mirror of https://github.com/langgenius/dify.git
200 lines
8.4 KiB
Python
200 lines
8.4 KiB
Python
from typing import Union
|
|
|
|
from flask import Response
|
|
from flask_restx import Resource, reqparse
|
|
from pydantic import ValidationError
|
|
from sqlalchemy.orm import Session
|
|
|
|
from controllers.console.app.mcp_server import AppMCPServerStatus
|
|
from controllers.mcp import mcp_ns
|
|
from core.app.app_config.entities import VariableEntity
|
|
from core.mcp import types as mcp_types
|
|
from extensions.ext_database import db
|
|
from libs import helper
|
|
from models.model import App, AppMCPServer, AppMode
|
|
|
|
|
|
class MCPRequestError(Exception):
|
|
"""Custom exception for MCP request processing errors"""
|
|
|
|
def __init__(self, error_code: int, message: str):
|
|
self.error_code = error_code
|
|
self.message = message
|
|
super().__init__(message)
|
|
|
|
|
|
def int_or_str(value):
|
|
"""Validate that a value is either an integer or string."""
|
|
if isinstance(value, (int, str)):
|
|
return value
|
|
else:
|
|
return None
|
|
|
|
|
|
# Define parser for both documentation and validation
|
|
mcp_request_parser = reqparse.RequestParser()
|
|
mcp_request_parser.add_argument(
|
|
"jsonrpc", type=str, required=True, location="json", help="JSON-RPC version (should be '2.0')"
|
|
)
|
|
mcp_request_parser.add_argument("method", type=str, required=True, location="json", help="The method to invoke")
|
|
mcp_request_parser.add_argument("params", type=dict, required=False, location="json", help="Parameters for the method")
|
|
mcp_request_parser.add_argument(
|
|
"id", type=int_or_str, required=False, location="json", help="Request ID for tracking responses"
|
|
)
|
|
|
|
|
|
@mcp_ns.route("/server/<string:server_code>/mcp")
|
|
class MCPAppApi(Resource):
|
|
@mcp_ns.expect(mcp_request_parser)
|
|
@mcp_ns.doc("handle_mcp_request")
|
|
@mcp_ns.doc(description="Handle Model Context Protocol (MCP) requests for a specific server")
|
|
@mcp_ns.doc(params={"server_code": "Unique identifier for the MCP server"})
|
|
@mcp_ns.doc(
|
|
responses={
|
|
200: "MCP response successfully processed",
|
|
400: "Invalid MCP request or parameters",
|
|
404: "Server or app not found",
|
|
}
|
|
)
|
|
def post(self, server_code: str):
|
|
"""Handle MCP requests for a specific server.
|
|
|
|
Processes JSON-RPC formatted requests according to the Model Context Protocol specification.
|
|
Validates the server status and associated app before processing the request.
|
|
|
|
Args:
|
|
server_code: Unique identifier for the MCP server
|
|
|
|
Returns:
|
|
dict: JSON-RPC response from the MCP handler
|
|
|
|
Raises:
|
|
ValidationError: Invalid request format or parameters
|
|
"""
|
|
args = mcp_request_parser.parse_args()
|
|
request_id: Union[int, str] | None = args.get("id")
|
|
mcp_request = self._parse_mcp_request(args)
|
|
|
|
with Session(db.engine, expire_on_commit=False) as session:
|
|
# Get MCP server and app
|
|
mcp_server, app = self._get_mcp_server_and_app(server_code, session)
|
|
self._validate_server_status(mcp_server)
|
|
|
|
# Get user input form
|
|
user_input_form = self._get_user_input_form(app)
|
|
|
|
# Handle notification vs request differently
|
|
return self._process_mcp_message(mcp_request, request_id, app, mcp_server, user_input_form, session)
|
|
|
|
def _get_mcp_server_and_app(self, server_code: str, session: Session) -> tuple[AppMCPServer, App]:
|
|
"""Get and validate MCP server and app in one query session"""
|
|
mcp_server = session.query(AppMCPServer).where(AppMCPServer.server_code == server_code).first()
|
|
if not mcp_server:
|
|
raise MCPRequestError(mcp_types.INVALID_REQUEST, "Server Not Found")
|
|
|
|
app = session.query(App).where(App.id == mcp_server.app_id).first()
|
|
if not app:
|
|
raise MCPRequestError(mcp_types.INVALID_REQUEST, "App Not Found")
|
|
|
|
return mcp_server, app
|
|
|
|
def _validate_server_status(self, mcp_server: AppMCPServer):
|
|
"""Validate MCP server status"""
|
|
if mcp_server.status != AppMCPServerStatus.ACTIVE:
|
|
raise MCPRequestError(mcp_types.INVALID_REQUEST, "Server is not active")
