@reaatech/multi-tenant-mcp-cost-accounting

Status: Pre-1.0 — APIs may change in minor versions. Pin to a specific version in production.

Track and report per-tenant usage costs with per-call, per-token, and tiered pricing models.

Installation

npm install @reaatech/multi-tenant-mcp-cost-accounting
# or
pnpm add @reaatech/multi-tenant-mcp-cost-accounting

Feature Overview

• Per-call pricing — Assign a flat cost to each tool invocation.
• Per-token pricing — Charge independently for input and output tokens.
• Tiered discounts — Volume discounts applied progressively as call counts grow.
• Usage emitters — Forward UsageEvent records to your billing pipeline via a callback. Emissions are non-blocking and never fail the request.

Quick Start

import {
  DefaultCostCalculator,
  InMemoryCostTracker,
  CallbackUsageEmitter,
} from '@reaatech/multi-tenant-mcp-cost-accounting';

const calculator = new DefaultCostCalculator({
  perCall: { 'tool-premium': 0.05, 'tool-standard': 0.005 },
  perToken: { input: 0.001, output: 0.002 },
  tiers: [
    { upTo: 1000, discount: 0 },
    { upTo: 10_000, discount: 0.1 },
    { upTo: Number.POSITIVE_INFINITY, discount: 0.2 },
  ],
});

const tracker = new InMemoryCostTracker({ calculator });

const emitter = new CallbackUsageEmitter(async (event) => {
  await billingPipeline.record(event);
});

const event = {
  tenantId: 'acme-corp',
  itemName: 'tool-premium',
  itemType: 'tool',
  inputTokens: 1500,
  outputTokens: 800,
  timestamp: new Date(),
};

const cost = calculator.calculate(event, tracker.getAccount('acme-corp'));
await tracker.record(event); // accumulates into the tenant's CostAccount

Exports

| Export | Kind | Description | |--------|------|-------------| | CostCalculator | Interface | calculate(event, account) → number | | CostTracker | Interface | record(event) + getAccount(tenantId) | | UsageEventEmitter | Interface | emit(event) — async, non-blocking | | CostAccount | Interface | tenantId, totalCost, totalCalls, totalInputTokens, totalOutputTokens | | UsageEvent | Interface | Event payload: tenantId, itemName, itemType, inputTokens, outputTokens, timestamp | | DefaultCostCalculator | Class | Per-call + per-token + tiered cost calculation | | InMemoryCostTracker | Class | LRU-bounded in-memory cost accumulator | | CallbackUsageEmitter | Class | Invoke a user callback for each usage event |

Pricing Evaluation Order

1. Per-call cost (pricing.perCall[itemName])
2. Per-token cost (pricing.perToken.input × count + pricing.perToken.output × count)
3. Tiered discount applied to the subtotal based on account.totalCalls

Related Packages

• @reaatech/multi-tenant-mcp-types
• @reaatech/multi-tenant-mcp-middleware

License

MIT