# DescribeAlarms
Retrieves the specified alarms. You can filter the results by specifying a prefix for the alarm name, the alarm state, or a prefix for any action.
To use this operation and return information about composite alarms, you must be signed on with the `cloudwatch:DescribeAlarms` permission that is scoped to `*`. You can't return information about composite alarms if your `cloudwatch:DescribeAlarms` permission has a narrower scope.
## Request Parameters
** ActionPrefix **
Use this parameter to filter the results of the operation to only those alarms that use a certain alarm action. For example, you could specify the ARN of an SNS topic to find all alarms that send notifications to that topic.
Type: String
Length Constraints: Minimum length of 1. Maximum length of 1024.
Required: No
** AlarmNamePrefix **
An alarm name prefix. If you specify this parameter, you receive information about all alarms that have names that start with this prefix.
If this parameter is specified, you cannot specify `AlarmNames`.
Type: String
Length Constraints: Minimum length of 1. Maximum length of 255.
Required: No
** AlarmNames **
The names of the alarms to retrieve information about.
Type: Array of strings
Array Members: Maximum number of 100 items.
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, even if composite alarms exist in the account.
For example, if you omit this parameter or specify `MetricAlarms`, the operation returns only a list of metric alarms. It does not return any composite alarms, even if composite alarms exist in the account.
If you specify `CompositeAlarms`, the operation returns only a list of composite alarms, and does not return any metric alarms.
Type: Array of strings
Valid Values: `CompositeAlarm | MetricAlarm`
Required: No
** ChildrenOfAlarmName **
If you use this parameter and specify the name of a composite alarm, the operation returns information about the "children" alarms of the alarm you specify. These are the metric alarms and composite alarms referenced in the `AlarmRule` field of the composite alarm that you specify in `ChildrenOfAlarmName`. Information about the composite alarm that you name in `ChildrenOfAlarmName` is not returned.
If you specify `ChildrenOfAlarmName`, you cannot specify any other parameters in the request except for `MaxRecords` and `NextToken`. If you do so, you receive a validation error.
Only the `Alarm Name`, `ARN`, `StateValue` (OK/ALARM/INSUFFICIENT\$1DATA), and `StateUpdatedTimestamp` information are returned by this operation when you use this parameter. To get complete information about these alarms, perform another `DescribeAlarms` operation and specify the parent alarm names in the `AlarmNames` parameter.
Type: String
Length Constraints: Minimum length of 1. Maximum length of 255.
Required: No
** MaxRecords **
The maximum number of alarm descriptions 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
** ParentsOfAlarmName **
If you use this parameter and specify the name of a metric or composite alarm, the operation returns information about the "parent" alarms of the alarm you specify. These are the composite alarms that have `AlarmRule` parameters that reference the alarm named in `ParentsOfAlarmName`. Information about the alarm that you specify in `ParentsOfAlarmName` is not returned.
If you specify `ParentsOfAlarmName`, you cannot specify any other parameters in the request except for `MaxRecords` and `NextToken`. If you do so, you receive a validation error.
Only the Alarm Name and ARN are returned by this operation when you use this parameter. To get complete information about these alarms, perform another `DescribeAlarms` operation and specify the parent alarm names in the `AlarmNames` parameter.
Type: String
Length Constraints: Minimum length of 1. Maximum length of 255.
Required: No
** StateValue **
Specify this parameter to receive information only about alarms that are currently in the state that you specify.
Type: String
Valid Values: `OK | ALARM | INSUFFICIENT_DATA`
Required: No
## Response Elements
The following elements are returned by the service.
** CompositeAlarms **
The information about any composite alarms returned by the operation.
Type: Array of [CompositeAlarm](API_CompositeAlarm.md) objects
** MetricAlarms **
The information about any metric alarms returned by the operation.
Type: Array of [MetricAlarm](API_MetricAlarm.md) objects
** NextToken **
The token that marks the start of the next batch of returned results.
Type: String
## Errors
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
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/DescribeAlarms)
+ [AWS SDK for .NET V4](https://docs.aws.amazon.com/goto/DotNetSDKV4/monitoring-2010-08-01/DescribeAlarms)
+ [AWS SDK for C\$1\$1](https://docs.aws.amazon.com/goto/SdkForCpp/monitoring-2010-08-01/DescribeAlarms)
+ [AWS SDK for Go v2](https://docs.aws.amazon.com/goto/SdkForGoV2/monitoring-2010-08-01/DescribeAlarms)
+ [AWS SDK for Java V2](https://docs.aws.amazon.com/goto/SdkForJavaV2/monitoring-2010-08-01/DescribeAlarms)
+ [AWS SDK for JavaScript V3](https://docs.aws.amazon.com/goto/SdkForJavaScriptV3/monitoring-2010-08-01/DescribeAlarms)
+ [AWS SDK for Kotlin](https://docs.aws.amazon.com/goto/SdkForKotlin/monitoring-2010-08-01/DescribeAlarms)
+ [AWS SDK for PHP V3](https://docs.aws.amazon.com/goto/SdkForPHPV3/monitoring-2010-08-01/DescribeAlarms)
+ [AWS SDK for Python](https://docs.aws.amazon.com/goto/boto3/monitoring-2010-08-01/DescribeAlarms)
+ [AWS SDK for Ruby V3](https://docs.aws.amazon.com/goto/SdkForRubyV3/monitoring-2010-08-01/DescribeAlarms)