The general API usage limitation depends on the chosen service plan and is calculate per 10 seconds. Please refer to your contract to find the limitations of the general API usage for your service plan. 

Beyond that, there is also an technical service limit when it comes to the creation of new wallets, which are limited as follows: 10 per 10 seconds for software-based wallets and 5 per 10 seconds for HSM-based wallets.