|
|
|
|
def _process_mcp_message(
|
|
self,
|
|
mcp_request: mcp_types.ClientRequest | mcp_types.ClientNotification,
|
|
request_id: Union[int, str] | None,
|
|
app: App,
|
|
mcp_server: AppMCPServer,
|
|
user_input_form: list[VariableEntity],
|
|
session: Session,
|
|
) -> Response:
|
|
"""Process MCP message (notification or request)"""
|
|
if isinstance(mcp_request, mcp_types.ClientNotification):
|
|
return self._handle_notification(mcp_request)
|
|
else:
|
|
return self._handle_request(mcp_request, request_id, app, mcp_server, user_input_form, session)
|
|
|
|
def _handle_notification(self, mcp_request: mcp_types.ClientNotification) -> Response:
|
|
"""Handle MCP notification"""
|
|
# For notifications, only support init notification
|
|
if mcp_request.root.method != "notifications/initialized":
|
|
raise MCPRequestError(mcp_types.INVALID_REQUEST, "Invalid notification method")
|
|
# Return HTTP 202 Accepted for notifications (no response body)
|
|
return Response("", status=202, content_type="application/json")
|
|
|
|
def _handle_request(
|
|
self,
|
|
mcp_request: mcp_types.ClientRequest,
|
|
request_id: Union[int, str] | None,
|
|
app: App,
|
|
mcp_server: AppMCPServer,
|
|
user_input_form: list[VariableEntity],
|
|
session: Session,
|
|
) -> Response:
|
|
"""Handle MCP request"""
|
|
if request_id is None:
|
|
raise MCPRequestError(mcp_types.INVALID_REQUEST, "Request ID is required")
|
|
|
|
result = self._handle_mcp_request(app, mcp_server, mcp_request, user_input_form, session, request_id)
|
|
if result is None:
|
|
# This shouldn't happen for requests, but handle gracefully
|
|
raise MCPRequestError(mcp_types.INTERNAL_ERROR, "No response generated for request")
|
|
|
|
return helper.compact_generate_response(result.model_dump(by_alias=True, mode="json", exclude_none=True))
|
|
|
|
def _get_user_input_form(self, app: App) -> list[VariableEntity]:
|
|
"""Get and convert user input form"""
|
|
# Get raw user input form based on app mode
|
|
if app.mode in {AppMode.ADVANCED_CHAT, AppMode.WORKFLOW}:
|
|
if not app.workflow:
|
|
raise MCPRequestError(mcp_types.INVALID_REQUEST, "App is unavailable")
|
|
raw_user_input_form = app.workflow.user_input_form(to_old_structure=True)
|
|
else:
|
|
if not app.app_model_config:
|
|
raise MCPRequestError(mcp_types.INVALID_REQUEST, "App is unavailable")
|
|
features_dict = app.app_model_config.to_dict()
|
|
raw_user_input_form = features_dict.get("user_input_form", [])
|
|
|
|
# Convert to VariableEntity objects
|
|
try:
|
|
return self._convert_user_input_form(raw_user_input_form)
|
|
except ValidationError as e:
|
|
raise MCPRequestError(mcp_types.INVALID_PARAMS, f"Invalid user_input_form: {str(e)}")
|
|
|
|
def _convert_user_input_form(self, raw_form: list[dict]) -> list[VariableEntity]:
|
|
"""Convert raw user input form to VariableEntity objects"""
|
|
return [self._create_variable_entity(item) for item in raw_form]
|
|
|
|
def _create_variable_entity(self, item: dict) -> VariableEntity:
|
|
"""Create a single VariableEntity from raw form item"""
|
|
variable_type = item.get("type", "") or list(item.keys())[0]
|
|
variable = item[variable_type]
|
|
|
|
return VariableEntity(
|
|
type=variable_type,
|
|
variable=variable.get("variable"),
|
|
description=variable.get("description") or "",
|
|
label=variable.get("label"),
|
|
required=variable.get("required", False),
|
|
max_length=variable.get("max_length"),
|
|
options=variable.get("options") or [],
|
|
)
|
|
|
|
def _parse_mcp_request(self, args: dict) -> mcp_types.ClientRequest | mcp_types.ClientNotification:
|
|
"""Parse and validate MCP request"""
|
|
try:
|
|
return mcp_types.ClientRequest.model_validate(args)
|
|
except ValidationError:
|
|
try:
|
|
return mcp_types.ClientNotification.model_validate(args)
|
|
except ValidationError as e:
|
|
raise MCPRequestError(mcp_types.INVALID_PARAMS, f"Invalid MCP request: {str(e)}")
|
|
|
|
mcp_server_handler = MCPServerStreamableHTTPRequestHandler(app, request, converted_user_input_form)
|
|
response = mcp_server_handler.handle()
|
|
return helper.compact_generate_response(response)
|