linshenkx/prompt-optimizer · error · OptimizationError

Target prompt is required

Error message

Target prompt is required

What it means

Optimization requests must include a non-empty targetPrompt; validateOptimizationRequest throws OptimizationError when targetPrompt is missing, empty, or only whitespace. This guard runs before any model or template work in both optimizePrompt and optimizePromptStream.

Source

Thrown at packages/core/src/services/prompt/service.ts:849

    } catch (error) {
      const errorMessage =
        error instanceof Error ? error.message : String(error);
      throw new IterationError(
        originalPrompt,
        iterateInput,
        `Iteration failed: ${errorMessage}`,
      );
    }
  }

  // === 新增：支持提示词类型的增强方法 ===

  /**
   * 验证优化请求参数
   */
  private validateOptimizationRequest(request: OptimizationRequest) {
    if (!request.targetPrompt?.trim()) {
      throw new OptimizationError("", "Target prompt is required");
    }
    if (!request.modelKey?.trim()) {
      throw new OptimizationError(request.targetPrompt, "Model key is required");
    }
  }

  private hasInputImages(request: OptimizationRequest): request is OptimizationRequest & { inputImages: NonNullable<OptimizationRequest["inputImages"]> } {
    return Array.isArray(request.inputImages) && request.inputImages.length > 0;
  }

  private hasTestInputImages(inputImages?: ImageInputRef[]): inputImages is ImageInputRef[] {
    return Array.isArray(inputImages) && inputImages.length > 0;
  }

  private getSafeTestErrorMessage(error: unknown, inputImages?: ImageInputRef[]): string {
    let message = error instanceof Error ? error.message : String(error);
    if (!this.hasTestInputImages(inputImages)) {
      return message;

View on GitHub (pinned to 3e677b1d9f)

Solutions

1. Validate and trim targetPrompt before calling the API
2. Disable the optimize action in the UI until a non-empty prompt is entered
3. Log the request payload shape in tests to catch missing fields early

Example fix

// before
await service.optimizePrompt({ targetPrompt: '   ', modelKey });

// after
const target = targetPrompt?.trim();
if (!target) throw new Error('Enter a prompt to optimize');
await service.optimizePrompt({ targetPrompt: target, modelKey });

const target = request.targetPrompt?.trim() ?? '';
if (!target) throw new Error('targetPrompt is required');

const hasTargetPrompt = (
  r: Partial<OptimizationRequest>
): r is OptimizationRequest =>
  typeof r.targetPrompt === 'string' && r.targetPrompt.trim().length > 0;

try {
  await svc.optimizePrompt(req);
} catch (e) {
  if (e instanceof OptimizationError && e.message === 'Target prompt is required') {
    // show empty-input validation message to user
  } else throw e;
}

When it happens

Trigger: Calling optimizePrompt/optimizePromptStream with targetPrompt undefined, '', or a string of spaces/newlines; e.g. submitting the optimize form before typing a prompt.

Common situations: UI form submitted before user input; programmatic callers passing an object built from empty state; trailing-whitespace-only strings from copy/paste.

Understand the failure class

Background: Missing required parameter errors: what 'X is required' and 'the required X param is missing' mean, and how to fix them — this error's family across 27 libraries.

Related errors

• ${label} testCaseId must not be empty.
• Function mode (functionMode) cannot be empty
• CONFIG_INVALID
• Model config cannot be empty
• User prompt is required

AI-assisted analysis of linshenkx/prompt-optimizer@3e677b1d9f (2026-08-27). Data as JSON: /api/errors/3d674acdef418244. Report an issue: GitHub.