What are the API limits?

Limits are per account, across all of its keys. Every request with a known key counts, including ones that fail. /me is never rate limited, but it still counts toward the month.

The API answers with status 429. The reason field says which limit you reached:

• rate_limit: too many requests in one second. Wait for the Retry-After seconds, then try again.
• monthly_quota: this month's requests are used up. The count resets on the 1st, in UTC.

Requests, under API in the sidebar, shows every call made with your keys and plugin. GET /api/v1/me returns how much of this month's quota is left.