lambda_function.py

import json, boto3

bedrock_agent = boto3.client(
    'bedrock-agent-runtime',
    region_name='us-east-1'
)

def lambda_handler(event, context):
    question = json.loads(event['body'])['question']

    response = bedrock_agent.retrieve_and_generate(
        input={'text': question},
        retrieveAndGenerateConfiguration={
            'type': 'KNOWLEDGE_BASE',
            'knowledgeBaseConfiguration': {
                'knowledgeBaseId': 'YOUR_KB_ID',
                'modelArn': 'arn:aws:bedrock:...:anthropic.claude-3-5-sonnet...'
    }})
    return {'statusCode': 200,
            'body': json.dumps({'answer': response['output']['text']})}