Fullcontact Rate Limits

FullContact publishes both its default ceiling and the exact response headers it returns, which is the part an agent needs. The signalling is unusual: rather than reject immediately, FullContact DELAYS a request up to 1000ms to keep it inside the configured limit and reports the delay it applied in X-FullContact-RateDelay. A 429 is only returned when the required delay would exceed 1000ms, and that 429 is itself delayed by the maximum latency so the caller can retry immediately and safely.