dify/api/core/mcp/server/streamable_http.py
NeatGuyCoding f929bfb94c
minor fix: remove duplicates, fix typo, and add restriction for get mcp server (#22170)
Signed-off-by: neatguycoding <15627489+NeatGuyCoding@users.noreply.github.com>
2025-07-11 09:40:17 +08:00

229 lines
8.9 KiB
Python

import json
import logging
from collections.abc import Mapping
from typing import Any, cast
from configs import dify_config
from controllers.web.passport import generate_session_id
from core.app.app_config.entities import VariableEntity, VariableEntityType
from core.app.entities.app_invoke_entities import InvokeFrom
from core.app.features.rate_limiting.rate_limit import RateLimitGenerator
from core.mcp import types
from core.mcp.types import INTERNAL_ERROR, INVALID_PARAMS, METHOD_NOT_FOUND
from core.mcp.utils import create_mcp_error_response
from core.model_runtime.utils.encoders import jsonable_encoder
from extensions.ext_database import db
from models.model import App, AppMCPServer, AppMode, EndUser
from services.app_generate_service import AppGenerateService
"""
Apply to MCP HTTP streamable server with stateless http
"""
logger = logging.getLogger(__name__)
class MCPServerStreamableHTTPRequestHandler:
def __init__(
self, app: App, request: types.ClientRequest | types.ClientNotification, user_input_form: list[VariableEntity]
):
self.app = app
self.request = request
mcp_server = db.session.query(AppMCPServer).filter(AppMCPServer.app_id == self.app.id).first()
if not mcp_server:
raise ValueError("MCP server not found")
self.mcp_server: AppMCPServer = mcp_server
self.end_user = self.retrieve_end_user()
self.user_input_form = user_input_form
@property
def request_type(self):
return type(self.request.root)
@property
def parameter_schema(self):
parameters, required = self._convert_input_form_to_parameters(self.user_input_form)
if self.app.mode in {AppMode.COMPLETION.value, AppMode.WORKFLOW.value}:
return {
"type": "object",
"properties": parameters,
"required": required,
}
return {
"type": "object",
"properties": {
"query": {"type": "string", "description": "User Input/Question content"},
**parameters,
},
"required": ["query", *required],
}
@property
def capabilities(self):
return types.ServerCapabilities(
tools=types.ToolsCapability(listChanged=False),
)
def response(self, response: types.Result | str):
if isinstance(response, str):
sse_content = f"event: ping\ndata: {response}\n\n".encode()
yield sse_content
return
json_response = types.JSONRPCResponse(
jsonrpc="2.0",
id=(self.request.root.model_extra or {}).get("id", 1),
result=response.model_dump(by_alias=True, mode="json", exclude_none=True),
)
json_data = json.dumps(jsonable_encoder(json_response))
sse_content = f"event: message\ndata: {json_data}\n\n".encode()
yield sse_content
def error_response(self, code: int, message: str, data=None):
request_id = (self.request.root.model_extra or {}).get("id", 1) or 1
return create_mcp_error_response(request_id, code, message, data)
def handle(self):
handle_map = {
types.InitializeRequest: self.initialize,
types.ListToolsRequest: self.list_tools,
types.CallToolRequest: self.invoke_tool,
types.InitializedNotification: self.handle_notification,
types.PingRequest: self.handle_ping,
}
try:
if self.request_type in handle_map:
return self.response(handle_map[self.request_type]())
else:
return self.error_response(METHOD_NOT_FOUND, f"Method not found: {self.request_type}")
except ValueError as e:
logger.exception("Invalid params")
return self.error_response(INVALID_PARAMS, str(e))
except Exception as e:
logger.exception("Internal server error")
return self.error_response(INTERNAL_ERROR, f"Internal server error: {str(e)}")
def handle_notification(self):
return "ping"
def handle_ping(self):
return types.EmptyResult()
def initialize(self):
request = cast(types.InitializeRequest, self.request.root)
client_info = request.params.clientInfo
client_name = f"{client_info.name}@{client_info.version}"
if not self.end_user:
end_user = EndUser(
tenant_id=self.app.tenant_id,
app_id=self.app.id,
type="mcp",
name=client_name,
session_id=generate_session_id(),
external_user_id=self.mcp_server.id,
)
db.session.add(end_user)
db.session.commit()
return types.InitializeResult(
protocolVersion=types.SERVER_LATEST_PROTOCOL_VERSION,
capabilities=self.capabilities,
serverInfo=types.Implementation(name="Dify", version=dify_config.project.version),
instructions=self.mcp_server.description,
)
def list_tools(self):
if not self.end_user:
raise ValueError("User not found")
return types.ListToolsResult(
tools=[
types.Tool(
name=self.app.name,
description=self.mcp_server.description,
inputSchema=self.parameter_schema,
)
],
)
def invoke_tool(self):
if not self.end_user:
raise ValueError("User not found")
request = cast(types.CallToolRequest, self.request.root)
args = request.params.arguments
if not args:
raise ValueError("No arguments provided")
if self.app.mode in {AppMode.WORKFLOW.value}:
args = {"inputs": args}
elif self.app.mode in {AppMode.COMPLETION.value}:
args = {"query": "", "inputs": args}
else:
args = {"query": args["query"], "inputs": {k: v for k, v in args.items() if k != "query"}}
response = AppGenerateService.generate(
self.app,
self.end_user,
args,
InvokeFrom.SERVICE_API,
streaming=self.app.mode == AppMode.AGENT_CHAT.value,
)
answer = ""
if isinstance(response, RateLimitGenerator):
for item in response.generator:
data = item
if isinstance(data, str) and data.startswith("data: "):
try:
json_str = data[6:].strip()
parsed_data = json.loads(json_str)
if parsed_data.get("event") == "agent_thought":
answer += parsed_data.get("thought", "")
except json.JSONDecodeError:
continue
if isinstance(response, Mapping):
if self.app.mode in {
AppMode.ADVANCED_CHAT.value,
AppMode.COMPLETION.value,
AppMode.CHAT.value,
AppMode.AGENT_CHAT.value,
}:
answer = response["answer"]
elif self.app.mode in {AppMode.WORKFLOW.value}:
answer = json.dumps(response["data"]["outputs"], ensure_ascii=False)
else:
raise ValueError("Invalid app mode")
# Not support image yet
return types.CallToolResult(content=[types.TextContent(text=answer, type="text")])
def retrieve_end_user(self):
return (
db.session.query(EndUser)
.filter(EndUser.external_user_id == self.mcp_server.id, EndUser.type == "mcp")
.first()
)
def _convert_input_form_to_parameters(self, user_input_form: list[VariableEntity]):
parameters: dict[str, dict[str, Any]] = {}
required = []
for item in user_input_form:
parameters[item.variable] = {}
if item.type in (
VariableEntityType.FILE,
VariableEntityType.FILE_LIST,
VariableEntityType.EXTERNAL_DATA_TOOL,
):
continue
if item.required:
required.append(item.variable)
# if the workflow republished, the parameters not changed
# we should not raise error here
try:
description = self.mcp_server.parameters_dict[item.variable]
except KeyError:
description = ""
parameters[item.variable]["description"] = description
if item.type in (VariableEntityType.TEXT_INPUT, VariableEntityType.PARAGRAPH):
parameters[item.variable]["type"] = "string"
elif item.type == VariableEntityType.SELECT:
parameters[item.variable]["type"] = "string"
parameters[item.variable]["enum"] = item.options
elif item.type == VariableEntityType.NUMBER:
parameters[item.variable]["type"] = "float"
return parameters, required