Billing

• Billing / Invoice / Payment
• Usage + Metering + Rating + Pricing
• Metering
  • 原始 -> 聚合 + 拆分

Product / SKU
      │
      ├──── Price / Contract / Price Version
      │
      ▼
Raw Usage Event
      │
      ▼
Normalization
      │
      ▼
Metering
      │
      ▼
Billable Quantity
      │
      ▼
Rating  ← Price
      │
      ▼
Charge
      │
      ▼
Billing
      │
      ▼
Invoice
      │
      ▼
Payment

• 客户
• 供应商

UsageEvent {
  id

  // identity
  accountId
  requestId

  // what was consumed
  productId
  skuId

  // when
  eventTime
  receivedAt

  // measurements
  quantities: {
    requests: 1,
    input_tokens: 10000,
    cached_input_tokens: 8000,
    output_tokens: 2000
  }

  // dimensions
  dimensions: {
    model: "claude-sonnet-4.5",
    service_tier: "...",
    region: "...",
  }

  source
  sourceEventId
}