LLM Reference
AWS Bedrock

Using Claude Mythos 5.1 on AWS Bedrock

Implementation guide · Claude Mythos · Anthropic

Serverless

AWS Bedrock exposes Claude Mythos 5.1 through model ID anthropic.claude-mythos-5-1. Use the setup steps, sourced pricing, capabilities, and official provider links below to validate this route before deployment.

Last refreshed 2026-09-01. Next refresh: weekly.

Quick Start

  1. 1
    Create an account at AWS Bedrock and generate an API key.
  2. 2
    Use the AWS Bedrock SDK or REST API to call anthropic.claude-mythos-5-1 — see the documentation for request format.

Code Examples

Install
pip install boto3
API key
AWS_ACCESS_KEY_ID
Model ID
anthropic.claude-mythos-5-1

Use Amazon Bedrock model IDs, e.g. "anthropic.claude-3-opus-20240229-v1:0" for on-demand, or cross-region inference profile IDs like "us.anthropic.claude-opus-4-7-20251101-v1:0". These differ from the public model slug.

import boto3

# Reads AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY, AWS_DEFAULT_REGION from env
client = boto3.client("bedrock-runtime", region_name="us-east-1")
response = client.converse(
    modelId="anthropic.claude-mythos-5-1",
    messages=[{
        "role": "user",
        "content": [{"text": "Hello"}]
    }]
)
print(response["output"]["message"]["content"][0]["text"])

Pricing on AWS Bedrock

Capabilities

VisionMultimodalReasoningJSON / Tool useStructured OutputsCode ExecutionPrompt CachingBatch API

About Claude Mythos 5.1

Anthropic's invitation-only Mythos-class model, released September 1, 2026. Same underlying model as Claude Fable 5.1 without the cybersecurity and biology safeguards. Access is limited to a small set of vetted organizations through trusted access / Project Glasswing; Anthropic currently makes it available to a set of US organizations and is working to expand. Claude API id claude-mythos-5-1. Pricing starts at $10 per 1M input tokens and $50 per 1M output tokens (limited availability; no cheaper public tier published). Cache reads $0.25 per 1M. 1M-token context, 128K max output, adaptive thinking always on, text and image input to text output.

Model Specs

Released2026-09-01
Context1m
ArchitectureDecoder Only
Knowledge cutoff2026-06

Provider

AWS Bedrock
AWS Bedrock

Amazon Web Services

Seattle, Washington, United States