Workers fetch requests now support cf.vary

Workers fetch() requests now support the cf.vary request option. Use cf.vary to control how Cloudflare caches origin responses with a Vary header for a single subrequest.

src/index.jsjs

export default {
	async fetch(request) {
		return fetch(request, {
			cf: {
				vary: {
					default: { action: "bypass" },
					headers: {
						accept: {
							action: "normalize",
							media_types: ["text/html", "application/json"],
						},
						"accept-language": {
							action: "normalize",
							languages: ["en", "fr", "de"],
						},
					},
				},
			},
		});
	},
};

src/index.tsts

export default {
	async fetch(request): Promise<Response> {
		return fetch(request, {
			cf: {
				vary: {
					default: { action: "bypass" },
					headers: {
						accept: {
							action: "normalize",
							media_types: ["text/html", "application/json"],
						},
						"accept-language": {
							action: "normalize",
							languages: ["en", "fr", "de"],
						},
					},
				},
			},
		});
	},
} satisfies ExportedHandler;

For more information, refer to cf.vary.