# Authentication The **Mews POS API** uses bearer authentication, also known as token authentication. When you make an API call, include your API key in the `Authorization` header in the following format: ``` Bearer ``` `` is a placeholder for your secret key, which should have an `sk_test` prefix for access to the test environment and an `sk_live` prefix for access to the live or production environment. > **Important**: It is important to keep your API keys safe. Do not share your API keys in publicly accessible locations like GitHub or client-side code. All API requests should be made over `HTTPS`, any requests made over `HTTP` will fail. Additionally, API requests that lack authentication will also fail. --- # 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://docs.mews.com/pos-api/guidelines/authentication.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.