SSM / Client / get_parameter_history



Retrieves the history of all changes to a parameter.


If you change the 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.

See also: AWS API Documentation

Request Syntax

response = client.get_parameter_history(
  • Name (string) –


    The name of the parameter for which you want to review history.

  • WithDecryption (boolean) – Return decrypted values for secure string parameters. This flag is ignored for String and StringList parameter types.

  • MaxResults (integer) – 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.

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

Return type:



Response Syntax

    'Parameters': [
            'Name': 'string',
            'Type': 'String'|'StringList'|'SecureString',
            'KeyId': 'string',
            'LastModifiedDate': datetime(2015, 1, 1),
            'LastModifiedUser': 'string',
            'Description': 'string',
            'Value': 'string',
            'AllowedPattern': 'string',
            'Version': 123,
            'Labels': [
            'Tier': 'Standard'|'Advanced'|'Intelligent-Tiering',
            'Policies': [
                    'PolicyText': 'string',
                    'PolicyType': 'string',
                    'PolicyStatus': 'string'
            'DataType': 'string'
    'NextToken': 'string'

Response Structure

  • (dict) –

    • Parameters (list) –

      A list of parameters returned by the request.

      • (dict) –

        Information about parameter usage.

        • Name (string) –

          The name of the parameter.

        • Type (string) –

          The type of parameter used.

        • KeyId (string) –

          The ID of the query key used for this parameter.

        • LastModifiedDate (datetime) –

          Date the parameter was last changed or updated.

        • LastModifiedUser (string) –

          Amazon Resource Name (ARN) of the Amazon Web Services user who last changed the parameter.

        • Description (string) –

          Information about the parameter.

        • Value (string) –

          The parameter value.

        • AllowedPattern (string) –

          Parameter names can include the following letters and symbols.


        • Version (integer) –

          The parameter version.

        • Labels (list) –

          Labels assigned to the parameter version.

          • (string) –

        • Tier (string) –

          The parameter tier.

        • Policies (list) –

          Information about the policies assigned to a parameter.

          Assigning parameter policies in the Amazon Web Services Systems Manager User Guide.

          • (dict) –

            One or more policies assigned to a parameter.

            • PolicyText (string) –

              The JSON text of the policy.

            • PolicyType (string) –

              The type of policy. Parameter Store, a capability of Amazon Web Services Systems Manager, supports the following policy types: Expiration, ExpirationNotification, and NoChangeNotification.

            • PolicyStatus (string) –

              The status of the policy. Policies report the following statuses: Pending (the policy hasn’t been enforced or applied yet), Finished (the policy was applied), Failed (the policy wasn’t applied), or InProgress (the policy is being applied now).

        • DataType (string) –

          The data type of the parameter, such as text or aws:ec2:image. The default is text.

    • NextToken (string) –

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


  • SSM.Client.exceptions.InternalServerError

  • SSM.Client.exceptions.ParameterNotFound

  • SSM.Client.exceptions.InvalidNextToken

  • SSM.Client.exceptions.InvalidKeyId