# AlarmStateChangeDetail
<a name="API_AlarmStateChangeDetail"></a>

Details about a CloudWatch alarm state change observed during a test run.

## Contents
<a name="API_AlarmStateChangeDetail_Contents"></a>

 ** state **   <a name="ngresiliencehub-Type-AlarmStateChangeDetail-state"></a>
The state the alarm transitioned to.  
Type: String  
Valid Values: `OK | ALARM | INSUFFICIENT_DATA`   
Required: Yes

 ** previousState **   <a name="ngresiliencehub-Type-AlarmStateChangeDetail-previousState"></a>
The state the alarm transitioned from. Absent on the initial event, which records the alarm's state when collection began.  
Type: String  
Valid Values: `OK | ALARM | INSUFFICIENT_DATA`   
Required: No

 ** reason **   <a name="ngresiliencehub-Type-AlarmStateChangeDetail-reason"></a>
A human-readable explanation of the state change, as reported by CloudWatch.  
Type: String  
Length Constraints: Minimum length of 0. Maximum length of 1023.  
Required: No

## See Also
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For more information about using this API in one of the language-specific AWS SDKs, see the following:
+  [AWS SDK for C\+\+](https://docs.aws.amazon.com/goto/SdkForCpp/resiliencehubv2-2026-02-17/AlarmStateChangeDetail) 
+  [AWS SDK for Java V2](https://docs.aws.amazon.com/goto/SdkForJavaV2/resiliencehubv2-2026-02-17/AlarmStateChangeDetail) 
+  [AWS SDK for Ruby V3](https://docs.aws.amazon.com/goto/SdkForRubyV3/resiliencehubv2-2026-02-17/AlarmStateChangeDetail)