> For the complete documentation index, see [llms.txt](https://api.circle.so/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://api.circle.so/apis/headless/usage-and-limits.md).

# Usage and limits

For Headless APIs, the usage is based on MAUs (Monthly Active Users). \
\
MAU is the number of unique users (with uniqueness defined by the user-ID) that create or consume content on Circle servers through SDK or API within a monthly billing cycle. All service requests except authentication\* are counted as MAU. MAU number is based on per-user instead of per-device, meaning that a user with the same user-ID with multiple devices will be counted as 1 MAU.

### Exceptions

Authentication endpoints are not taken into account, so you can use them without increasing your MAU count. Here's a list of what we consider Auth endpoints:

* /api/v1/headless/access\_token/refresh
* /api/v1/headless/access\_token/revoke
* /api/v1/headless/auth\_token
* /api/v1/headless/refresh\_token/revoke
* /api/headless/v1/cookies
* /session/cookies (cookies redirect URL)