import type { CacheScope, DataRequestMode, OperationDescriptor, RequestEnvelope, SelectionPlan } from './types.js';
export declare function isPlainObject(value: unknown): value is Record<string, unknown>;
export declare function stableStringify(value: unknown): string;
export declare function encodeRequestEnvelopeHeader(envelope: RequestEnvelope): string;
export declare function decodeRequestEnvelopeHeader(value: string): RequestEnvelope | null;
export declare function hashString(value: string): string;
export declare function sanitizeSegment(segment: string): string;
export declare function normalizeOrigin(origin: string): string;
export declare function createOperationId(input: OperationDescriptor): string;
export declare function buildScopeKey(scope: CacheScope): string;
export declare function buildQueryKey(input: {
    operationId: string;
    scopeKey: string;
    requestMode?: DataRequestMode;
    requestInput?: unknown;
    selectionPlan?: SelectionPlan;
}): string;