/**
 * Copyright (c) 2026 AzerothJS.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */
/**
 * A strong entity-tag for `value` within `scope`.
 *
 * FNV-1a over the serialized body: an ETag has to change when the bytes change and nothing more,
 * so a cryptographic hash would only cost time. The length is folded in as a cheap second
 * dimension against collisions.
 */
export declare function etagFor(value: unknown, scope: string): string;
/** Whether the client's `If-None-Match` still covers `etag`. */
export declare function matchesEtag(ifNoneMatch: string | null, etag: string): boolean;
/**
 * Options for {@link conditional}. `scope` is REQUIRED and it is the security half of the
 * ETag: the tag hashes scope + body, so two principals with different views of one URL can
 * never validate each other's cached copy. Omitting a per-principal scope is a cross-tenant
 * cache leak, which is why there is no default.
 */
export interface ConditionalOptions {
    /**
     * What the response varies by - the account, tenant, or role that produced these rows.
     * REQUIRED: see the module note. Pass a stable string, not a whole object.
     */
    scope: string;
    /** Seconds the client may reuse the response without revalidating (default 0). */
    maxAge?: number;
    /**
     * Whether a SHARED cache (a CDN, a proxy) may store this. Default false, because a scoped
     * response is per-caller by construction. Set true only for genuinely public data.
     */
    shared?: boolean;
}
/**
 * A conditional JSON response: 200 with a validator, or a bodyless 304 when the client's validator
 * still holds.
 *
 * ```ts
 * app.get('/api/orgs/:org/branches', (context) =>
 *     conditional(context.request, { rows }, { scope: String(actor.userId), maxAge: 5 }));
 * ```
 */
export declare function conditional(request: Request, value: unknown, options: ConditionalOptions): Response;