Accessing Amazon Bedrock Claude-3-Haiku and Claude-3-Sonnet models via Lambda Functions

Hello.

I'm not sure since I haven't seen the full code, but are you using the Text Completions API?
Amazon Bedrock's Text Completions API cannot use Claude-3-Sonnet etc. as of March 2024.
Only the following models are compatible.
https://docs.aws.amazon.com/bedrock/latest/userguide/model-parameters-anthropic-claude-text-completion.html

• Anthropic Claude Instant v1.2
• Anthropic Claude v2
• Anthropic Claude v2.1

For Messages API, you can use Claude-3-Sonnet etc. as shown below.
https://docs.aws.amazon.com/bedrock/latest/userguide/model-parameters-anthropic-claude-messages.html

import boto3
import json

def lambda_handler(event, context):

    bedrock = boto3.client('bedrock-runtime', region_name = "us-east-1")
    body = json.dumps(
        {
            "anthropic_version": "bedrock-2023-05-31",
            "max_tokens": 1000,
            "messages": [
                {
                    "role": "user",
                    "content": [
                        {
                            "type": "text",
                            "text":"Hello My name is Riku"
                        }
                    ]
                }
            ]
        }
    )
    modelId = 'anthropic.claude-3-sonnet-20240229-v1:0'
    accept = 'application/json'
    contentType = 'application/json'
    response = bedrock.invoke_model(body=body, modelId=modelId, accept=accept, contentType=contentType)
    response_body = json.loads(response.get('body').read())
    answer = response_body["content"][0]["text"]
    print(answer)