Overview
Aevum Zenth enforces rate limits and usage quotas to ensure platform stability, fair resource allocation, and security across all API endpoints and services. Limits are applied per API key, per organization, or per endpoint depending on the service tier.
Rate limits are calculated using a sliding 24-hour window and calendar month quotas. Exceeding limits returns HTTP 429 (Too Many Requests) with standardized retry headers. Enterprise and Sovereign tiers support custom overrides and dedicated infrastructure.
Tier Limits
Usage caps vary by subscription tier. All limits are subject to change with 30 days notice. Overage options are available for eligible tiers.
| Limit Type | Sandbox / Dev | Business | Enterprise | Sovereign / Custom |
|---|---|---|---|---|
| API Requests / Day | 1,000 | 50,000 | 500,000 | Unlimited (Negotiated) |
| Concurrent Connections | 50 | 500 | 5,000 | Dedicated Pool |
| Data Storage Quota | 10 GB | 1 TB | 10 TB | Custom Allocation |
| Bandwidth / Month | 100 GB | 2 TB | 20 TB | Unmetered |
| Webhook Deliveries / Day | 5,000 | 100,000 | 1,000,000 | Custom |
| Burst Allowance | 1.2x (30s) | 1.5x (60s) | 2.0x (120s) | Configurable |
Technical Implementation
Response Headers
All API responses include standardized rate limit headers to help clients track consumption and implement backoff strategies:
X-RateLimit-Limit: 50000
X-RateLimit-Remaining: 49987
X-RateLimit-Reset: 1735689600
Retry-After: 42 /* seconds */
HTTP 429 Response Body
When rate limits are exceeded, the API returns a structured JSON response detailing the violation and recommended retry window:
{
"error": {
"code": 429,
"message": "Rate limit exceeded. Please retry after the specified window.",
"details": {
"limit": 50000,
"remaining": 0,
"reset_utc": 1735689600,
"retry_after_sec": 42
}
}
}
Overage & Burst Policies
Burst Allowance: Short-term spikes are permitted up to the tier's burst multiplier. Burst capacity refreshes independently of the daily quota. Excessive burst usage triggers temporary throttling to protect platform stability.
Overage Handling: Business and Enterprise tiers can opt into pro-rated overage billing. When enabled, requests beyond the quota are processed but billed at 2x the base API rate. Without overage enabled, requests return HTTP 429 until the next billing cycle or manual quota increase.
API endpoints hosted in sovereign regions (EU-DE, APAC-SG, NA-US) enforce region-specific quotas. Cross-region requests count against the origin region's limit unless explicitly routed through our global load balancer.
Quota Management
Monitor and adjust quotas programmatically via the Quota Management API or through the Developer Portal dashboard.
# GET /api/v2/quota/status
GET /api/v2/quota/status?metric=requests&window=month
# Request quota increase (Enterprise only)
POST /api/v2/quota/request-increase
{
"metric": "requests",
"new_limit": 750000,
"justification": "Seasonal traffic surge"
}
Frequently Asked Questions
Rate limits use a sliding 24-hour window algorithm. Each API key maintains an independent counter that refreshes continuously. Quotas reset at 00:00 UTC on the first day of each calendar month.
Yes. Enterprise customers can request temporary quota increases via the API or support portal. Approvals are typically processed within 24 hours. Sovereign-tier clients have dedicated account managers for real-time adjustments.
Requests are rejected with HTTP 429 until the limit resets. If overage billing is enabled, requests continue but are charged at the overage rate. We recommend implementing exponential backoff and retry logic in your integrations.
Outbound webhook deliveries have a separate quota pool. However, inbound API calls to register, configure, or retry webhooks count against your standard API request limit.