LLM Reference
Anthropic

Claude Mythos 5.1 on Anthropic

Claude Mythos · Anthropic

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

Why use Claude Mythos 5.1 on Anthropic?

Anthropic offers Claude Mythos 5.1 with pay-as-you-go pricing at $10.00/1M input tokens. Anthropic is a safety-focused AI research company and creator of the Claude model family, offering API access through the Anthropic Console for text generation, analysis, and coding tasks.

Compare Claude Mythos 5.1 across 4 providers to find the best fit for your use case
Input / 1M
$10.00
Output / 1M
$50.00
Cache
read $0.25 / 5m $12.50 / 1h $20.00
Batch
-50% · in $5.00 / out $25.00

Setup recipe

Python + curl
Install
pip install anthropic
Auth
export ANTHROPIC_API_KEY=...
Call
import anthropic
client = anthropic.Anthropic()  # reads ANTHROPIC_API_KEY from env
message = client.messages.create(
    model="claude-mythos-5-1",
Model ID
claude-mythos-5-1

Request example

import anthropic

client = anthropic.Anthropic()  # reads ANTHROPIC_API_KEY from env
message = client.messages.create(
    model="claude-mythos-5-1",
    max_tokens=1024,
    messages=[{"role": "user", "content": "Hello"}]
)
print(message.content[0].text)

Gotchas

  • Use the versioned model ID, e.g. "claude-sonnet-4-6" or "claude-opus-4-7-20251101".
  • The examples expect ANTHROPIC_API_KEY; rename it only if your application config maps the new variable.

Compare Claude Mythos 5.1 Across Providers

ProviderInput (per 1M)Output (per 1M)
Anthropic$10.00$50.00
AWS Bedrock
GCP Vertex AI
Microsoft Foundry$10.00$50.00

Pricing

TypePrice (per 1M)
Input tokens$10.00
Output tokens$50.00

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.

Get Started

Model Specs

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

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