Dify Workflow MCP Tool Server

import { Server } from "@modelcontextprotocol/sdk/server/index.js"; import { ListToolsRequestSchema, CallToolRequestSchema, } from "@modelcontextprotocol/sdk/types.js"; import { appConfig } from "./config.js"; import { getWorkflowManager } from "./dify/api.js"; import { WorkflowManager } from "./dify/workflow.js"; /** * Server initialization error handler function */ export function handleInitializationError(error: unknown, exitProcess = true): never | void { console.error("Failed to retrieve or convert Dify Workflow information:"); if (error instanceof Error) { console.error(`Error message: ${error.message}`); console.error(`Error stack: ${error.stack}`); } else { console.error(`Unknown error type: ${error}`); } if (exitProcess) { process.exit(1); } throw error; } /** * Initialize workflow manager */ export async function initializeWorkflowManager( workflowManager = getWorkflowManager() ): Promise<WorkflowManager | undefined> { try { await workflowManager.initialize(); return workflowManager; } catch (error) { handleInitializationError(error); return undefined; // This line will never be executed but is necessary for type checking } } /** * Set up request handlers */ export function setupRequestHandlers(server: Server, workflowManager: WorkflowManager): void { // Tools list request handler server.setRequestHandler(ListToolsRequestSchema, async () => { const tools = workflowManager.getTools(); return { tools }; }); // Tool execution request handler server.setRequestHandler(CallToolRequestSchema, async (request) => { return handleCallToolRequest(workflowManager, request); }); } /** * Handle tool execution request */ export async function handleCallToolRequest(workflowManager: WorkflowManager, request: any) { const toolName = request.params.name; const workflowParams = request.params.arguments as Record<string, any> | undefined; // Error if parameters are undefined if (workflowParams === undefined) { const error = new Error(`Workflow parameters are undefined for tool '${toolName}'. Request: ${JSON.stringify(request)}`); console.error(error.message); throw error; } try { // Execute workflow const outputContent = await workflowManager.executeWorkflow(toolName, workflowParams); return { content: [ { type: "text", text: typeof outputContent === 'object' ? JSON.stringify(outputContent) : outputContent } ] }; } catch (error) { console.error(`Error executing tool '${toolName}':`, error); if (error instanceof Error) { console.error(`Parameters: ${JSON.stringify(workflowParams)}`); throw error; } else { const genericError = new Error(`Unknown error occurred while executing tool '${toolName}': ${error}`); console.error(`Parameters: ${JSON.stringify(workflowParams)}`); throw genericError; } } } /** * Create server instance */ export function createServer(serverConfig = appConfig.getServerConfig()): Server { return new Server(serverConfig, { capabilities: { tools: { enabled: true } } }); } /** * Set up and initialize MCP Server */ export async function setupServer( config = appConfig, workflowManagerFactory = getWorkflowManager ): Promise<Server> { // Validate configuration config.validateStrict(); // Get and initialize workflow manager const workflowManager = workflowManagerFactory(); await initializeWorkflowManager(workflowManager); // Create server const server = createServer(config.getServerConfig()); // Set up request handlers setupRequestHandlers(server, workflowManager); return server; }