# HarnessHookEvent
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A lifecycle hook event emitted in the invocation stream for visibility into hook decisions.

## Contents
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 ** hookEventId **   <a name="BedrockAgentCore-Type-HarnessHookEvent-hookEventId"></a>
The unique identifier for this hook event.  
Type: String  
Pattern: `[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}`   
Required: Yes

 ** name **   <a name="BedrockAgentCore-Type-HarnessHookEvent-name"></a>
The name of the hook that ran.  
Type: String  
Length Constraints: Minimum length of 1. Maximum length of 64.  
Pattern: `[a-zA-Z0-9_-]+`   
Required: Yes

 ** type **   <a name="BedrockAgentCore-Type-HarnessHookEvent-type"></a>
The type of lifecycle hook event.  
Type: String  
Valid Values: `before_tool_call | after_tool_call | before_invocation | after_invocation`   
Required: Yes

 ** decision **   <a name="BedrockAgentCore-Type-HarnessHookEvent-decision"></a>
The decision applied to the hook event. This field is present only for blocking Lambda targets.  
Type: String  
Valid Values: `allow | deny`   
Required: No

 ** reason **   <a name="BedrockAgentCore-Type-HarnessHookEvent-reason"></a>
The optional reason for the applied decision.  
Type: String  
Length Constraints: Minimum length of 0. Maximum length of 1024.  
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/bedrock-agentcore-2024-02-28/HarnessHookEvent) 
+  [AWS SDK for Java V2](https://docs.aws.amazon.com/goto/SdkForJavaV2/bedrock-agentcore-2024-02-28/HarnessHookEvent) 
+  [AWS SDK for Ruby V3](https://docs.aws.amazon.com/goto/SdkForRubyV3/bedrock-agentcore-2024-02-28/HarnessHookEvent)