eyaltoledano/claude-task-master · error

Parent task with ID ${parentIdNum} not found

Error message

Parent task with ID ${parentIdNum} not found

What it means

addSubtask converts the parentId to a number and searches the tasks array for a matching task; this error is thrown when no top-level task has that ID. The parent must exist before a subtask can be attached to it.

Source

Thrown at scripts/modules/task-manager/add-subtask.js:40

	context = {}
) {
	const { projectRoot, tag } = context;
	try {
		log('info', `Adding subtask to parent task ${parentId}...`);

		// Read the existing tasks with proper context
		const data = readJSON(tasksPath, projectRoot, tag);
		if (!data || !data.tasks) {
			throw new Error(`Invalid or missing tasks file at ${tasksPath}`);
		}

		// Convert parent ID to number
		const parentIdNum = parseInt(parentId, 10);

		// Find the parent task
		const parentTask = data.tasks.find((t) => t.id === parentIdNum);
		if (!parentTask) {
			throw new Error(`Parent task with ID ${parentIdNum} not found`);
		}

		// Initialize subtasks array if it doesn't exist
		if (!parentTask.subtasks) {
			parentTask.subtasks = [];
		}

		let newSubtask;

		// Case 1: Convert an existing task to a subtask
		if (existingTaskId !== null) {
			const existingTaskIdNum = parseInt(existingTaskId, 10);

			// Find the existing task
			const existingTaskIndex = data.tasks.findIndex(
				(t) => t.id === existingTaskIdNum
			);
			if (existingTaskIndex === -1) {

View on GitHub (pinned to c0c98d367c)

Solutions

1. Run task-master list (or read the tasks file) to confirm the parent task ID exists.
2. Use the ID of an existing top-level task as parentId.
3. If the task was deleted, recreate it or pick another parent.
4. Check you are operating in the correct tag/context whose task list contains the parent.

Example fix

// before
await addSubtask(tasksPath, '99', '5'); // no task 99
// after
await addSubtask(tasksPath, '1', '5'); // task 1 exists

const data = readJSON(tasksPath, projectRoot, tag);
const parentIdNum = parseInt(parentId, 10);
if (!data.tasks.some(t => t.id === parentIdNum)) {
  throw new Error(`Parent task ${parentIdNum} not found in ${tasksPath}`);
}

function parentExists(data, id) {
  const n = Number(id);
  return Array.isArray(data?.tasks) && data.tasks.some(t => t.id === n);
}

try {
  await addSubtask(tasksPath, parentId, opts);
} catch (err) {
  if (err.message.includes('not found')) {
    const missing = err.message.match(/ID (\d+)/)?.[1];
    console.error(`Create or locate task ${missing} first`);
  } else throw err;
}

When it happens

Trigger: Calling addSubtask with a parentId that is not any existing task's id, e.g. beyond the highest task ID or a deleted task.

Common situations: Typos in the parent ID, referencing a task from a different tag's task list, or using a subtask composite ID ('1.2') where only a top-level task ID is valid.

Related errors

• Task with ID ${existingTaskIdNum} not found
• Tag "${targetTag}" not found.
• Invalid iterations: ${iterations}. Must be a positive intege
• Invalid format: ${options.format}. Valid formats are: text,
• NOT_FOUND

AI-assisted analysis of eyaltoledano/claude-task-master@c0c98d367c (2026-08-29). Data as JSON: /api/errors/09061cbcfc578d3b. Report an issue: GitHub.