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

# Authentication

The Paytree API authenticates requests using API keys, which you can view and manage in your back office.

Since your API keys grant access to sensitive functions, it’s important to keep them secure. Never expose your secret API keys in publicly accessible areas like GitHub, client-side code, or similar locations.

All API requests must be made over HTTPS. Requests sent via plain HTTP will be automatically redirected to HTTPS. Additionally, any requests without proper authentication will fail.

### How to authenticate

All requests should have an `Authorization` header followed by `Token` and your API key. For example.

```
Authorization: Token 4040e5f6d2a248b0aa88c4b3c7174899
```