AI翻訳自動化 — ブログを11言語で公開するスマートパイプライン

[D1: posts table]
       ↓
[/api/cron/translate] — runs daily, max 5 translations per day
       ↓
[Select post with no translation for target language]
       ↓
[Claude API — translate title, description, content_md]
       ↓
[D1: i18n_posts table — INSERT translated content]
       ↓
[SEO ping — IndexNow for translated URL]
       ↓
[Telegram report — translation completed]

// lib/translate.ts
import Anthropic from '@anthropic-ai/sdk'

const client = new Anthropic({ apiKey: process.env.ANTHROPIC_API_KEY ?? '' })

export async function translatePost(
  post: { title: string; description: string; content_md: string },
  targetLang: string,
  langName: string
): Promise<{ title: string; description: string; content_md: string }> {

  // Dev guard — never call API locally
  if (process.env.NODE_ENV === 'development') {
    return {
      title: `[${targetLang.toUpperCase()}] ${post.title}`,
      description: `[${targetLang.toUpperCase()}] ${post.description}`,
      content_md: `[${targetLang.toUpperCase()}] ${post.content_md.substring(0, 100)}...`
    }

  const message = await client.messages.create({
    model: 'claude-3-5-haiku-20241022', // Cost-optimized model
    max_tokens: 4096,
    messages: [{
      role: 'user',
      content: `Translate the following Korean blog content to ${langName} (${targetLang}).

Requirements:
- Preserve all Markdown formatting (headers, tables, code blocks, bold/italic)
- Keep technical terms, brand names, and tool names in their original form
- Adapt cultural references for the target audience where appropriate
- Maintain SEO keyword intent — translate naturally, not literally
- For RTL languages (Arabic), ensure text flows right-to-left

Title: ${post.title}
---
Description: ${post.description}
---
Content:
${post.content_md}

Return JSON: { "title": "...", "description": "...", "content_md": "..." }`
    }]
  })

  const text = message.content[0].type === 'text' ? message.content[0].text : '{}'

  try {
    return JSON.parse(text)
  } catch {
    throw new Error(`Translation parsing failed for ${targetLang}`)
  }

/blog/[slug]           ← Korean (default)
/en/blog/[slug]-en     ← English
/ja/blog/[slug]-ja     ← Japanese
/zh/blog/[slug]-zh     ← Chinese

<link rel="alternate" hreflang="ko" href="https://millionscode.com/blog/slug" />
<link rel="alternate" hreflang="en" href="https://millionscode.com/en/blog/slug-en" />
<link rel="alternate" hreflang="ja" href="https://millionscode.com/ja/blog/slug-ja" />
<link rel="alternate" hreflang="x-default" href="https://millionscode.com/blog/slug" />