temp_for_constants):
return False
# 额外的安全检查：确保不包含危险的模式
dangerous_patterns = [
r'__\w+__', # 防止访问特殊方法
r'import\s+', # 防止import语句
r'exec\s*\(', # 防止exec调用
r'eval\s*\(', # 防止嵌套eval调用
r'open\s*\(', # 防止文件操作
r'input\s*\(', # 防止输入函数
r'print\s*\(', # 防止print函数
r'file\s*\(', # 防止文件操作
]
for pattern in dangerous_patterns:
if re.search(pattern, original_expression, re.IGNORECASE):
return False
return True
def math_globals() -> Dict[str, Any]:
"""创建用于表达式计算的安全数学函数全局字典"""
safe_list = [
'math', 'acos', 'asin', 'atan', 'atan2', 'ceil', 'cos',
'cosh', 'degrees', 'e', 'exp', 'fabs', 'floor', 'fmod',
'frexp', 'hypot', 'ldexp', 'log', 'log10', 'modf', 'pi',
'pow', 'radians', 'sin', 'sinh', 'sqrt', 'tan', 'tanh'
]
safe_dict = {}
for k in safe_list:
if hasattr(math, k):
safe_dict[k] = getattr(math, k)
# 添加一些常量和别名
safe_dict['pi'] = math.pi
safe_dict['e'] = math.e
safe_dict['ln'] = math.log # 自然对数别名
safe_dict['abs'] = abs # 绝对值函数
return safe_dict
def save_calculation(operation: str, a: float, b: float, result: float) -> None:
"""保存基本计算到历史记录(Save basic calculation to history)"""
save_to_history({
"operation": operation,
"a": a,
"b": b,
"result": result
})
def save_to_history(data: Dict[str, Any]) -> None:
"""将计算保存到历史记录并发送通知(Save calculation to history and send notification)"""
calculation_history.append(data)
# 最多保存最近的20条历史记录
if len(calculation_history) > 20:
calculation_history.pop(0)
# 发送资源更新通知（如果支持的话）
if hasattr(mcp, 'notify_resource_changed'):
mcp.notify_resource_changed("calculator://history")
@mcp.resource("calculator://help")
def help_resource() -> str:
"""
提供计算器帮助信息
Provide help information for the calculator.
返回(Return):
帮助信息字符串 (Help information string)
"""
return """
高级计算器 MCP 服务器
基本运算工具:
- add(a, b): 计算 a + b
- subtract(a, b): 计算 a - b
- multiply(a, b): 计算 a * b
- divide(a, b): 计算 a / b (注意: b不能为0)
高级运算工具:
- power(base, exponent): 计算 base 的 exponent 次幂
- sqrt(value): 计算平方根
- evaluate_expression(expression): 计算数学表达式字符串
可用的资源:
- calculator://help: 这个帮助信息
- calculator://history: 最近的计算历史
"""
@mcp.resource("calculator://history")
def history_resource() -> str:
"""
获取计算历史
Get calculation history.
返回(Return):
最近的计算历史字符串 (Recent calculation history string)
"""
if not calculation_history:
return "暂无计算历史(No calculation history)"
history_text = "计算历史(Calculation history):\n"
for i, calc in enumerate(calculation_history, 1):
op = calc["operation"]
if op in ["add", "subtract", "multiply", "divide"]:
a = calc["a"]
b = calc["b"]
result = calc["result"]
op_symbols = {
"add": "+",
"subtract": "-",
"multiply": "*",
"divide": "/"
}
op_symbol = op_symbols.get(op, op)
history_text += f"{i}. {a} {op_symbol} {b} = {result}\n"
elif op == "power":
base = calc["base"]
exponent = calc["exponent"]
result = calc["result"]
history_text += f"{i}. {base}^{exponent} = {result}\n"
elif op == "sqrt":
value = calc["value"]
result = calc["result"]
history_text += f"{i}. √{value} = {result}\n"
elif op == "evaluate":
expression = calc["expression"]
result = calc["result"]
history_text += f"{i}. 表达式(Expression): {expression} = {result}\n"
return history_text
@mcp.prompt()
def calculate_prompt(operation: str, a: Optional[float] = None, b: Optional[float] = None, expression: Optional[str] = None) -> str:
"""
创建一个计算提示
Create a calculation prompt.
参数(Parameters):
operation: 操作类型 (Operation type: add, subtract, multiply, divide, power, sqrt, evaluate)
a: 第一个数 (First number, for basic operations)
b: 第二个数 (Second number, for basic operations)
expression: 表达式 (Expression, for evaluate operation)
返回(Return):
计算提示字符串 (Calculation prompt string)
"""
if operation == "evaluate" and expression:
return f"请计算表达式: {expression}(Please calculate the expression: {expression})"
if operation in ["add", "subtract", "multiply", "divide"] and a is not None and b is not None:
operations = {
"add": "加(Add)",
"subtract": "减(Subtract)",
"multiply": "乘(Multiply)",
"divide": "除(Divide)"
}
op_text = operations.get(operation, operation)
return f"请计算 {a} {op_text} {b} 的结果。(Please calculate the result of {a} {op_text} {b})"
if operation == "power" and a is not None and b is not None:
return f"请计算 {a} 的 {b} 次方。(Please calculate {a} to the power of {b})"
if operation == "sqrt" and a is not None:
return f"请计算 {a} 的平方根。(Please calculate the square root of {a})"
return "请指定有效的计算操作和参数。(Please specify a valid calculation operation and parameters)"
# 如果直接运行此文件，启动MCP服务器
if __name__ == "__main__":
mcp.run()