When you make too many calls to a particular product line, you'll get a "too many requests" 429 error. The number of calls you can make per day depends on your plan. Check your plan for the call limits per product. In some cases, the limit is applied on an hourly basis, so for example, a limit of 500,000 calls/day becomes 21,000 calls/hour. If you think you're ready for an upgrade, submit an upgrade request by going to your Account section. Our governance team will review it and get back to you with a decision.