GetParameterHistory - Amazon Systems Manager
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Retrieves the history of all changes to a parameter.


If you change the Amazon KMS key alias for the KMS key used to encrypt a parameter, then you must also update the key alias the parameter uses to reference KMS. Otherwise, GetParameterHistory retrieves whatever the original key alias was referencing.

Request Syntax

{ "MaxResults": number, "Name": "string", "NextToken": "string", "WithDecryption": boolean }

Request Parameters

For information about the parameters that are common to all actions, see Common Parameters.

The request accepts the following data in JSON format.


The maximum number of items to return for this call. The call also returns a token that you can specify in a subsequent call to get the next set of results.

Type: Integer

Valid Range: Minimum value of 1. Maximum value of 50.

Required: No


The name or Amazon Resource Name (ARN) of the parameter for which you want to review history. For parameters shared with you from another account, you must use the full ARN.

Type: String

Length Constraints: Minimum length of 1. Maximum length of 2048.

Required: Yes


The token for the next set of items to return. (You received this token from a previous call.)

Type: String

Required: No


Return decrypted values for secure string parameters. This flag is ignored for String and StringList parameter types.

Type: Boolean

Required: No

Response Syntax

{ "NextToken": "string", "Parameters": [ { "AllowedPattern": "string", "DataType": "string", "Description": "string", "KeyId": "string", "Labels": [ "string" ], "LastModifiedDate": number, "LastModifiedUser": "string", "Name": "string", "Policies": [ { "PolicyStatus": "string", "PolicyText": "string", "PolicyType": "string" } ], "Tier": "string", "Type": "string", "Value": "string", "Version": number } ] }

Response Elements

If the action is successful, the service sends back an HTTP 200 response.

The following data is returned in JSON format by the service.


The token to use when requesting the next set of items. If there are no additional items to return, the string is empty.

Type: String


A list of parameters returned by the request.

Type: Array of ParameterHistory objects


For information about the errors that are common to all actions, see Common Errors.


An error occurred on the server side.

HTTP Status Code: 500


The query key ID isn't valid.

HTTP Status Code: 400


The specified token isn't valid.

HTTP Status Code: 400


The parameter couldn't be found. Verify the name and try again.

HTTP Status Code: 400



This example illustrates one usage of GetParameterHistory.

Sample Request

POST / HTTP/1.1 Host: Accept-Encoding: identity Content-Length: 29 X-Amz-Target: AmazonSSM.GetParameterHistory X-Amz-Date: 20180316T005206Z User-Agent: aws-cli/1.11.180 Python/2.7.9 Windows/8 botocore/1.7.38 Content-Type: application/x-amz-json-1.1 Authorization: AWS4-HMAC-SHA256 Credential=AKIAIOSFODNN7EXAMPLE/20180316/us-east-2/ssm/aws4_request, SignedHeaders=content-type;host;x-amz-date;x-amz-target, Signature=39c3b3042cd2aEXAMPLE { "Name": "EC2TestServerType" }

Sample Response

{ "Parameters": [ { "Description": "Instance type for Test servers", "LastModifiedDate": 1521158745.607, "LastModifiedUser": "arn:aws:iam::111122223333:user/Mateo.Jackson", "Name": "EC2TestServerType", "Policies": [], "Type": "String", "Value": "t2.nano", "Version": 1 }, { "Description": "Instance type for Test servers", "LastModifiedDate": 1521158834.467, "LastModifiedUser": "arn:aws:iam::111122223333:user/Mateo.Jackson", "Name": "EC2TestServerType", "Policies": [], "Type": "String", "Value": "t2.micro", "Version": 2 }, { "Description": "Instance type for Test servers", "LastModifiedDate": 1521158912.828, "LastModifiedUser": "arn:aws:iam::111122223333:user/Jane.Roe", "Name": "EC2TestServerType", "Policies": [], "Type": "String", "Value": "t2.large", "Version": 3 } ] }

See Also

For more information about using this API in one of the language-specific Amazon SDKs, see the following: