Anthropic exposes Claude Mythos 5.1 through model ID 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
- 2Use the Anthropic SDK or REST API to call
claude-mythos-5-1— see the documentation for request format. - 3
Code Examples
pip install anthropicANTHROPIC_API_KEYclaude-mythos-5-1Use the versioned model ID, e.g. "claude-sonnet-4-6" or "claude-opus-4-7-20251101".
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)Pricing on Anthropic
| Type | Price (per 1M) |
|---|---|
| Input tokens | $10.00 |
| Output tokens | $50.00 |
Capabilities
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.