Common parameters - - Alibaba Cloud Documentation Center

Common request parameters

Common request parameters must be included in all LinkVisual API requests.

Parameter	Type	Required	Description
Format	String	No	The format in which to return the response. Valid values: JSON and XML. Default value: XML.
Version	String	Yes	The version number of the API. The value must be in the `YYYY-MM-DD` format. The latest version is `2018-01-20`. Each API has multiple versions.
AccessKeyId	String	Yes	The AccessKey ID provided to you by Alibaba Cloud. To obtain the AccessKey ID, log on to the Alibaba Cloud Management Console, move the pointer over the profile picture, and then select AccessKey Management. On the AccessKey Pair page, you can view or create AccessKey pairs.
Signature	String	Yes	The signature string of the current request.
SignatureMethod	String	Yes	The encryption method of the signature string. Set the value to HMAC-SHA1.
Timestamp	String	Yes	The timestamp of the request. Specify the time in the ISO 8601 standard in the `YYYY-MM-DDThh:mm:ssZ` format. The time must be in UTC. For example, you can set the parameter to `2016-01-04T12:00:00Z`, which indicates January 4, 2016 20:00:00 UTC+8.
SignatureVersion	String	Yes	The version of the signature encryption algorithm. Set the value to 1.0.
SignatureNonce	String	Yes	A unique, random number used to prevent replay attacks. You must use different numbers for different requests.
RegionId	String	Yes	The region where your devices reside. The region you specify must match the region that is specified in the console. Example: `ap-northeast-1`.

Examples

https://linkvisual.ap-northeast-1.aliyuncs.com/
?Format=XML
&Version=2018-01-20
&Signature=Pc5WB8****
&SignatureMethod=HMAC-SHA1
&SignatureNonce=15215528852396
&SignatureVersion=1.0
&AccessKeyId=...
&Timestamp=2016-01-04T12:00:00Z
&RegionId=ap-northeast-1

Common response parameters

API responses use the HTTP response format where a 2XX status code indicates a successful call and a 4XX or 5XX status code indicates a failed call. Responses can be returned in either the JSON or XML format. You can specify the response format in the request. The default response format is XML.

Every response returns a unique RequestId regardless of whether the call is successful.

Sample success responses

XML format

<? xml version="1.0" encoding="UTF-8"? > 
<!--Root node of the response-->
<Operation name+Response>
    <!--Return request tag-->
    <RequestId>4C467B38-3910-447D-87BC-AC049166F216</RequestId>
    <!--Response result data-->
</Operation name+Response>

JSON format

{
    "RequestId": "4C467B38-3910-447D-87BC-AC049166F216"
    /* Response result data */
}

Sample error responses
If an error occurs when you call an API operation, no result is returned. You can use the error code to identify the cause.
If an error occurs when you call an API operation, a 4XX or 5XX HTTP status code is returned. The response body contains the specific error code and error message. It also contains a globally unique request ID (RequestId). If you cannot confirm what error occurs, contact Alibaba Cloud customer service or submit a ticket. You must provide your request ID for assistance.
- XML format
```
<? xml version="1.0" encoding="UTF-8"? >
<Error>
   <RequestId>8906582E-6722-409A-A6C4-0E7863B733A5</RequestId>
   <Code>UnsupportedOperation</Code>
   <Message>The specified action is not supported. </Message>
</Error>
```
- JSON format
```
{
    "RequestId": "8906582E-6722-409A-A6C4-0E7863B733A5",
    "Code": "UnsupportedOperation",
    "Message": "The specified action is not supported."
}
```