translation/translated/documents/course/04-workflows/09-adding-a-third-step.md

# 添加第三个步骤

让我们通过添加第三个步骤来扩展您的工作流，该步骤生成内容摘要。

## 创建摘要步骤

将此新步骤添加到您的工作流文件中：

```typescript
const generateSummaryStep = createStep({
  id: "generate-summary",
  description: "Creates a summary of the content",
  inputSchema: z.object({
    content: z.string(),
    type: z.string(),
    wordCount: z.number(),
    metadata: z.object({
      readingTime: z.number(),
      difficulty: z.enum(["easy", "medium", "hard"]),
      processedAt: z.string(),
    }),
  }),
  outputSchema: z.object({
    content: z.string(),
    type: z.string(),
    wordCount: z.number(),
    metadata: z.object({
      readingTime: z.number(),
      difficulty: z.enum(["easy", "medium", "hard"]),
      processedAt: z.string(),
    }),
    summary: z.string(),
  }),
  execute: async ({ inputData }) => {
    const { content, type, wordCount, metadata } = inputData;

    // Create a simple summary from first sentence
    const sentences = content
      .split(/[.!?]+/)
      .filter((s) => s.trim().length > 0);
    const firstSentence = sentences[0]?.trim() + ".";

    // Generate summary based on content length
    let summary = firstSentence;
    if (wordCount > 50) {
      summary += ` This ${type} contains ${wordCount} words and takes approximately ${metadata.readingTime} minute(s) to read.`;
    }

    console.log(`📝 Generated summary: ${summary.length} characters`);

    return {
      content,
      type,
      wordCount,
      metadata,
      summary,
    };
  },
});
```

## 理解模式

注意此步骤如何：

- 将前一个步骤的输出作为输入
- 添加新数据（`summary`）同时保留现有数据
- 遵循与其他步骤相同的结构

您的第三个步骤已准备就绪！接下来，您将更新工作流以包含所有三个步骤。