[Workers] Document cf.vary request option

[zaidoon1]

Add Workers Request cf.vary reference docs, a fetch cache example, and a Cache Vary cross-link.

Documentation checklist

• Is there a changelog entry (guidelines)? If you don't add one for something awesome and new (however small) — how will our customers find out? Changelogs are automatically posted to RSS feeds, the Discord, and X.
• The change adheres to the documentation style guide.
• If a larger change - such as adding a new page- an issue has been opened in relation to any incorrect or out of date information that this PR fixes.
• Files which have changed name or location have been allocated redirects.

[cloudflare-docs-bot]

Review

💡 1 suggestion found in commit a352957.

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_{No code review issues found.}

Conventions

Checks PR title, description, and redirect checklist.

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Style Guide Review

Suggestions (1)

File	Issue
workers/examples/cache-using-fetch.mdx line 29	Unused component imports — Imports TabItem and Tabs but neither component tag appears in the patch Fix: Remove TabItem and Tabs from the import if they are not used elsewhere, or use them in the added content

Redirects

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[github-actions]

This pull request requires reviews from CODEOWNERS as it changes files that match the following patterns:

Pattern	Owners
/src/content/changelog/	@cloudflare/pm-changelogs, @cloudflare/product-owners
/src/content/docs/cache/	@cloudflare/product-owners, @ack-cf, @zaidoon1
/src/content/docs/workers/	@cloudflare/workers-docs, @GregBrimble, @irvinebroque, @mikenomitch, @korinne, @WalshyDev, @cloudflare/deploy-config, @cloudflare/product-owners, @cloudflare/wrangler, @MattieTK, @cloudflare/dev-plat-leads, @vy-ton

[ask-bonk]

Review for PR #31754

Summary

This PR adds documentation for the new cf.vary request init option in Workers. It makes three well-targeted changes:

1. src/content/docs/workers/runtime-apis/request.mdx — Adds vary to the RequestInitCfProperties list and introduces a new #### The cf.vary property subsection with full schema details, limits, validation rules, and a JSON example.
2. src/content/docs/workers/examples/cache-using-fetch.mdx — Adds a TypeScriptExample showing how to use cf.vary in a fetch() call.
3. src/content/docs/cache/concepts/vary.mdx — Cross-links from the Cache Vary concept page to the new Workers reference.

Labels to apply

documentation, workers, cache

Issues to address

Severity	Issue	Location
🔴	Misleading statement about supported keys	request.mdx line ~186
🔴	Imprecise shorthand for object property	request.mdx line ~188
🟡	Consider adding a changelog entry	src/content/changelog/

---

Inline suggestions

src/content/docs/workers/runtime-apis/request.mdx — line ~186

"The default object and custom header entries support only action."

This contradicts the table directly above it, which shows accept and accept-language entries also support media_types and languages. Consider clarifying:

The `default` object and most custom header entries support only `action`. The `accept` and `accept-language` entries also support the additional keys listed above.

---

src/content/docs/workers/runtime-apis/request.mdx — line ~188

"For most deployments, set default to bypass..."

default is an object (e.g. { action: "bypass" }), not a string. Consider:

For most deployments, set `default.action` to `bypass`, add entries for expected origin `Vary` headers, and use `normalize` for `accept` and `accept-language` unless your origin requires raw header values.

---

Notes

• Cross-links are correct — all internal links use root-relative paths with trailing slashes (/workers/runtime-apis/request/#the-cfvary-property, /cache/concepts/vary/, etc.).
• Component imports are correct — TypeScriptExample is properly imported in cache-using-fetch.mdx; Type and MetaInfo are already available in request.mdx.
• No MDX syntax issues — no unescaped {, }, <, or > characters in prose.
• Prettier — both request.mdx and cache-using-fetch.mdx fail prettier --check, but this is a pre-existing issue on the production branch and not introduced by this PR.

Question for the author

Since cf.vary is new functionality being documented, should a changelog entry be added in src/content/changelog/workers/ (or cache/) so customers discover it via RSS and Discord? This is item #1 in the PR checklist.

github run

[github-actions]

Preview URL: https://a3529575.preview.developers.cloudflare.com
Preview Branch URL: https://zaidoon-workers-cf-vary-docs.preview.developers.cloudflare.com

Files with changes (up to 15)

Original Link	Updated Link
https://developers.cloudflare.com/workers/runtime-apis/request/	https://zaidoon-workers-cf-vary-docs.preview.developers.cloudflare.com/workers/runtime-apis/request/
https://developers.cloudflare.com/changelog/post/2026-06-28-cf-vary-request-option/	https://zaidoon-workers-cf-vary-docs.preview.developers.cloudflare.com/changelog/post/2026-06-28-cf-vary-request-option/
https://developers.cloudflare.com/workers/examples/cache-using-fetch/	https://zaidoon-workers-cf-vary-docs.preview.developers.cloudflare.com/workers/examples/cache-using-fetch/
https://developers.cloudflare.com/cache/concepts/vary/	https://zaidoon-workers-cf-vary-docs.preview.developers.cloudflare.com/cache/concepts/vary/

[irvinebroque]

@vy-ton