This topic describes the common request and response parameters.

Common request parameters

The following table describes common request parameters that must be used when you call ROS API operations by sending GET requests over URLs.

Parameter Type Required Description
Action String Yes The operation that you want to perform. For more information about valid values of this parameter, see List of operations by function.
AccessKeyId String Yes The AccessKey ID provided to you by Alibaba Cloud.
Signature String Yes The signature string of the current request. For more information about how signatures are calculated, see Request 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.
Version String Yes The version number of the API. The value must be in the YYYY-MM-DD format. Set the value to 2019-09-10.
Format String No The format in which to return the response. Valid values: json and xml. Default value: xml.

Sample requests

Common response parameters

Parameter Type Description
RequestId String The ID of the request. Every response returns a unique RequestID regardless of whether the call is successful.