Rate limits are based on requests per min and are fully independent of overall credits usage. Going over your credits will not automatically trigger rate limits.
This type of rate limit is triggered when you call the same API above its API-specific threshold on your plan. As an example - On the Growth plan, you can call two different APIs at 500 RPM each for a total RPM of 1000 without triggering your rate limits.
This type of rate limit is triggered when you call any API above the global threshold on your plan./validate, /signer and signer/developer_managed APIs don’t count towards global rate limits.