# 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) --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://api.circle.so/apis/headless/usage-and-limits.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.