> For the complete documentation index, see [llms.txt](https://fusionauth.io/docs/llms.txt)

# Security

Learn how to run FusionAuth in various cloud environments.

FusionAuth Cloud has a number of protections in place to prevent a DoS attack and keep your services running smoothly.

## Rate Limiting

If you receive `429` response codes or the following message appears, this would indicate the end user, test, or application is making requests in excess of what is considered typical.

![Too Many Requests](https://fusionauth.io/img/docs/cloud/too-many-requests-blocked.png)

Prior to this message you may receive a [CAPTCHA challenge](#captcha).

To prevent either scenario please limit the number of requests you are making over a given time period or [open a support ticket](https://account.fusionauth.io/account/support) to add your static production IP addresses to the FusionAuth Cloud allow list as needed.

### Add an IP Address to the Allowlist

The criteria for adding an IP address to the FusionAuth Cloud allow list:

*   It is static.
*   It is owned by your company, not shared with other companies/resources, such as a CDN.
*   It is associated with a production server (not a developer's laptop).

If the IP addresses meet these conditions, [log a support request](https://account.fusionauth.io/account/support/). The turnaround time for an allow list change is two to three business days.

If you no longer need an IP address on the allow list, please [log a support ticket](https://account.fusionauth.io/account/support/) to remove it.

## CAPTCHA

> **NOTE:** The FusionAuth Cloud CAPTCHA described here is separate from the CAPTCHA configured using [Advanced Threat Detection](https://fusionauth.io/docs/operate/secure/advanced-threat-detection.md) and can only be managed by the FusionAuth team.

When FusionAuth Cloud detects an unusual traffic pattern from a user, that user will receive a CAPTCHA challenge:

![AWS Preamble CAPTCHA.](https://fusionauth.io/img/docs/cloud/aws-captcha-preamble-text.png) ![Puzzle CAPTCHA from AWS.](https://fusionauth.io/img/docs/cloud/aws-captcha-challenge-puzzle.png) ![Roadmap CAPTCHA from AWS.](https://fusionauth.io/img/docs/cloud/aws-captcha-challenge-roadmap.png)

If you encounter a CAPTCHA during manual testing, ensure you have local browser caching enabled. Using browser developer tools to disable caching often leads to CAPTCHA presentation. Consult the documentation for your browser to learn more.