SaaS Metered Billing with Edge
Charge customers when usage crosses a metered threshold
Goal: Automatically charge SaaS customers when their API usage (or any metered resource) exceeds a defined limit. Edge handles the billing decision and payment while your platform handles usage tracking.
What You'll Need
Steps
Create a metered usage item
Edge > Billable Items > New Item. Trigger type. Mode: Threshold, Capture: Charge Immediately, Condition: >=, Threshold: 10000, Price: $50.00. Description: 'When API calls >= 10,000, charge $50 overage'.
Onboard the customer
Create a billing customer with payment method and trigger permissions when they sign up for your SaaS.
Enroll in the metered item
Enroll the billing customer in the metered usage item.
Track usage
Your application tracks API calls per customer at regular intervals.
Fire with the metric
Call the fire endpoint with `metric_value`:
`POST /apis/edge/trigger/fire.php`
`{"billable_item_id": "bi_xxx", "billing_customer_id": "bc_xxx", "metric_value": 10247}`
Edge evaluates: 10,247 >= 10,000? Yes, charges $50. If below threshold, no charge.
Handle the result
Subscribe to `trigger.captured` and `trigger.failed`. On success, log the overage and optionally reset the counter.
Result
Your platform tracks usage, Edge handles billing decisions and payment. Pass the metric, Edge does the rest.
Variations
Tiered overage pricing
Multiple items at different thresholds: 10K = $50, 25K = $100, 50K = $200.
Per-unit pricing with Variable mode
Use Variable mode. Calculate total (excess calls x $0.001) and pass as override_amount.
