Ограничивайте каждую ветвь и весь run

import type { BudgetLimits, BudgetSnapshot, Usage } from "./types.js";

export class BudgetExceededError extends Error {
  public constructor(message: string) {
    super(message);
    this.name = "BudgetExceededError";
  }
}

export class BudgetLedger {
  readonly #limits: BudgetLimits;
  #usedCalls = 0;
  #usedTokens = 0;
  #usedCostUnits = 0;
  #usedSimulatedLatencyMs = 0;

  public constructor(limits: BudgetLimits) {
    this.#limits = limits;
  }

  public consume(usage: Usage): void {
    const next = {
      calls: this.#usedCalls + usage.calls,
      tokens: this.#usedTokens + usage.tokens,
      costUnits: this.#usedCostUnits + usage.costUnits,
      latency: this.#usedSimulatedLatencyMs + usage.simulatedLatencyMs
    };

    if (next.calls > this.#limits.maxCalls) {
      throw new BudgetExceededError("Agent call budget exceeded");
    }
    if (next.tokens > this.#limits.maxTokens) {
      throw new BudgetExceededError("Token budget exceeded");
    }
    if (next.costUnits > this.#limits.maxCostUnits) {
      throw new BudgetExceededError("Cost budget exceeded");
    }
    if (next.latency > this.#limits.maxSimulatedLatencyMs) {
      throw new BudgetExceededError("Latency budget exceeded");
    }

    this.#usedCalls = next.calls;
    this.#usedTokens = next.tokens;
    this.#usedCostUnits = next.costUnits;
    this.#usedSimulatedLatencyMs = next.latency;
  }

  public remainingCalls(): number {
    return this.#limits.maxCalls - this.#usedCalls;
  }

  public snapshot(): BudgetSnapshot {
    return {
      ...this.#limits,
      usedCalls: this.#usedCalls,
      usedTokens: this.#usedTokens,
      usedCostUnits: this.#usedCostUnits,
      usedSimulatedLatencyMs: this.#usedSimulatedLatencyMs
    };
  }
}