# Signing the request Every request to the API must be signed with the accounts or users API key. Signing the request is obtained by the following pseudo-code: ```javascript method := POST contentMd5 := md5() contentType := the value of the Content-Type header contentSign := {contentMd5}{contentType} date := the date header of the request (i.e. Tue, 03 Apr, 2012 22:23:24 utc) NOTE: if using the IVVY-Date header, this field will be empty requestString := the entire request string used in the request apiVersion := the api version to use ivvyHeaders := Concatenated string of all headers starting with IVVY, removing all the Dashes (-) and underscore (_) characters in the header, in alphabetical order, joined together with the ampersand (&) character initialStringToSign := {method}{contentSign}{date}{requestString}{apiVersion}{ivvyHeaders} stringToSign := lowercase version of the initialStringToSign ``` For example, the following request... ```javascript POST /api/1.0/test?action=ping HTTP/1.0 Host: api.ap-southeast-2.ivvy.com Date: Tue, 03 Apr 2012 22:23:24 UTC Content-MD5: a09f600c77a6dbd947db24c61e8935ca Content-Type: application/json Content-Length: 18 X-Api-Version: 1.0 X-Api-Authorization: IWS {key:signature here} IVVY-Date: 2012-04-03 22:23:24 ``` ```javascript { "example":"body" } ``` … will require the following string to be signed … `posta09f600c77a6dbd947db24c61e8935caapplication/json/api/1.0/test?action=ping1.0ivvydate=2012-04-03 22:23:24` Note the entire string is set to lowercase before signing. Signing is achieved using the HMAC algorithm, using SHA1 encryption. See [HMAC-SHA1](/development-reference/hmac-sha1.md) for further details --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://developer.ivvy.com/getting-started/creating-the-request/signing-the-request.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.