> For the complete documentation index, see [llms.txt](https://arlinear.gitbook.io/documentation/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://arlinear.gitbook.io/documentation/api/base-url-and-authorization.md).

# Base URL and Authorization

Every API request is made to the base URL `https://api.arlinear.com/functions/v1/...`.

The API requires an authorization header with **your API key**. Below is a JavaScript example of how to structure your request:

```javascript
fetch("https://api.arlinear.com/functions/v1/<API Endpoint>", {
  method: "POST",
  headers: {
    Authorization: "<Your API Key>", // Keep this API key a secret!
  },
  body: ...
});
```