LLM Reference
Anthropic

Using Claude Fable 5 on Anthropic

Implementation guide · Claude Fable · Anthropic

Serverless

Anthropic exposes Claude Fable 5 through model ID claude-fable-5. Use the setup steps, sourced pricing, capabilities, and official provider links below to validate this route before deployment.

Last refreshed 2026-07-26. Next refresh: weekly.

Quick Start

  1. 1
    Create an account at Anthropic and generate an API key.
  2. 2
    Use the Anthropic SDK or REST API to call claude-fable-5 — see the documentation for request format.
  3. 3
    You'll be billed $10.00/1M input, $50.00/1M output tokens. See full pricing.

Code Examples

Install
pip install anthropic
API key
ANTHROPIC_API_KEY
Model ID
claude-fable-5

Use 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",
    max_tokens=1024,
    messages=[{"role": "user", "content": "Hello"}]
)
print(message.content[0].text)

Pricing on Anthropic

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

Capabilities

VisionMultimodalReasoningJSON / Tool useStructured OutputsPrompt CachingBatch API

About Claude Fable 5

Anthropic's most capable widely released model, built for demanding reasoning and long-horizon agentic work. Claude Fable 5 is the generally available Mythos-class Claude model, supports vision, tool use, structured outputs, prompt caching, Batch API processing, adaptive thinking that is always on, a 1M-token context window, and up to 128k output tokens. It launched on the Claude API, AWS Bedrock, Vertex AI, and Microsoft Foundry on June 9, 2026 with first-party pricing at $10 per 1M input tokens and $50 per 1M output tokens.

Model Specs

Released2026-06-09
Context1m
ArchitectureDecoder Only

Provider

Anthropic
Anthropic

San Francisco, California, United States