Agent Ready HTML

App shell

In short

A near-empty HTML document whose content is injected by JavaScript after load, typically a single div with id root or app. Example: The guide lists an empty app shell beside a 403 as responses that stop fetch-only agents. Related terms: Hydration, Initial HTML, Rendered HTML, Content negotiation, Answer provenance.

Source of the example

The example in the summary above is from vercel.com, read 4 November 2026.

Where it shows up on this site

Neighbouring terms

  • Hydration: The step where client JavaScript attaches event handlers to server-rendered HTML.
  • Initial HTML: The HTML document a server returns for a URL before any JavaScript runs.
  • Rendered HTML: The DOM after a browser has run the page scripts.
  • Content negotiation: The HTTP mechanism where the client states preferred formats in the Accept header and the server picks a representation for the same URL.
  • Answer provenance: Which fetched page an agent answer can be traced to.

Sources

  1. vercel.com https://vercel.com/kb/guide/make-your-site-readable-by-ai-agents, read 4 November 2026

Last reviewed 4 November 2026