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

# Authentication

Every request needs your business's Cekat API key. The Open API is available on the Business and Enterprise plans. Generate your key in the Cekat dashboard under **Settings → Developers & API** ([open](https://chat.cekat.ai/developers?section=apikeys)).

Send the key in the `api_key` header:

```
api_key: YOUR_API_KEY
```

Endpoints under `/api/...` also accept the same key as a bearer token (`Authorization: Bearer YOUR_API_KEY`). Endpoints under `/templates...` accept only the `api_key` header, so using `api_key` everywhere is the simplest choice.

Keep the key secret: anyone with it can send messages and spend balance on your account.