# DescribeAlarmHistory
<a name="API_DescribeAlarmHistory"></a>

Retrieves the history for the specified alarm. You can filter the results by date range or item type. If an alarm name is not specified, the histories for either all metric alarms or all composite alarms are returned.

CloudWatch retains the history of an alarm even if you delete the alarm.

To use this operation and return information about a composite alarm, you must be signed on with the `cloudwatch:DescribeAlarmHistory` permission that is scoped to `*`. You can't return information about composite alarms if your `cloudwatch:DescribeAlarmHistory` permission has a narrower scope.

## Request Parameters
<a name="API_DescribeAlarmHistory_RequestParameters"></a>

 ** AlarmContributorId **   
The unique identifier of a specific alarm contributor to filter the alarm history results.  
Type: String  
Length Constraints: Minimum length of 1. Maximum length of 16.  
Required: No

 ** AlarmName **   
The name of the alarm.  
Type: String  
Length Constraints: Minimum length of 1. Maximum length of 255.  
Required: No

 ** AlarmTypes **   
Use this parameter to specify whether you want the operation to return metric alarms or composite alarms. If you omit this parameter, only metric alarms are returned.  
Type: Array of strings  
Valid Values: `CompositeAlarm | MetricAlarm`   
Required: No

 ** EndDate **   
The ending date to retrieve alarm history.  
Type: Timestamp  
Required: No

 ** HistoryItemType **   
The type of alarm histories to retrieve.  
Type: String  
Valid Values: `ConfigurationUpdate | StateUpdate | Action | AlarmContributorStateUpdate | AlarmContributorAction`   
Required: No

 ** MaxRecords **   
The maximum number of alarm history records to retrieve.  
Type: Integer  
Valid Range: Minimum value of 1. Maximum value of 100.  
Required: No

 ** NextToken **   
The token returned by a previous call to indicate that there is more data available.  
Type: String  
Required: No

 ** ScanBy **   
Specified whether to return the newest or oldest alarm history first. Specify `TimestampDescending` to have the newest event history returned first, and specify `TimestampAscending` to have the oldest history returned first.  
Type: String  
Valid Values: `TimestampDescending | TimestampAscending`   
Required: No

 ** StartDate **   
The starting date to retrieve alarm history.  
Type: Timestamp  
Required: No

## Response Elements
<a name="API_DescribeAlarmHistory_ResponseElements"></a>

The following elements are returned by the service.

 ** AlarmHistoryItems **   
The alarm histories, in JSON format.  
Type: Array of [AlarmHistoryItem](API_AlarmHistoryItem.md) objects

 ** NextToken **   
The token that marks the start of the next batch of returned results.  
Type: String

## Errors
<a name="API_DescribeAlarmHistory_Errors"></a>

For information about the errors that are common to all actions, see [Common Error Types](CommonErrors.md).

 ** InvalidNextToken **   
The next token specified is invalid.    
 ** message **   

HTTP Status Code: 400

## See Also
<a name="API_DescribeAlarmHistory_SeeAlso"></a>

For more information about using this API in one of the language-specific AWS SDKs, see the following:
+  [AWS Command Line Interface V2](https://docs.aws.amazon.com/goto/cli2/monitoring-2010-08-01/DescribeAlarmHistory) 
+  [AWS SDK for .NET V4](https://docs.aws.amazon.com/goto/DotNetSDKV4/monitoring-2010-08-01/DescribeAlarmHistory) 
+  [AWS SDK for C\$1\$1](https://docs.aws.amazon.com/goto/SdkForCpp/monitoring-2010-08-01/DescribeAlarmHistory) 
+  [AWS SDK for Go v2](https://docs.aws.amazon.com/goto/SdkForGoV2/monitoring-2010-08-01/DescribeAlarmHistory) 
+  [AWS SDK for Java V2](https://docs.aws.amazon.com/goto/SdkForJavaV2/monitoring-2010-08-01/DescribeAlarmHistory) 
+  [AWS SDK for JavaScript V3](https://docs.aws.amazon.com/goto/SdkForJavaScriptV3/monitoring-2010-08-01/DescribeAlarmHistory) 
+  [AWS SDK for Kotlin](https://docs.aws.amazon.com/goto/SdkForKotlin/monitoring-2010-08-01/DescribeAlarmHistory) 
+  [AWS SDK for PHP V3](https://docs.aws.amazon.com/goto/SdkForPHPV3/monitoring-2010-08-01/DescribeAlarmHistory) 
+  [AWS SDK for Python](https://docs.aws.amazon.com/goto/boto3/monitoring-2010-08-01/DescribeAlarmHistory) 
+  [AWS SDK for Ruby V3](https://docs.aws.amazon.com/goto/SdkForRubyV3/monitoring-2010-08-01/DescribeAlarmHistory)