import type { CostEntry, CostBreakdown } from '../../types/index.js';
/**
 * Calculate the cost in USD for the given model and token counts.
 */
export declare function calculateCost(model: CostEntry['model'], tokensInput: number, tokensOutput: number): number;
/**
 * Fire-and-forget. Never blocks the calling tool.
 */
export declare function writeCostEntry(projectPath: string, entry: CostEntry): void;
/**
 * Read all entries, filter by period, and aggregate into a CostBreakdown.
 */
export declare function readBreakdown(projectPath: string, period: 'today' | 'week' | 'month' | 'all', topN?: number): Promise<CostBreakdown>;
//# sourceMappingURL=ledger.d.ts.map