withastro/astro · error

Skipping cache for ${url.pathname}${url.search} because resp

Error message

Skipping cache for ${url.pathname}${url.search} because response includes Vary: ${header}.

What it means

Before serving or storing a cached response, the memory cache provider checks the response's Vary header. When Vary names 'Cookie' or '*' the response cannot be safely reused across requests, because its content depends on request cookies (or, with '*', on arbitrary request headers) that the cache does not differentiate on. warnSkippedVary reports that this URL is skipped from caching for that reason.

Source

Thrown at packages/astro/src/core/cache/memory-provider.ts:282

}

function hasAtLeastOneCookie(cookies: AstroCookies | undefined): boolean {
	return cookies ? !cookies.headers().next().done : false;
}

function hasSetCookieHeader(response: Response): boolean {
	if (response.headers.has('set-cookie')) return true;
	return hasAtLeastOneCookie(getCookiesFromResponse(response));
}

function warnSkippedSetCookie(logger: AstroRuntimeLogger, url: URL): void {
	logger.warn(
		`Skipping cache for ${url.pathname}${url.search} because response includes Set-Cookie.`,
	);
}

function warnSkippedVary(logger: AstroRuntimeLogger, url: URL, header: 'Cookie' | '*'): void {
	logger.warn(
		`Skipping cache for ${url.pathname}${url.search} because response includes Vary: ${header}.`,
	);
}

/**
 * Simple LRU cache backed by a Map (insertion-order iteration).
 * When the cache exceeds `max` entries, the oldest entry is evicted.
 */
class LRUMap<K, V> {
	#map = new Map<K, V>();
	#max: number;

	constructor(max: number) {
		this.#max = max;
	}

	get(key: K): V | undefined {
		const value = this.#map.get(key);

View on GitHub (pinned to e294953aa8)

Solutions

1. Remove the 'Vary: Cookie' (or 'Vary: *') header from the response so it can be cached
2. Serve cookie-dependent variants from an uncached API route or middleware instead
3. Restrict cookie-dependent rendering to routes excluded from cache caching

When it happens

Trigger: Thrown at packages/astro/src/core/cache/memory-provider.ts:282 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of withastro/astro@e294953aa8 (2026-09-09). Data as JSON: /api/errors/e69974d6898b5643. Report an issue: GitHub.