# Headers

You must supply a set of HTTP headers when making a request. These headers can include both standard HTTP headers and custom OCTO API or Ventrata headers.

Below are the required standard request headers, custom headers we recommend using, and useful headers you can expect in Ventrata responses.

## Request Headers

| Header              | Required    | Description                                                                                                                                                                                                                                                                                                                                                                                                      |
| ------------------- | ----------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `Authorization`     | Required    | Your [Authentication](https://docs.ventrata.com/getting-started/getting-started) `Bearer` token.                                                                                                                                                                                                                                                                                                                 |
| `Content-Type`      | Required    | Must be `application/json` for all `POST`, `PATCH`, and `DELETE` requests.                                                                                                                                                                                                                                                                                                                                       |
| `Octo-Capabilities` | Required    | A list of [Capabilities](https://docs.ventrata.com/getting-started/request-capabilities) to include in the response, for example `Octo-Capabilities: octo/pricing, octo/content`. Include the header but leave it empty if no capabilities are needed. If this header is not included, Ventrata returns a `400` error.                                                                                           |
| `Octo-Env`          | Recommended | This can mark any booking performed with live credentials as a test sale in Ventrata. This means it will not consume availability, barcodes will not work, and you will not be invoiced. Use `Octo-Env: test` for test bookings and `Octo-Env: live` to turn it off and sell live. See [Live Testing](https://docs.ventrata.com/test-credentials#live-testing).                                                  |
| `Accept-Language`   | Optional    | This conforms to the regular HTTP specification for language. If the supplier has translated their content, it returns content in the specified language when possible, and error messages are also translated. For example, send `Accept-Language: fr` and the server responds with `Language: fr` when that language is available. See [Localization](https://docs.ventrata.com/getting-started/localization). |

## Response Headers

| Header                     | Description                                                                                                                                                                                                                                               |
| -------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `Content-Type`             | `application/json`                                                                                                                                                                                                                                        |
| `Octo-Capabilities`        | A list of [Capabilities](https://docs.ventrata.com/getting-started/request-capabilities) initialized with your request, for example `Octo-Capabilities: octo/pricing, octo/content`.                                                                      |
| `Octo-Env`                 | Returns `test` if the request is in test, or `live` if it is not, depending on your request `Octo-Env` value and whether the supplier forced your connection to `test` mode. See [Live Testing](https://docs.ventrata.com/test-credentials#live-testing). |
| `Content-Language`         | The language of returned content. See [Localization](https://docs.ventrata.com/getting-started/localization) for how to set it.                                                                                                                           |
| `Octo-Available-Languages` | A list of languages the supplier has translated content into. See [Localization](https://docs.ventrata.com/getting-started/localization).                                                                                                                 |