실습 2 — 클라이언트로 도구와 리소스 쓰기

import asyncio, json, os, sys
from mcp import ClientSession, StdioServerParameters
from mcp.client.stdio import stdio_client

PARAMS = StdioServerParameters(command=sys.executable, args=["out_stock_server.py"])     # 실습 1에서 만든 서버

async def main():
    async with stdio_client(PARAMS, errlog=open(os.devnull, "w")) as (read, write):
        async with ClientSession(read, write) as session:
            await session.initialize()
            r = await session.call_tool("get_stock", {"code": "T-201"})        # tools/call
            print("오류인가:", r.is_error, "· 내용 조각 수:", len(r.content))
            print(r.content[0].text)
            res = await session.read_resource("stock://warehouses")             # resources/read
            print("창고:", res.contents[0].text)

asyncio.run(main())

async def errors():
    async with stdio_client(PARAMS, errlog=open(os.devnull, "w")) as (read, write):
        async with ClientSession(read, write) as session:
            await session.initialize()
            for name, args in [("get_stock", {"code": "X-999"}),        # 없는 코드: 도구가 오류 결과를 돌려준다
                               ("get_stock", {}),                       # 필수 인자 빠짐
                               ("no_such_tool", {"code": "P-101"})]:    # 없는 도구
                try:
                    r = await session.call_tool(name, args)
                    print(f"{name} {args} → is_error={r.is_error} · {r.content[0].text[:60]!r}")
                except Exception as e:
                    print(f"{name} {args} → 예외 {type(e).__name__}: {str(e)[:60]}")

asyncio.run(errors())

async def low_items():
    """모든 품목을 받아 창고별로 최소수량보다 적은 것을 고른다(도구 결과를 코드가 쓰는 예)"""
    async with stdio_client(PARAMS, errlog=open(os.devnull, "w")) as (read, write):
        async with ClientSession(read, write) as session:
            await session.initialize()
            items = json.loads((await session.call_tool("list_items", {})).content[0].text)["품목"]
            low = []
            for it in items:
                info = json.loads((await session.call_tool("get_stock", {"code": it["코드"]})).content[0].text)
                low += [(it["코드"], it["품목"], w["창고"], w["수량"]) for w in info["창고별"] if w["수량"] < w["최소수량"]]
            return len(items), low

n, low = asyncio.run(low_items())
print("품목", n, "개 가운데 모자란 것:")
for row in low:
    print(" ", row)