> ## Documentation Index
> Fetch the complete documentation index at: https://zeply.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Rate Limiting

> Understand rate limits, burst quotas, and headers across Sayvy AI endpoints

# Rate Limiting

To guarantee low audio latency and 99.99% uptime across our real-time voice infrastructure, Sayvy AI enforces rate limits on REST API requests and concurrent voice audio sessions.

***

## Tier Rate Limits

| Plan Tier            | REST Requests / Minute   | Concurrent Outbound Calls | Webhook Delivery Rate |
| :------------------- | :----------------------- | :------------------------ | :-------------------- |
| **Developer / Free** | 60 req / min             | 2 concurrent streams      | 10 events / sec       |
| **Growth**           | 600 req / min            | 25 concurrent streams     | 100 events / sec      |
| **Enterprise**       | Custom (10,000+ req/min) | 500+ concurrent streams   | Unlimited / Dedicated |

***

## Rate Limit Headers

Every HTTP response from Sayvy AI includes headers describing your current quota status:

| Header                  | Description                                                                        |
| :---------------------- | :--------------------------------------------------------------------------------- |
| `X-RateLimit-Limit`     | The maximum number of requests allowed in the current time window.                 |
| `X-RateLimit-Remaining` | The number of remaining requests allowed in the current time window.               |
| `X-RateLimit-Reset`     | Unix epoch timestamp (in seconds) indicating when the current quota window resets. |
| `Retry-After`           | Included only when rate-limited. The number of seconds to wait before retrying.    |

```http theme={null}
HTTP/1.1 200 OK
Content-Type: application/json
X-RateLimit-Limit: 600
X-RateLimit-Remaining: 582
X-RateLimit-Reset: 1788448860
```

***

## Handling 429 Responses

When rate limits are exceeded, Sayvy AI responds with HTTP status code `429 Too Many Requests`:

```json theme={null}
{
  "error": {
    "code": "rate_limit_exceeded",
    "message": "Too many requests. Please throttle your traffic and retry after 2 seconds.",
    "type": "rate_limit_error",
    "retry_after": 2
  }
}
```

### Implementing Exponential Backoff with Jitter

To reliably recover from rate limits, implement exponential backoff with full jitter in your client code:

```typescript theme={null}
async function fetchWithRetry(url: string, options: RequestInit, retries = 5, backoff = 500) {
  try {
    const res = await fetch(url, options);

    if (res.status === 429 && retries > 0) {
      const retryAfter = Number(res.headers.get('Retry-After')) * 1000 || backoff;
      // Add random jitter between 0ms and 200ms
      const jitter = Math.random() * 200;
      await new Promise(r => setTimeout(r, retryAfter + jitter));
      return fetchWithRetry(url, options, retries - 1, backoff * 2);
    }

    return res;
  } catch (err) {
    if (retries > 0) {
      await new Promise(r => setTimeout(r, backoff));
      return fetchWithRetry(url, options, retries - 1, backoff * 2);
    }
    throw err;
  }
}
```

<Tip>
  If your workload requires higher outbound call concurrency or custom burst allowances, contact our team at [enterprise@sayvy.ai](mailto:enterprise@sayvy.ai).
</Tip>