Usage Credits and Call Costs

How we calculate usage credits

Usage Credits

Your account plan includes a monthly allowance of usage credits.

Usage credits are consumed as you make calls to our service during a calendar month and your allowance is replenished at midnight UTC at the start of the following calendar month.

Each API call to our platform incurs a cost in usage credits, detailed below.

Monitoring Usage

We offer a /usage end point by which you can query actual usage credits and call volume for your account.

Additionally, you can view usage charts by signing into your account on our website.

Usage Alerts

If you exceed 100% of your usage credits, your API keys may stop functioning until such time as you upgrade your plan or until the start of the next calendar month.

If you exceed your usage allowance, we'll contact you at your account email address to let you know prior to taking any action against your account (except where the rate of usage is such that it adversely affects our ability to operate the platform and/or our operating costs, in which circumstances we may limit your ability to make calls to the service without prior notice).

🚧 We plan to add the option to receive alerts via email when your monthly usage reaches one or more thresholds (e.g. 50%, 80%, 90%).

Call Costs

Each API end point has an associated base 'cost', which may be modified by the parameters used for the call (e.g. requesting 100 Moon positions is more expensive than requesting just 10).

Additionally, for calls which generate a JSON response (excluding GeoJSON), the actual cost of the call is generally included in the response.

The following table sets out the base cost by end point, together with additional cost factors.

Endpoint	Base Cost	Cost Factors
/version	0
/usage	3
/julian-day	0.5
/date	0.5
/delta-t	0.5
/rise-transit-set	3	Days, Bodies
/az-alt-search	5	Days, Bodies
/celestial-events	10	Bodies, Circumstances (×1.5), Overflow (×1.2)
/meteor-showers	1	Meteor Showers
/body-position	1	Bodies, Days, Interval (points per day)
/geodesic	1	Points, Elevation (×2)
/elevation	1	Points
/bounding-tiles	1
/sightline	3	Points
/lunar-libration	1
/lunar-limb	10
/solar-eclipse/catalog	1 TBC
/solar-eclipse/elements	1 TBC
/solar-eclipse/path	10 TBC	Points
/solar-eclipse/local-circumstances	20 TBC
/insolation/solar-intensity	1
/insolation/irradiance	2	Days, Interval (points per day)
/insolation/daily	3	Days, Interval (points per day)
/insolation/monthly	3	Days, Interval (points per day)

Determining the Cost of Call

For any Radiant Drift API, you can determine the cost of a call without consuming any usage credits by appending the cost=1 query parameter to the URL.

Examples

Body Position

• A call for just the Sun at a single time will cost 1 usage credit

• A call for Sun and Moon at a single time will cost 2 usage credits

• A call for the Sun and Moon for a period of an hour with points for every minute will cost 118 credits (2 * 60)