@Forest_Parks Thanks for coming to the Community for help! We’re presently working on some great documentation around quotas that will help answer your questions. In the meantime, here are some excerpts I hope you will find useful.
Regardless of quotas, I would recommend keeping your system loosely coupled with Infusionsoft in this situation, using a intermediary queue of some sort. (Here’s one of results Google returned when I did a search
[You are limited to] 125,000 [OAuth-authorized API calls] a day, reset at midnight GMT and 25 API calls every second.
Every successful API call and many failed API calls will return exactly where you are on the daily limit and the per second limit.
Example (from Mashery):
X-Plan-Quota-Reset: Saturday, July 30, 2016 12:00:00 AM GMT
The developer application owner receives an email at 65% of the daily usage and 100% of the daily usage as well as 100% of the per second usage.
If more API calls are found to be needed, [we may] be able to extend the limit temporarily …, let us know what you [need] and create a support case.