This topic describes common parameters.

Common parameters include common request parameters and common response parameters.

Common request parameters

The following table describes the common request parameters that are included in a URL for a GET request.

Parameter Type Required Description
Action String Yes The operation that you want to perform.
AccessKeyId String Yes The AccessKey ID provided to you by Alibaba Cloud. The AccessKey pair is used to call API operations for authentication, similar to how the user password is used to log on to the Auto Scaling console. For more information, see Create an AccessKey.
Signature String Yes The signature string of the current request. For more information about how signatures are calculated, see Signatures.
SignatureMethod String Yes The encryption method of the signature string. Set the value to HMAC-SHA1.
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.
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, 20:00:00 on January 1, 2018 (UTC+8) is written as 2018-01-01T12:00:00Z.

Version String Yes The version number of the API. The value must be in the YYYY-MM-DD format. Set the value to 2014-08-28.
Format String No The format in which to return the response. Valid values: JSON and XML. Default value: JSON.

Examples

https://ess.aliyuncs.com/?Action=XXXXXX
&Format=xml
&Version=2014-08-28
&Signature=Pc5WB8gokVn0xfeu%2FZV%2BiNM1dg****
&SignatureMethod=HMAC-SHA1
&SignatureNonce=1521552885****
&SignatureVersion=1.0
&AccessKeyId=key-test
&Timestamp=2018-01-01T12:00:00Z
...

Common response parameters

Parameter Type Description
RequestId String The ID of the request. This parameter is returned regardless of whether the call is successful.