// Token计数器：跟踪输入/输出 token，月度累计，单次推理成本计算
// Claude-3-Sonnet 价格假设：$3 / 1_000_000 input tokens, $15 / 1_000_000 output tokens
import { config } from './config.js';
export type TokenRecord = {
timestamp: string; // ISO 日期
inputTokens: number;
outputTokens: number;
costUsd: number;
};
export class TokenCounter {
// in-memory store: map from YYYY-MM to { input, output }
private monthlyUsage: Map<string, { input: number; output: number }> = new Map();
// pricing
private inputPricePerMillion = 3; // $3 per 1M input tokens
private outputPricePerMillion = 15; // $15 per 1M output tokens
// hard limit per request (from config.MAX_TOKENS)
public readonly HARD_LIMIT = config.MAX_TOKENS;
recordUsage(inputTokens: number, outputTokens: number, when = new Date()): TokenRecord {
if (inputTokens + outputTokens > this.HARD_LIMIT) {
throw new Error(`请求超出硬限制: ${this.HARD_LIMIT} tokens`);
}
if (inputTokens < 0 || outputTokens < 0) {
throw new Error("token 数量不能为负数");
}
const monthKey = this.monthKey(when);
const prev = this.monthlyUsage.get(monthKey) ?? { input: 0, output: 0 };
prev.input += inputTokens;
prev.output += outputTokens;
this.monthlyUsage.set(monthKey, prev);
const cost = this.calculateCostFor(inputTokens, outputTokens);
const record: TokenRecord = {
timestamp: when.toISOString(),
inputTokens,
outputTokens,
costUsd: cost,
};
return record;
}
// 计算单次请求成本（美元）
calculateCostFor(inputTokens: number, outputTokens: number): number {
const inputCost = (inputTokens / 1_000_000) * this.inputPricePerMillion;
const outputCost = (outputTokens / 1_000_000) * this.outputPricePerMillion;
// 保持两位小数
return Math.round((inputCost + outputCost) * 100) / 100;
}
// 获取指定月的汇总（YYYY-MM）
getMonthlyUsage(month?: string): { input: number; output: number; costUsd: number } {
const key = month ?? this.monthKey(new Date());
const v = this.monthlyUsage.get(key) ?? { input: 0, output: 0 };
const cost = this.calculateCostFor(v.input, v.output);
return { input: v.input, output: v.output, costUsd: cost };
}
// 重置指定月（便于测试）
resetMonth(month?: string): void {
const key = month ?? this.monthKey(new Date());
this.monthlyUsage.set(key, { input: 0, output: 0 });
}
// 辅助：当前或给定时间的 YYYY-MM
private monthKey(d: Date): string {
const y = d.getUTCFullYear();
const m = d.getUTCMonth() + 1;
return `${y.toString().padStart(4, "0")}-${m.toString().padStart(2, "0")}`;
}
}
export const globalTokenCounter = new TokenCounter();
export default TokenCounter;
