Anthropic exposes Claude Fable 5.1 through model ID claude-fable-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-fable-5-1— see the documentation for request format. - 3
Code Examples
pip install anthropicANTHROPIC_API_KEYclaude-fable-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-fable-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 Fable 5.1
Anthropic's generally available Mythos-class model for demanding reasoning, long-horizon agents, and ambitious coding, released September 1, 2026. Same underlying model as Claude Mythos 5.1 with cybersecurity and biology safeguards (flagged queries route to Opus 4.8 for cyber and Opus 5 for biology; those reroutes are not billed at Fable prices). Claude API id claude-fable-5-1. List price $10 per 1M input tokens and $50 per 1M output tokens; cache reads $0.25 per 1M (0.025x base input, 75% less than Fable 5's $1.00).