> For the complete documentation index, see [llms.txt](https://docs.coldstack.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.coldstack.io/http-api-compatible-with-amazon-s3/api-reference/common-request-headers.md).

# Common request headers

| Heading                | Description                                                                                                                                                                                                                                                                                                                                                                     |
| ---------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `Authorization`        | <p>Any request to ColdStack must be authorized.<br><br>Along with this heading <code>Date</code>, either a heading or a heading must be used <code>x-amz-date</code>.<br><br>Read about the authorization methods in the corresponding sections of the manual.</p>                                                                                                              |
| `Cache-Control`        | A set of directives for caching data according to [RFC 2616](https://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.9) .                                                                                                                                                                                                                                                 |
| `Content-​Disposition` | The name under which Object Storage will offer to save the object as a file when unloading. [RFC 2616](http://www.w3.org/Protocols/rfc2616/rfc2616-sec19.html#sec19.5.1) compliant .                                                                                                                                                                                            |
| `Content-Encoding`     | Defines the encoding of the content according to [RFC 2616](https://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.11) .                                                                                                                                                                                                                                                 |
| `Content-Length`       | <p>The length of the request body (without headers) in accordance with <a href="https://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.13">RFC 2616</a> .<br><br>The header is required for all requests that transfer any data to Object Storage, for example, when loading an object.</p>                                                                              |
| `Content-Type`         | <p>The data type in the request. Eg <code>text/html</code>. For more information about data types, see the Wikipedia article <a href="https://ru.wikipedia.org/wiki/%D0%A1%D0%BF%D0%B8%D1%81%D0%BE%D0%BA_MIME-%D1%82%D0%B8%D0%BF%D0%BE%D0%B2">List of MIME Types</a> .<br><br>Set by default <code>binary/octet-stream</code>.</p>                                              |
| `Content-MD5`          | <p>128-bit MD5 hash of the request body, encoded <code>base64</code>.<br><br>Compliant with <a href="http://www.ietf.org/rfc/rfc1864.txt">RFC 1864</a> specification .<br><br>Object Storage uses a header to ensure that the data sent matches the received data.</p>                                                                                                          |
| `Date`                 | <p>The date and time the request was sent.<br><br>Format: <code>Thu, 18 Jan 2018 09:57:35 GMT</code>.<br><br>When set <code>x-amz-date</code>, Object Storage ignores the header <code>Date</code>.</p>                                                                                                                                                                         |
| `Expect`               | <p>Expected code <code>100-continue</code>.<br><br>When loading data into Object Storage, an application can use the following logic:<br>- Send a request without a body, but with the Expect: 100-continue header set.<br>- Send a request with a body after receiving a response <code>100-continue</code>. This request <code>Expect</code>should not contain a header .</p> |
| `Expires`              | The expiration date of the answer. [RFC 2616](https://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.21) compliant .                                                                                                                                                                                                                                                     |
| `Host`                 | <p>The receiving host of the request.<br><br>The header is required for HTTP / 1.1, but optional for HTTP / 1.0 requests.</p>                                                                                                                                                                                                                                                   |
| `x-amz-date`           | <p>Date and time at the source of the request.<br><br>Format: <code>Thu, 18 Jan 2018 09:57:35 GMT</code>.<br><br>When set <code>x-amz-date</code>, Object Storage ignores the header <code>Date</code>.</p>                                                                                                                                                                     |