withastro/astro · error

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

Error message

Skipping cache for ${url.pathname}${url.search} because response includes Set-Cookie.

What it means

During cached-route handling in the Astro experimental route cache memory provider, a response was about to be stored, but hasSetCookieHeader() detected either a literal Set-Cookie header on the Response or at least one cookie appended via Astro's cookies API (AstroCookies). Responses that set cookies are considered user-specific, so caching them would leak per-user data to other visitors; the provider skips caching this URL and logs this warning.

Source

Thrown at packages/astro/src/core/cache/memory-provider.ts:276

	if (!entry.vary || !entry.varyValues) return true;
	for (const header of entry.vary) {
		const requestValue = request.headers.get(header) ?? '';
		if (requestValue !== entry.varyValues[header]) return false;
	}
	return true;
}

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;

View on GitHub (pinned to e294953aa8)

Solutions

1. Remove cookies.set(...) / response Set-Cookie headers from responses you want cached
2. Move personalized logic that sets cookies into middleware or an API route excluded from caching
3. If the cookie is session-related, ensure the cached route does not depend on session state

When it happens

Trigger: Thrown at packages/astro/src/core/cache/memory-provider.ts:276 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/a426b19128a39ad1. Report an issue: GitHub.