---
type: "raw_signal"
id: "we-just-shipped-support-for-the-ugliest-part-4a76ee"
slug: "we-just-shipped-support-for-the-ugliest-part-4a76ee"
title: "We just shipped support for the ugliest part of HTTP: Vary"
description: "Cloudflare has reportedly shipped support for HTTP `Vary` caching."
retrieval_nugget: "Cloudflare has reportedly shipped support for HTTP `Vary` caching."
observed_at: "2026-09-28"
record_date: "2026-09-28"
date_kind: "observed_at"
why_it_matters: "Cloudflare has reportedly shipped support for HTTP `Vary` caching. The cited account describes the previous constraint: behind Cloudflare caching, a URL that returned HTML for `Accept: text/html` and JSON otherwise could cache the wrong representation. The change makes header-selected representations newly practical to evaluate at the CDN layer."
novelty: "notable"
verification_level: "source-linked"
signal_type: "release"
source_platform: "simonwillison.net"
topics: []
entities: []
related_patterns: []
source_url: "https://simonwillison.net/2026/Sep/23/hn-49823961"
source_urls: ["https://simonwillison.net/2026/Sep/23/hn-49823961"]
schema_version: "newruntime-agent-readable-v0.2"
stable_id: "signal:we-just-shipped-support-for-the-ugliest-part-4a76ee"
status: "published"
visuals: []
editor: {"role":"editor","name":"Andrey Reshetnikov","profile":"https://newruntime.com/owner-profile.md","profile_json":"https://newruntime.com/owner-profile.json","same_as":["https://www.linkedin.com/in/reshetnikov1/","https://t.me/lapetuse"]}
routes: {"html":"https://newruntime.com/signals/we-just-shipped-support-for-the-ugliest-part-4a76ee/","markdown":"https://newruntime.com/signals/we-just-shipped-support-for-the-ugliest-part-4a76ee.md","json":"https://newruntime.com/signals/we-just-shipped-support-for-the-ugliest-part-4a76ee.json"}
---

# We just shipped support for the ugliest part of HTTP: Vary

## Retrieval answer

Cloudflare has reportedly shipped support for HTTP `Vary` caching.

Cloudflare has reportedly shipped support for HTTP `Vary` caching. The cited account describes the previous constraint: behind Cloudflare caching, a URL that returned HTML for `Accept: text/html` and JSON otherwise could cache the wrong representation. The change makes header-selected representations newly practical to evaluate at the CDN layer.

Editor: [Andrey Reshetnikov](https://newruntime.com/owner-profile.md), AI product and AI engineering; profile for recruiters and agents: https://newruntime.com/owner-profile.json

## Continue in the graph

Next records for an agent, linked to their Markdown twins. Replace `.md` with `.json` for structured fields, including `next_reads`.

- collection: [Raw Signals](https://newruntime.com/signals.json): Open every source-linked raw signal.
- collection: [Source Ledger](https://newruntime.com/source-ledger.json): Inspect the public source evidence graph.
- whole graph: [discovery graph](https://newruntime.com/discovery-graph.json) (typed nodes and edges) and [site index](https://newruntime.com/site-index.md)