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mcp-nextcloud/nextcloud_mcp_server/stdio.py
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Chris CoutinhoandClaude Opus 4.6 f340380898 fix: address third round of review feedback
Add BasicAuthLifespanContext Protocol to make the contract between
StdioContext and get_client() explicit and type-safe. Document why
mcp.get_context() is required for non-template resources. Add News
and Collectives to README Supported Apps table, fix transport default.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-07 23:59:39 +02:00

109 lines
3.6 KiB
Python

"""Lightweight stdio transport for the Nextcloud MCP server.
Provides a minimal FastMCP instance suitable for ``mcp.run(transport="stdio")``.
Only single-user BasicAuth mode is supported. Background sync, semantic search,
OAuth, and observability infrastructure are deliberately excluded.
"""
from __future__ import annotations
import logging
from collections.abc import AsyncIterator
from contextlib import asynccontextmanager
from dataclasses import dataclass
from mcp.server.fastmcp import Context, FastMCP
from nextcloud_mcp_server.client import NextcloudClient
from nextcloud_mcp_server.config import get_settings
from nextcloud_mcp_server.config_validators import AuthMode, validate_configuration
from nextcloud_mcp_server.context import BasicAuthLifespanContext
from nextcloud_mcp_server.context import get_client as get_nextcloud_client
from nextcloud_mcp_server.server import AVAILABLE_APPS
logger = logging.getLogger(__name__)
@dataclass
class StdioContext(BasicAuthLifespanContext):
"""Minimal lifespan context for stdio transport.
Implements :class:`~nextcloud_mcp_server.context.BasicAuthLifespanContext`
so that :func:`~nextcloud_mcp_server.context.get_client` recognises it
as a single-user BasicAuth context.
"""
client: NextcloudClient
@asynccontextmanager
async def stdio_lifespan(server: FastMCP) -> AsyncIterator[StdioContext]:
"""Create and tear down a single :class:`NextcloudClient`."""
logger.info("Starting MCP server in stdio mode (single-user BasicAuth)")
client = NextcloudClient.from_env()
try:
yield StdioContext(client=client)
finally:
await client.close()
logger.info("stdio session shut down")
def get_stdio_mcp(enabled_apps: list[str] | None = None) -> FastMCP:
"""Return a :class:`FastMCP` instance configured for stdio transport.
Parameters
----------
enabled_apps:
Whitelist of Nextcloud app names to register. ``None`` means all.
Raises
------
ValueError
If the current configuration is not single-user BasicAuth.
"""
settings = get_settings()
mode, config_errors = validate_configuration(settings)
if config_errors:
raise ValueError(
f"Configuration validation failed for {mode.value} mode:\n"
+ "\n".join(f" - {err}" for err in config_errors)
)
if mode != AuthMode.SINGLE_USER_BASIC:
raise ValueError(
f"stdio transport only supports single-user BasicAuth mode, "
f"but detected {mode.value}. Set NEXTCLOUD_HOST, NEXTCLOUD_USERNAME, "
f"and NEXTCLOUD_PASSWORD."
)
mcp = FastMCP("Nextcloud MCP", lifespan=stdio_lifespan)
# --- capabilities resource (mirrors app.py) ---
# NOTE: mcp.get_context() is required here because FastMCP's
# FunctionResource (non-template resources) does not support
# context parameter injection — only template resources do.
@mcp.resource("nc://capabilities")
async def nc_get_capabilities():
"""Get the Nextcloud Host capabilities"""
ctx: Context = mcp.get_context()
client = await get_nextcloud_client(ctx)
return await client.capabilities()
# --- tool registration ---
if enabled_apps is None:
enabled_apps = list(AVAILABLE_APPS.keys())
for app_name in enabled_apps:
if app_name in AVAILABLE_APPS:
logger.info("Configuring %s tools", app_name)
AVAILABLE_APPS[app_name](mcp)
else:
logger.warning(
"Unknown app: %s. Available apps: %s",
app_name,
list(AVAILABLE_APPS.keys()),
)
return mcp