49b9bb6724
Deploy Docs / deploy-docs (push) Failing after 1s
Conformance Tests / client-conformance (push) Failing after 3s
Conformance Tests / server-conformance (push) Failing after 1s
GitHub Actions Security Analysis / zizmor (push) Failing after 1s
CI / checks (push) Failing after 59m20s
CI / all-green (push) Waiting to run
103 lines
2.7 KiB
Python
103 lines
2.7 KiB
Python
"""Run from the repository root:
|
|
uv run examples/snippets/servers/lowlevel/lifespan.py
|
|
"""
|
|
|
|
from collections.abc import AsyncIterator
|
|
from contextlib import asynccontextmanager
|
|
from typing import TypedDict
|
|
|
|
import mcp_types as types
|
|
|
|
import mcp.server.stdio
|
|
from mcp.server import Server, ServerRequestContext
|
|
|
|
|
|
# Mock database class for example
|
|
class Database:
|
|
"""Mock database class for example."""
|
|
|
|
@classmethod
|
|
async def connect(cls) -> "Database":
|
|
"""Connect to database."""
|
|
print("Database connected")
|
|
return cls()
|
|
|
|
async def disconnect(self) -> None:
|
|
"""Disconnect from database."""
|
|
print("Database disconnected")
|
|
|
|
async def query(self, query_str: str) -> list[dict[str, str]]:
|
|
"""Execute a query."""
|
|
# Simulate database query
|
|
return [{"id": "1", "name": "Example", "query": query_str}]
|
|
|
|
|
|
class AppContext(TypedDict):
|
|
db: Database
|
|
|
|
|
|
@asynccontextmanager
|
|
async def server_lifespan(_server: Server[AppContext]) -> AsyncIterator[AppContext]:
|
|
"""Manage server startup and shutdown lifecycle."""
|
|
db = await Database.connect()
|
|
try:
|
|
yield {"db": db}
|
|
finally:
|
|
await db.disconnect()
|
|
|
|
|
|
async def handle_list_tools(
|
|
ctx: ServerRequestContext[AppContext], params: types.PaginatedRequestParams | None
|
|
) -> types.ListToolsResult:
|
|
"""List available tools."""
|
|
return types.ListToolsResult(
|
|
tools=[
|
|
types.Tool(
|
|
name="query_db",
|
|
description="Query the database",
|
|
input_schema={
|
|
"type": "object",
|
|
"properties": {"query": {"type": "string", "description": "SQL query to execute"}},
|
|
"required": ["query"],
|
|
},
|
|
)
|
|
]
|
|
)
|
|
|
|
|
|
async def handle_call_tool(
|
|
ctx: ServerRequestContext[AppContext], params: types.CallToolRequestParams
|
|
) -> types.CallToolResult:
|
|
"""Handle database query tool call."""
|
|
if params.name != "query_db":
|
|
raise ValueError(f"Unknown tool: {params.name}")
|
|
|
|
db = ctx.lifespan_context["db"]
|
|
results = await db.query((params.arguments or {})["query"])
|
|
|
|
return types.CallToolResult(content=[types.TextContent(type="text", text=f"Query results: {results}")])
|
|
|
|
|
|
server = Server(
|
|
"example-server",
|
|
lifespan=server_lifespan,
|
|
on_list_tools=handle_list_tools,
|
|
on_call_tool=handle_call_tool,
|
|
)
|
|
|
|
|
|
async def run():
|
|
"""Run the server with lifespan management."""
|
|
async with mcp.server.stdio.stdio_server() as (read_stream, write_stream):
|
|
await server.run(
|
|
read_stream,
|
|
write_stream,
|
|
server.create_initialization_options(),
|
|
)
|
|
|
|
|
|
if __name__ == "__main__":
|
|
import asyncio
|
|
|
|
asyncio.run(run())
|