Files
dify/api/controllers/mcp/mcp.py
2025-08-25 09:27:01 +08:00

140 lines
5.8 KiB
Python

from typing import Optional, Union
from flask_restx import Resource, reqparse
from pydantic import ValidationError
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
from core.mcp.server.streamable_http import MCPServerStreamableHTTPRequestHandler
from core.mcp.types import ClientNotification, ClientRequest
from core.mcp.utils import create_mcp_error_response
from extensions.ext_database import db
from libs import helper
from models.model import App, AppMCPServer, AppMode
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
"""
# Parse and validate all arguments
args = mcp_request_parser.parse_args()
request_id: Optional[Union[int, str]] = args.get("id")
server = db.session.query(AppMCPServer).where(AppMCPServer.server_code == server_code).first()
if not server:
return helper.compact_generate_response(
create_mcp_error_response(request_id, types.INVALID_REQUEST, "Server Not Found")
)
if server.status != AppMCPServerStatus.ACTIVE:
return helper.compact_generate_response(
create_mcp_error_response(request_id, types.INVALID_REQUEST, "Server is not active")
)
app = db.session.query(App).where(App.id == server.app_id).first()
if not app:
return helper.compact_generate_response(
create_mcp_error_response(request_id, types.INVALID_REQUEST, "App Not Found")
)
if app.mode in {AppMode.ADVANCED_CHAT.value, AppMode.WORKFLOW.value}:
workflow = app.workflow
if workflow is None:
return helper.compact_generate_response(
create_mcp_error_response(request_id, types.INVALID_REQUEST, "App is unavailable")
)
user_input_form = workflow.user_input_form(to_old_structure=True)
else:
app_model_config = app.app_model_config
if app_model_config is None:
return helper.compact_generate_response(
create_mcp_error_response(request_id, types.INVALID_REQUEST, "App is unavailable")
)
features_dict = app_model_config.to_dict()
user_input_form = features_dict.get("user_input_form", [])
converted_user_input_form: list[VariableEntity] = []
try:
for item in user_input_form:
variable_type = item.get("type", "") or list(item.keys())[0]
variable = item[variable_type]
converted_user_input_form.append(
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 [],
)
)
except ValidationError as e:
return helper.compact_generate_response(
create_mcp_error_response(request_id, types.INVALID_PARAMS, f"Invalid user_input_form: {str(e)}")
)
try:
request: ClientRequest | ClientNotification = ClientRequest.model_validate(args)
except ValidationError as e:
try:
notification = ClientNotification.model_validate(args)
request = notification
except ValidationError as e:
return helper.compact_generate_response(
create_mcp_error_response(request_id, 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)