> For the complete documentation index, see [llms.txt](https://docs.sendstackhq.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.sendstackhq.com/the-basics/rate-limiting.md).

# Rate Limiting

**Overview**

Sendstack API endpoint implements rate limits specifically for failed requests. These limits are designed to enhance security measures and ensure system stability.

**Rate Limit Configuration**

The rate limit for failed authentication requests is configured as follows:

* **Window Period:** 15 minutes
  * Description: The time frame during which the rate limit is applied.
* **Maximum Failed Requests:** 20
  * Description: The maximum number of failed requests allowed within the specified window period.

Exceeding 20 failed requests within a 15-minute window will result in an HTTP 429 (Too Many Requests) response.