You can specify and enforce a maximum numbers of calls per day for each REST API consumer by configuring the Custom Allocations > Max calls per day setting under the Consumer Properties section. This can help prevent a consumer from using up API calls that need to be available for other consumers.
You can also see the per-day call limit for your account (2000 in this example,) and the total calls allocated to all consumers (300). Once the calls are assigned, consumer cannot exceed the limit. The API will return a "quota exceeded" error to any requests sent after the limit is reached, until it resets the next day.
User privileges
To configure this setting, you must have Manage API settings enabled for your contact user role.
