feat: update teaser generation to use Opus 4.6 with adaptive thinking

Upgrade the Claude API call to use claude-opus-4-6 with adaptive
thinking, a dedicated system prompt, and proper handling of thinking
blocks in the response. Add evaluation script for manually reviewing
generated teasers against recent articles.

Author: limulus

11ty/generate-teasers.ts

@@ -119,28 +119,26 @@ export function insertTeaserIntoFrontmatter(fileContent: string, teaser: string)
   return `${beforeClose}${formatTeaserYaml(teaser)}\n${afterClose}`
 }
 
-async function generateTeaser(
+export async function generateTeaser(
   anthropic: Anthropic,
   title: string,
   content: string
 ): Promise<string> {
   const message = await anthropic.messages.create({
-    // Using claude-opus-4-5 alias to auto-update within Opus 4.5.x releases.
-    // Anthropic provides 60 days notice before deprecation.
-    // Check quarterly for new major versions: https://platform.claude.com/docs/en/about-claude/models/overview
-    // Last checked: February 2026
-    model: 'claude-opus-4-5',
-    max_tokens: 300,
+    model: 'claude-opus-4-6',
+    max_tokens: 2048,
+    thinking: { type: 'adaptive' },
+    system: TEASER_PROMPT,
     messages: [
       {
         role: 'user',
-        content: `${TEASER_PROMPT}\n\n---\n\nTitle: ${title}\n\n${content}`,
+        content: `Title: ${title}\n\n${content}`,
       },
     ],
   })
 
-  const block = message.content[0]
-  if (block.type !== 'text') {
+  const block = message.content.findLast((b) => b.type === 'text')
+  if (!block || block.type !== 'text') {
     throw new Error('Unexpected response type from Anthropic API')
   }
 

bin/evaluate-teasers.ts

@@ -0,0 +1,63 @@
+import Anthropic from '@anthropic-ai/sdk'
+import { globby } from 'globby'
+import matter from 'gray-matter'
+import { readFile } from 'node:fs/promises'
+
+import { generateTeaser } from '../11ty/generate-teasers.ts'
+
+interface Article {
+  title: string
+  date: Date
+  content: string
+}
+
+async function main() {
+  const count = parseInt(process.argv[2] ?? '5', 10)
+  const anthropic = new Anthropic()
+  const files = await globby('www/**/*.md')
+  const articles: Article[] = []
+
+  for (const filePath of files) {
+    const fileContent = await readFile(filePath, 'utf-8')
+    const parsed = matter(fileContent)
+
+    const tags: string[] = parsed.data.tags ?? []
+    if (!tags.includes('article')) continue
+
+    articles.push({
+      title: parsed.data.title as string,
+      date: new Date(parsed.data.date as string),
+      content: parsed.content,
+    })
+  }
+
+  articles.sort((a, b) => b.date.getTime() - a.date.getTime())
+  const latest = articles.slice(0, count)
+
+  console.log(`Evaluating teasers for ${latest.length} articles\n`)
+
+  for (const article of latest) {
+    const preview = article.content.trim().slice(0, 500)
+
+    console.log('='.repeat(72))
+    console.log(`Title: ${article.title}`)
+    console.log(`Date:  ${article.date.toISOString().slice(0, 10)}`)
+    console.log('-'.repeat(72))
+    console.log(preview)
+    if (article.content.trim().length > 500) console.log('[...]')
+    console.log('-'.repeat(72))
+
+    const teaser = await generateTeaser(anthropic, article.title, article.content)
+
+    console.log(`Teaser (${teaser.length} chars):`)
+    console.log(teaser)
+    console.log()
+  }
+
+  console.log('Done.')
+}
+
+main().catch((error: unknown) => {
+  console.error(error)
+  process.exit(1)
+})

package-lock.json

@@ -84,7 +84,7 @@
     "typescript": "^5.9.3"
   },
   "devDependencies": {
-    "@anthropic-ai/sdk": "^0.72.1",
+    "@anthropic-ai/sdk": "^0.73.0",
     "@aws-sdk/client-cloudfront": "^3.859.0",
     "@dprint/formatter": "^0.4.1",
     "@types/aws-cloudfront-function": "^1.0.5",