class EvaluatorConfig 🔹

Language	Type name
.NET	Amazon.CDK.AWS.Bedrock.Agentcore.Alpha.EvaluatorConfig
Go	github.com/aws/aws-cdk-go/awsbedrockagentcorealpha/v2#EvaluatorConfig
Java	software.amazon.awscdk.services.bedrock.agentcore.alpha.EvaluatorConfig
Python	aws_cdk.aws_bedrock_agentcore_alpha.EvaluatorConfig
TypeScript (source)	@aws-cdk/aws-bedrock-agentcore-alpha » EvaluatorConfig

Configuration for a custom evaluator.

Defines how an evaluator assesses agent performance. Supports two strategies:

• LLM-as-a-Judge: Uses a foundation model with custom instructions and a rating scale.
• Code-based: Uses a Lambda function for custom evaluation logic.

Example

// LLM-as-a-Judge evaluator
const llmConfig = agentcore.EvaluatorConfig.llmAsAJudge({
  instructions: 'Evaluate whether the agent response is helpful.',
  modelId: 'us.anthropic.claude-sonnet-4-6',
  ratingScale: agentcore.EvaluatorRatingScale.categorical([
    { label: 'Good', definition: 'The response is helpful.' },
    { label: 'Bad', definition: 'The response is not helpful.' },
  ]),
});

// Code-based evaluator
declare const myEvalFunction: lambda.IFunction;
const codeConfig = agentcore.EvaluatorConfig.codeBased({
  lambdaFunction: myEvalFunction,
});

Properties

Name	Type	Description
lambdaFunction?🔹	IFunction	The Lambda function used for code-based evaluation, if applicable.

---

lambdaFunction?🔹

Type: IFunction (optional)

The Lambda function used for code-based evaluation, if applicable.

Methods

Name	Description
static codeBased(options)🔹	Creates a code-based evaluator configuration using a Lambda function.
static llmAsAJudge(options)🔹	Creates an LLM-as-a-Judge evaluator configuration.

---

static codeBased(options)🔹

public static codeBased(options: CodeBasedOptions): EvaluatorConfig

Parameters

• options CodeBasedOptions — - The code-based configuration options.

Returns

• EvaluatorConfig

Creates a code-based evaluator configuration using a Lambda function.

The Lambda function implements custom evaluation logic. The function will automatically be granted invoke permissions for the bedrock-agentcore service.

---

static llmAsAJudge(options)🔹

public static llmAsAJudge(options: LlmAsAJudgeOptions): EvaluatorConfig

Parameters

• options LlmAsAJudgeOptions — - The LLM-as-a-Judge configuration options.

Returns

• EvaluatorConfig

Creates an LLM-as-a-Judge evaluator configuration.

Uses a foundation model to assess agent performance based on custom instructions and a rating scale.