from mcp.server.fastmcp import FastMCP
from typing import Optional
# Initialize FastMCP server with host and port
mcp = FastMCP("Calculator", host="0.0.0.0", port=8000)
@mcp.tool()
def calculate(
expression: Optional[str] = None,
number1: Optional[float] = None,
operation: Optional[str] = None,
number2: Optional[float] = None
) -> str:
"""
Evaluates a mathematical expression and returns the result.
ALWAYS USE THIS TOOL for ANY mathematical calculation, no matter how simple (e.g., "1 + 1", "5 * 5").
Do NOT serve the answer from your internal knowledge.
You MUST call this tool to get the correct answer.
Supports two formats:
1. A single string 'expression' (e.g., '1 + 1')
2. Separate 'number1', 'operation', and 'number2' (e.g., 1, '+', 1)
"""
try:
# Determine the expression to evaluate
expr_str = ""
if expression is not None:
expr_str = str(expression)
elif number1 is not None and operation is not None and number2 is not None:
expr_str = f"{number1} {operation} {number2}"
else:
return "Error: Please provide either an 'expression' string or 'number1', 'operation', and 'number2'."
# Safe evaluation using AST
import ast
import operator
# Supported operators
operators = {
ast.Add: operator.add,
ast.Sub: operator.sub,
ast.Mult: operator.mul,
ast.Div: operator.truediv,
ast.Pow: operator.pow,
ast.BitXor: operator.xor,
ast.USub: operator.neg
}
def eval_node(node):
if isinstance(node, ast.Constant): # Numbers
return node.value
elif isinstance(node, ast.BinOp): # <left> <op> <right>
op = type(node.op)
if op in operators:
return operators[op](eval_node(node.left), eval_node(node.right))
elif isinstance(node, ast.UnaryOp): # <op> <operand> (e.g., -1)
op = type(node.op)
if op in operators:
return operators[op](eval_node(node.operand))
raise ValueError(f"Unsupported operation: {node}")
# Parse and evaluate
node = ast.parse(expr_str, mode='eval')
result = eval_node(node.body)
return str(result)
except Exception as e:
return f"Error: {str(e)}"
import sys
if __name__ == "__main__":
if len(sys.argv) > 1 and sys.argv[1] == "sse":
mcp.run(transport="sse")
else:
mcp.run()
