X-Usage-Class and the pricing version shown in X-Pricing-Version.
Account-level limits
Rate limits are enforced per API account, not per API key. All keys on the same account share the same limits.
All API accounts start in Tier 1. Your dashboard is the source of truth for your current effective limits, including any account-specific override.
Tier movement
Higher tiers are designed to limit abuse and protect platform capacity while trusted accounts ramp up. Automatic promotion uses verified paid API credits, days since the first successful paid credit, and current good standing. Promotional or manually granted beta credits do not count toward automatic promotion.
Good standing means the API account is active, billing state is active or low balance, available balance is positive, and there has been no recent chargeback reversal. Tier movement is upward by default; lower limits are an operational action for abuse, payment risk, customer request, or support intervention.
Account-specific overrides
Some accounts may have custom effective limits that differ from the public tier table. Overrides can raise limits for trusted partners or lower limits for abuse mitigation. If your dashboard differs from this guide, use the dashboard value.Rate-limit responses
When you exceed your current effective limit, the API returns HTTP429:
Retry-After when available. Wait at least that many seconds before retrying.
Integration guidance
Use client-side backoff for429 responses and avoid sending parallel bursts beyond your tier. For scheduled jobs, spread requests across the minute instead of sending them all at once.