Common parameters

Common request parameters

Common request parameters refer to the request parameters that each API requires.


Name Type Required Description
Format String No The format of the returned value. Valid values: JSON and XML. Default value: XML.
Version String Yes The version of the API. Format: YYYY-MM-DD. The current version is 2016-04-08.
AccessKeyId String Yes The Key ID provided by Alibaba Cloud for you to access services.
Signature String Yes The result string of the signature. For more information about how to calculate a signature, see Sign signatures.
SignatureMethod String Yse The mode of the signature. HMAC-SHA1 is supported currently.
Timestamp String Yes The timestamp to request. The format of the date follows the ISO8601 standard and uses UTC time. Format: YYYY-MM-DDThh:mm:ssZ. For example, 2013-08-15T12:00:00Z indicates 20:00:00, Aug 15, 2013, Beijing time.
SignatureVersion String Yes The algorithm version of the signature. The current version is 1.0.
SignatureNonce String Yes The unique random number that is used to prevent network replay attacks. You must use different random numbers for the requests.

? Format=json

Common response parameters

Each time you make a call to an API, the system returns a unique identification code (RequestId), regardless whether the request is successful.

  • Examples
    • Successful response examples
      Returned XML results include information about whether the request is successful and specific scenario information. Examples
        "RequestId": "4C467B38-3910-447D-87BC-AC049166F216",
        /* Returned results
    • Error response examples
      No result is returned after the API call fails. You can find the cause of error according to Error codes. When the HTTP request fails, a status code in the 4xx of 5xx format is returned. The response contains specific error codes and error information. The message body also contains a globally unique RequestId and the HostId of the site you request to access. If you cannot find the cause of the error, contact Alibaba Cloud After-Sales Support and provide the HostId and the RequestId for help.
        "RequestId": "7463B73D-35CC-4D19-A010-6B8D65D242EF",
        "HostId": "",
        "Code": "UnsupportedOperation",
        "Message": "The specified action is not supported."
  • Common error codes

    For more information, see ECS common error codes.