#!/usr/bin/env python3
"""
MCP Reference: Minimal Server
==============================
The simplest possible MCP server demonstrating the bare minimum requirements.
MCP Spec Version: 2025-06-18
Features Demonstrated:
- Initialize/lifecycle
- Single tool definition
- Basic JSON-RPC handling
Spec References:
- Lifecycle: https://modelcontextprotocol.io/specification/2025-06-18/basic/lifecycle
- Tools: https://modelcontextprotocol.io/specification/2025-06-18/server/tools
"""
from chuk_mcp_server import ChukMCPServer
# Create server instance
# chuk-mcp-server handles all protocol implementation
mcp = ChukMCPServer(
name="minimal-mcp-server",
version="1.0.0",
)
# ============================================================================
# MCP Spec: tools/call
# Defines a single tool that the LLM can invoke
# ============================================================================
@mcp.tool
def hello(name: str = "World") -> str:
"""
Say hello to someone.
This demonstrates the minimum viable tool:
- Has a name (function name)
- Has a description (docstring)
- Has parameters with types (name: str)
- Returns a value
Args:
name: Name of the person to greet
Returns:
A greeting message
"""
return f"Hello, {name}!"
# ============================================================================
# Server Execution
# ============================================================================
def main() -> None:
"""Run the minimal MCP server."""
print("🚀 Minimal MCP Reference Server")
print("=" * 50)
print(f"Server: {mcp.server_info.name}")
print(f"Version: {mcp.server_info.version}")
print()
print("Features:")
print(" ✅ Lifecycle (initialize, ping)")
print(" ✅ Tools (1 tool: hello)")
print()
print("MCP Spec: 2025-06-18")
print("=" * 50)
print()
print("Running on http://localhost:8000")
print("MCP endpoint: http://localhost:8000/mcp")
print()
print("Test with MCP Inspector:")
print(" npx @modelcontextprotocol/inspector")
print()
# Run server - chuk-mcp-server handles:
# - JSON-RPC 2.0 protocol
# - initialize/initialized handshake
# - tools/list request
# - tools/call request
# - ping request
# - All error handling
mcp.run(host="localhost", port=8000)
if __name__ == "__main__":
main()
