agent-Specialization/scripts/mcp_demo_server.py

141 lines
4.0 KiB
Python

#!/usr/bin/env python3
"""最小可运行 MCP stdio 示例服务。
功能:
- tools/list: 返回 echo_upper / add_numbers 两个工具
- tools/call: 执行对应逻辑并返回 text + structuredContent
"""
from __future__ import annotations
import json
import sys
from typing import Any, Dict
PROTOCOL_VERSION = "2025-06-18"
def _send(payload: Dict[str, Any]) -> None:
sys.stdout.write(json.dumps(payload, ensure_ascii=False) + "\n")
sys.stdout.flush()
def _ok(msg_id: Any, result: Dict[str, Any]) -> None:
_send({"jsonrpc": "2.0", "id": msg_id, "result": result})
def _err(msg_id: Any, code: int, message: str) -> None:
_send({"jsonrpc": "2.0", "id": msg_id, "error": {"code": code, "message": message}})
def _tools_list() -> Dict[str, Any]:
return {
"tools": [
{
"name": "echo_upper",
"description": "将 text 转为大写后返回",
"inputSchema": {
"type": "object",
"properties": {"text": {"type": "string", "description": "输入文本"}},
"required": ["text"],
},
},
{
"name": "add_numbers",
"description": "计算两个数字相加",
"inputSchema": {
"type": "object",
"properties": {
"a": {"type": "number", "description": "加数A"},
"b": {"type": "number", "description": "加数B"},
},
"required": ["a", "b"],
},
},
]
}
def _call_tool(name: str, arguments: Dict[str, Any]) -> Dict[str, Any]:
if name == "echo_upper":
text = str((arguments or {}).get("text") or "")
result = text.upper()
return {
"isError": False,
"content": [{"type": "text", "text": result}],
"structuredContent": {"result": result},
}
if name == "add_numbers":
try:
a = float((arguments or {}).get("a"))
b = float((arguments or {}).get("b"))
except Exception:
return {
"isError": True,
"content": [{"type": "text", "text": "参数 a/b 必须是数字"}],
"structuredContent": {"error": "invalid_arguments"},
}
value = a + b
return {
"isError": False,
"content": [{"type": "text", "text": f"{a} + {b} = {value}"}],
"structuredContent": {"a": a, "b": b, "sum": value},
}
return {
"isError": True,
"content": [{"type": "text", "text": f"未知工具: {name}"}],
"structuredContent": {"error": "tool_not_found", "name": name},
}
def main() -> int:
while True:
line = sys.stdin.readline()
if not line:
break
line = line.strip()
if not line:
continue
try:
req = json.loads(line)
except Exception:
continue
method = req.get("method")
msg_id = req.get("id")
params = req.get("params") or {}
# 通知无需响应
if msg_id is None:
continue
if method == "initialize":
_ok(
msg_id,
{
"protocolVersion": PROTOCOL_VERSION,
"capabilities": {"tools": {"listChanged": False}},
"serverInfo": {"name": "demo-stdio-mcp", "version": "1.0.0"},
},
)
continue
if method == "tools/list":
_ok(msg_id, _tools_list())
continue
if method == "tools/call":
name = str(params.get("name") or "").strip()
arguments = params.get("arguments") if isinstance(params.get("arguments"), dict) else {}
_ok(msg_id, _call_tool(name, arguments))
continue
_err(msg_id, -32601, f"Method not found: {method}")
return 0
if __name__ == "__main__":
raise SystemExit(main())