I would like to add metered billing to my solution based on the number of API calls.
I have a pricing model like this:
Basic: 100.000 API Calls / Month
Professional: 500.000 API Calls / Month
API calls that exceed the limit are charged separately, lets say 1€ / 1000 calls.
I was thinking about using metered billing first, but the problem are yearly subscriptions. I do not want to charge the customer every year for the API calls, because this could become very expensive. Instead I would like to create invoices manually for the last month.
But I need the plans over time. Lets say the user starts with the Basic plan and changes to the Professional plan after 15 days. Then I would like to charge the user like this:
Month: April (30 days)
Day 1-15: 200.000 API calls used, limit was 50.000 for this period => additional 150.000 API calls => 150 €
Day 16-30: 200.000 API calls made. Limit was 250.000 => No extra calls needed.
Is it possible to get the "plan-history" with the API or is there another solution for yearly subscriptions?