Merge pull request #444 from microsoft/calfix

Calfix

Author: leestott

03-GettingStarted/samples/python/README.md

@@ -1,48 +1,54 @@
-# Sample
-
-This is a Python sample for an MCP Server
-
-Here's what the calculator portion looks like:
-
-```python
-@mcp.tool()
-def add(a: float, b: float) -> float:
-    """Add two numbers together and return the result."""
-    return a + b
-
-@mcp.tool()
-def subtract(a: float, b: float) -> float:
-    """Subtract b from a and return the result."""
-    return a - b
-
-@mcp.tool()
-def multiply(a: float, b: float) -> float:
-    """Multiply two numbers together and return the result."""
-    return a * b
-
-@mcp.tool()
-def divide(a: float, b: float) -> float:
-    """
-    Divide a by b and return the result.
-    
-    Raises:
-        ValueError: If b is zero
-    """
-    if b == 0:
-        raise ValueError("Cannot divide by zero")
-    return a / b
-```
+# MCP Calculator Server (Python)
+
+
+
+A simple Model Context Protocol (MCP) server implementation in Python that provides basic calculator functionality.
 
-## Install
 
-Run the following command:
+## Installation
+
+Install the required dependencies:
 
 ```bash
-pip install mcp
+pip install -r requirements.txt
 ```
 
-## Run
+Or install the MCP Python SDK directly:
+
+```bash
+pip install mcp>=1.18.0
+```
+
+## Usage
+
+### Running the Server
+
+The server is designed to be used by MCP clients (like Claude Desktop). To start the server:
 
 ```bash
 python mcp_calculator_server.py
-```
+```
+
+**Note**: When run directly in a terminal, you'll see JSON-RPC validation errors. This is normal behavior - the server is waiting for properly formatted MCP client messages.
+
+### Testing the Functions
+
+To test that the calculator functions work correctly:
+
+```bash
+python test_calculator.py
+```
+
+## Troubleshooting
+
+### Import Errors
+
+If you see `ModuleNotFoundError: No module named 'mcp'`, install the MCP Python SDK:
+
+```bash
+pip install mcp>=1.18.0
+```
+
+### JSON-RPC Errors When Running Directly
+
+Errors like "Invalid JSON: EOF while parsing a value" when running the server directly are expected. The server needs MCP client messages, not direct terminal input.

03-GettingStarted/samples/python/mcp_calculator_server.py

@@ -6,15 +6,10 @@
 that can perform basic arithmetic operations (add, subtract, multiply, divide).
 """
 
-import asyncio
 from mcp.server.fastmcp import FastMCP
-from mcp.server.transports.stdio import serve_stdio
 
 # Create a FastMCP server
-mcp = FastMCP(
-    name="Calculator MCP Server",
-    version="1.0.0"
-)
+mcp = FastMCP("Calculator MCP Server")
 
 @mcp.tool()
 def add(a: float, b: float) -> float:
@@ -44,5 +39,5 @@ def divide(a: float, b: float) -> float:
     return a / b
 
 if __name__ == "__main__":
-    # Start the server with stdio transport
-    asyncio.run(serve_stdio(mcp))
+    # Start the server
+    mcp.run()

03-GettingStarted/samples/python/requirements.txt

@@ -0,0 +1 @@
+mcp>=1.18.0

03-GettingStarted/samples/python/test_calculator.py

@@ -0,0 +1,53 @@
+#!/usr/bin/env python3
+"""
+Test script for the MCP Calculator Server.
+
+This script tests the calculator functions to ensure they work correctly
+before running the MCP server.
+"""
+
+import sys
+import os
+
+# Add the current directory to the path so we can import the calculator server
+sys.path.insert(0, os.path.dirname(os.path.abspath(__file__)))
+
+def test_calculator_functions():
+    """Test all calculator functions."""
+    # Import the functions from the calculator server
+    from mcp_calculator_server import add, subtract, multiply, divide
+    
+    print("Testing calculator functions...")
+    
+    # Test addition
+    result = add(5, 3)
+    assert result == 8, f"Expected 8, got {result}"
+    print("✓ Addition test passed")
+    
+    # Test subtraction
+    result = subtract(10, 4)
+    assert result == 6, f"Expected 6, got {result}"
+    print("✓ Subtraction test passed")
+    
+    # Test multiplication
+    result = multiply(7, 6)
+    assert result == 42, f"Expected 42, got {result}"
+    print("✓ Multiplication test passed")
+    
+    # Test division
+    result = divide(15, 3)
+    assert result == 5, f"Expected 5, got {result}"
+    print("✓ Division test passed")
+    
+    # Test division by zero
+    try:
+        divide(10, 0)
+        assert False, "Expected ValueError for division by zero"
+    except ValueError as e:
+        assert str(e) == "Cannot divide by zero", f"Expected 'Cannot divide by zero', got '{str(e)}'"
+        print("✓ Division by zero test passed")
+    
+    print("\nAll calculator function tests passed! ✅")
+
+if __name__ == "__main__":
+    test_calculator_functions()