Metering & Billing
Taking a payment is the easy part of charging customers. The hard part is knowing what each one owes, and stopping what they have not paid for — and that is done for you: every call is metered to the customer and the operation, and quotas are enforced as it happens. Your payment provider only has to take the money.
Apiway meters API consumption using Resource Units (RU) — a configurable cost unit assigned per operation. The gateway tracks consumption in real time; the cost centre aggregates it into financial reports.
How RU Metering Works
Section titled “How RU Metering Works”Each API operation has an RU cost. When a consumer calls an operation, the gateway:
- Deducts the RU cost from the subscription’s quota
- Buffers the consumption event in memory
- Flushes events to the RU Service in background batches
- Returns RU headers on the response
Response Headers
Section titled “Response Headers”Every metered response includes consumption information:
| Header | Description |
|---|---|
X-RU-Limit | Total RU quota for this subscription |
X-RU-Remaining | RU remaining in the current period |
X-RU-Cost | RU cost of this specific request |
X-RU-Value | Monetary value of this request |
X-RU-Consumed | Total RU consumed in the current period |
X-RU-Period | Billing period (Daily, Monthly, Quarterly, Annual) |
X-RU-Currency | Currency code for the value |
X-RU-Alert-Threshold | Percentage threshold for soft alerts |
Configuring RU Costs
Section titled “Configuring RU Costs”RU costs are set per operation when defining the API:
- Default cost — Applied to all operations unless overridden
- Per-operation cost — Override for specific operations (e.g., a complex query might cost 5 RU while a simple GET costs 1 RU)
- Monetary value — Each RU maps to a currency value
OpenSLA Tiers
Section titled “OpenSLA Tiers”OpenSLA definitions can specify different RU allocations per tier:
| Tier | RU Quota | RU Period | Price per RU |
|---|---|---|---|
| Free | 1,000 | Monthly | Free |
| Standard | 50,000 | Monthly | 0.001 USD |
| Enterprise | Unlimited | Monthly | 0.0005 USD |
Subscription Quotas
Section titled “Subscription Quotas”Each subscription has an RU quota and billing period:
| Period | Reset Cycle |
|---|---|
| Daily | Midnight UTC |
| Monthly | 1st of each month |
| Quarterly | Every 3 months |
| Annual | Yearly |
| Pay-as-you-go | No quota — unlimited consumption, billed on usage |
Quota Enforcement
Section titled “Quota Enforcement”| Event | Effect |
|---|---|
| Threshold reached | Soft alert — notification sent, calls continue |
| Quota exhausted | Hard stop — gateway returns 402 Payment Required |
| Recurring breaches | 3+ breaches in 30 days triggers SLA tier upgrade recommendation |
Cost Centre
Section titled “Cost Centre”The cost centre provides financial reporting across your API portfolio:
- Revenue — RU consumed by subscribers of your APIs (you earn)
- Cost — RU you consume from external APIs (you pay)
- Margin — Revenue minus cost, per API
- Portfolio P&L — Aggregate financial position across all APIs
The Wealth Engine surfaces negative-margin APIs — ensuring every produced API is value-add.
Accessing Metering Data
Section titled “Accessing Metering Data”curl https://ru.api.apiway.net/v1/ru/consumption \ -H "Authorization: Bearer $TOKEN"curl -N https://risk.api.apiway.net/v1/events/subscribe \ -H "Authorization: Bearer $TOKEN" \ -H "Accept: text/event-stream"Navigate to Home to see the KPI dashboard, or Cost Centre for detailed financial reports.