How to deal with archive pages of blog posts in Sanity

Yes, creating a singleton for the blog archive page is a great approach! Here's how you'd set this up:

The Singleton Approach

A singleton document is perfect for your blog archive page because it's a unique page that only needs one instance. Unlike your regular pages with pageBuilder arrays, the blog archive singleton would contain metadata and settings specific to the archive page, while your actual posts are queried dynamically.

What Goes in the Singleton

Your blog archive singleton might look like this:

export const blogArchive = defineType({
  name: 'blogArchive',
  title: 'Blog Archive',
  type: 'document',
  fields: [
    defineField({
      name: 'title',
      type: 'string',
      title: 'Page Title'
    }),
    defineField({
      name: 'description',
      type: 'text',
      title: 'Page Description'
    }),
    defineField({
      name: 'seo',
      type: 'seo', // your SEO object
    }),
    defineField({
      name: 'postsPerPage',
      type: 'number',
      title: 'Posts Per Page',
      initialValue: 10
    }),
    // Optional: featured posts
    defineField({
      name: 'featuredPosts',
      type: 'array',
      of: [{ type: 'reference', to: [{ type: 'post' }] }]
    })
  ]
})

Fetching Posts in Your Frontend

The singleton stores settings, not the posts themselves. You'd query posts separately using GROQ:

// Get the archive settings
const archiveSettings = await client.fetch(`*[_type == "blogArchive"][0]`)

// Get all posts (sorted by date)
const posts = await client.fetch(`
  *[_type == "post"] | order(publishedAt desc) {
    _id,
    title,
    slug,
    excerpt,
    publishedAt,
    author->
  }
`)

Setting Up the Singleton

You'll need to configure your sanity.config.js to make it a proper singleton by customizing the Structure Builder, filtering templates, and limiting document actions. The singleton document guide has the full implementation details, or you can use the singleton-tools plugin for easier setup.

This approach keeps your content architecture clean: regular pages use pageBuilder for flexibility, while the blog archive uses a singleton for configuration + dynamic GROQ queries for the actual post list.