import type { CostEstimate } from '../types/planning.js';
/**
 * Currency and cost-budget enforcement, with no dependency on the model registry.
 *
 * Split out of `optimizer/cost.ts` because enforcing a budget only compares two numbers, while
 * looking a price up needs the 101-model catalogue. Keeping them in one module meant every family
 * that merely enforces a budget — embeddings among them — dragged 30 KB of model data into its
 * import graph to do arithmetic. `optimizer/cost.ts` re-exports everything here, so no public
 * import changes.
 *
 * Distinct from `optimizer/budget.ts`, which enforces *token* budgets on a request before it is
 * sent. This module deals in money after a usage figure exists.
 */
export declare const DEFAULT_CURRENCY = "USD";
/** Raised when a request's estimated cost exceeds its budget. */
export declare class CostBudgetError extends Error {
    constructor(message: string);
}
/** Formats an amount the way `ResponseMeta.estimatedCost` has always presented it. */
export declare function formatCost(amount: number): string;
/** Throws `CostBudgetError` when an estimate exceeds the budget. Does nothing without a budget. */
export declare function assertWithinCostBudget(estimate: CostEstimate, maxEstimatedCost?: number): void;