Implement add-subtask MCP command for adding subtasks to existing tasks

mcp-server/src/tools/add-subtask.js

@@ -0,0 +1,55 @@
+/**
+ * tools/add-subtask.js
+ * Tool for adding subtasks to existing tasks
+ */
+
+import { z } from "zod";
+import {
+  handleApiResult,
+  createErrorResponse
+} from "./utils.js";
+import { addSubtaskDirect } from "../core/task-master-core.js";
+
+/**
+ * Register the addSubtask tool with the MCP server
+ * @param {Object} server - FastMCP server instance
+ */
+export function registerAddSubtaskTool(server) {
+  server.addTool({
+    name: "add_subtask",
+    description: "Add a subtask to an existing task",
+    parameters: z.object({
+      id: z.string().describe("Parent task ID (required)"),
+      taskId: z.string().optional().describe("Existing task ID to convert to subtask"),
+      title: z.string().optional().describe("Title for the new subtask (when creating a new subtask)"),
+      description: z.string().optional().describe("Description for the new subtask"),
+      details: z.string().optional().describe("Implementation details for the new subtask"),
+      status: z.string().optional().describe("Status for the new subtask (default: 'pending')"),
+      dependencies: z.string().optional().describe("Comma-separated list of dependency IDs for the new subtask"),
+      file: z.string().optional().describe("Path to the tasks file (default: tasks/tasks.json)"),
+      skipGenerate: z.boolean().optional().describe("Skip regenerating task files"),
+      projectRoot: z.string().optional().describe("Root directory of the project (default: current working directory)")
+    }),
+    execute: async (args, { log }) => {
+      try {
+        log.info(`Adding subtask with args: ${JSON.stringify(args)}`);
+        
+        // Call the direct function wrapper
+        const result = await addSubtaskDirect(args, log);
+        
+        // Log result
+        if (result.success) {
+          log.info(`Subtask added successfully: ${result.data.message}`);
+        } else {
+          log.error(`Failed to add subtask: ${result.error.message}`);
+        }
+        
+        // Use handleApiResult to format the response
+        return handleApiResult(result, log, 'Error adding subtask');
+      } catch (error) {
+        log.error(`Error in addSubtask tool: ${error.message}`);
+        return createErrorResponse(error.message);
+      }
+    },
+  });
+}