By default, if your app executes more than 30 API calls within 10 seconds, the app will be throttled, and you should retry the call later. You will receive the following error response:

Throttling is in place to protect API partners and WePay from attacks and programming errors in an app that can cause infinite loops in API calls. Under normal circumstances an API application should never be throttled.

Please let us know if you anticipate a high API call volume and want the default throttle limits raised for your app.