Yes, we do, but we are very generous with the limits, only triggering if an API Key is used to send more than 10 requests a second.
In reality, we would not expect a customer to come anywhere near that limit, but if they do we will return a 429 error on requests that go over this limit.
For example if you send 15 requests in one second, you should expect to receive 10 success messages and 5 failures.
This is not a lasting block and it is cleared the next second.
Generally a good way to avoid getting a 429 is to send your calls sequentially and not multi-thread the requests.
If you feel you need more bandwidth than that, please email support@vworkapp.com so that we can discuss your requirements.