"""
Minimal Hello World MCP Server Example
To test this server, use prompts like:
- "test MCP"
- "say hello"
- "are you working?"
"""
#region imports
import asyncio # For async/await functionality
# Required imports for MCP server functionality
import mcp.server.stdio
from mcp.server import Server, NotificationOptions
from mcp.server.models import InitializationOptions
from mcp.types import Tool, TextContent
#endregion
#region variables
# Create a new MCP server instance with a name
server = Server("helloworld_server")
#endregion
#region MCP functions
## Define what tools are available to the LLM
@server.list_tools()
async def list_tools():
# Return a list of available tools
return [
Tool(
# Tool identifier; what it does. This is used by the LLM to find/call the tool.
name="say_hello",
description=(
"Says hello to demonstrate MCP is working."
"Use when user wants to test the connection or asks for a greeting."
"Example: 'test MCP', 'say hello', 'are you working?'"
),
# Define expected input parameters
inputSchema={
"type": "object", # No properties needed
"properties": {},
"required": [], # No required parameters
},
)
]
## Handle tool execution requests from the LLM
@server.call_tool()
async def call_tool(name, arguments):
# Check which tool was requested
if name == "say_hello":
# Return the hello world message
return [TextContent(type="text", text="Hello World! MCP server is working!")]
# Return error if unknown tool requested
return [TextContent(type="text", text=f"Unknown tool: {name}")]
#endregion
#region functions
## Main entry point
async def main():
# Use the stdio_server context manager to get read/write streams
async with mcp.server.stdio.stdio_server() as (read_stream, write_stream):
# Run the server with streams and initialization options as positional arguments
await server.run(
read_stream,
write_stream,
InitializationOptions(
server_name="helloworld_server",
server_version="0.1.0",
capabilities=server.get_capabilities(
notification_options=NotificationOptions(),
experimental_capabilities={}
)
),
)
# Run the server when script is executed directly
if __name__ == "__main__":
asyncio.run(main())
#endregion
