eyaltoledano/claude-task-master · error

Invalid template structure: missing required fields (id, pro

Error message

Invalid template structure: missing required fields (id, prompts.default)

What it means

Fallback structural check in PromptManager.loadTemplate, used only when no schema validator is available (validatePrompt is true/absent). It rejects templates missing any of the minimum required fields: id, prompts, or prompts.default, ensuring the manager can always resolve a default prompt.

Source

Thrown at scripts/modules/prompt-manager.js:149

		const template = this.prompts.get(promptId);

		if (!template) {
			throw new Error(`Prompt template '${promptId}' not found`);
		}

		// Schema validation if available (do this first for detailed errors)
		if (this.validatePrompt && this.validatePrompt !== true) {
			const valid = this.validatePrompt(template);
			if (!valid) {
				const errors = this.validatePrompt.errors
					.map((err) => `${err.instancePath || 'root'}: ${err.message}`)
					.join(', ');
				throw new Error(`Schema validation failed: ${errors}`);
			}
		} else {
			// Fallback basic validation if no schema validation available
			if (!template.id || !template.prompts || !template.prompts.default) {
				throw new Error(
					'Invalid template structure: missing required fields (id, prompts.default)'
				);
			}
		}

		return template;
	}

	/**
	 * Validate parameters against template schema
	 * @private
	 */
	validateParameters(template, variables) {
		if (!template.parameters) return;

		const errors = [];

		for (const [paramName, paramConfig] of Object.entries(

View on GitHub (pinned to c0c98d367c)

Solutions

1. Add a `prompts.default` entry to the template (plus its `id`).
2. Ensure the template object has all three: id, prompts, prompts.default.
3. Fix the source JSON/file if the template was truncated on load.
4. Optionally enable schema validation so future errors point at exact fields.

Example fix

// before
{ "id": "research-gen", "prompts": { "research": { "user": "..." } } }
// after
{ "id": "research-gen", "prompts": { "default": { "system": "...", "user": "..." }, "research": { "user": "..." } } }

function assertTemplateStructure(tpl) {
  if (!tpl || !tpl.id || !tpl.prompts || !tpl.prompts.default) {
    throw new Error(`Template ${tpl?.id ?? '(unknown)'} missing required fields: id, prompts.default`);
  }
}
// run before registering the template

const hasRequiredTemplateFields = (t) =>
  Boolean(t && typeof t === 'object' && t.id && t.prompts && t.prompts.default);

if (!hasRequiredTemplateFields(rawTemplate)) {
  throw new Error('Custom template must define id and prompts.default before registration');
}

When it happens

Trigger: Calling template(promptId) on a template that lacks `id`, lacks `prompts`, or lacks `prompts.default`, while the manager runs without a JSON-Schema validator — i.e. structurally broken/incomplete template objects.

Common situations: Minimal custom template stubs that only define variants (e.g. prompts.research) without a `default`, truncated/failed JSON loads, or templates copied from examples that assumed schema validation was active.

Understand the failure class

Background: "Missing required field" and "field is required" errors: why libraries reject payloads that omit mandatory fields — this error's family across 20 libraries.

Related errors

• Schema validation failed: ${errors}
• Dynamic slash command "${name}" must contain $ARGUMENTS plac
• Prompt template '${promptId}' not found
• Parameter validation failed: ${errors.join('; ')}
• Failed to load prompt template: ${error.message}

AI-assisted analysis of eyaltoledano/claude-task-master@c0c98d367c (2026-08-29). Data as JSON: /api/errors/c286961a2950dcfd. Report an issue: GitHub.