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

# Rate Limiting

> Understand how Antei applies rate limits to protect performance and ensure fair usage.

<Icon icon="wave-pulse" size={26} color="#4B5563" />

To maintain system reliability and provide a fair experience across users, Antei enforces strict rate limits across its API. These limits vary slightly between the **Live** and **Sandbox** environments.

***

### Live Environment Limits

| API Group                                               | Rate Limit                   |
| :------------------------------------------------------ | :--------------------------- |
| `/v1/tax/rate`, `/v1/tax/id-validate`, `/v1/tax/unify`  | **1000 requests per minute** |
| Other endpoints (e.g., `/customers`, `/invoices`, etc.) | **300 requests per minute**  |

These limits apply **per API key, Org, User, IP Address**, across all paid plans.

***

### Sandbox Environment Limits

| API Group                                              | Rate Limit                   |
| :----------------------------------------------------- | :--------------------------- |
| `/v1/tax/rate`, `/v1/tax/id-validate`, `/v1/tax/unify` | **30 requests per minute**   |
| Other endpoints (e.g., `/customers`, `/invoices`)      | **Not available in sandbox** |

Sandbox is intended for testing and development. It enforces tighter limits to simulate real-world constraints and prevent abuse.

***

### Response Headers

Each API response returns rate limit headers so you can monitor usage:

| Header                  | Description                                  |
| :---------------------- | :------------------------------------------- |
| `X-RateLimit-Limit`     | Max allowed requests per minute              |
| `X-RateLimit-Remaining` | Remaining calls in the current window        |
| `X-RateLimit-Reset`     | Time (Unix epoch) when the rate limit resets |

```json Response theme={null}
{ "X-RateLimit-Limit": 1000,
"X-RateLimit-Remaining": 846,
"X-RateLimit-Reset": 1717061820 }
```

***

### Exceeding Limits

When you exceed the limit:

* You’ll receive a `429 Too Many Requests` error
* The response will include a helpful message
* Headers will guide retry timing

**Retry-After** headers may be included to indicate how long to wait before retrying.

***

## Best Practices

<Check>Cache tax results wherever possible</Check>
<Check>Use exponential backoff on 429 errors</Check>
<Check>Monitor rate limit headers programmatically</Check>

***

## Need More?

For higher throughput or enterprise needs, contact [support@antei.com](mailto:support@antei.com) with your expected volume and use case.