feat: add MCP support (#20716)

Co-authored-by: QuantumGhost <obelisk.reg+git@gmail.com>

api/controllers/mcp/mcp.py

@@ -0,0 +1,104 @@
+from flask_restful import Resource, reqparse
+from pydantic import ValidationError
+
+from controllers.console.app.mcp_server import AppMCPServerStatus
+from controllers.mcp import api
+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
+
+
+class MCPAppApi(Resource):
+    def post(self, server_code):
+        def int_or_str(value):
+            if isinstance(value, (int, str)):
+                return value
+            else:
+                return None
+
+        parser = reqparse.RequestParser()
+        parser.add_argument("jsonrpc", type=str, required=True, location="json")
+        parser.add_argument("method", type=str, required=True, location="json")
+        parser.add_argument("params", type=dict, required=False, location="json")
+        parser.add_argument("id", type=int_or_str, required=False, location="json")
+        args = parser.parse_args()
+
+        request_id = args.get("id")
+
+        server = db.session.query(AppMCPServer).filter(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).filter(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)
+
+
+api.add_resource(MCPAppApi, "/server/<string:server_code>/mcp")