By using Claude Fable 5, you consent to data retention for purposes of monitoring safe and compliant use of AI. Anthropic's data retention policy does not allow zero data retention. Learn more(opens in new tab)
Azure, Google Vertex, and Amazon Bedrock endpoints are BYOK-only while we work on enabling public access.
Claude Fable 5 is a Mythos-class model from Anthropic, built for autonomous knowledge work and coding. It supports text, image, and file inputs with text output, with reasoning support and a 1M-token context window. It is suited for long-running, complex, and asynchronous tasks that previously required frequent human check-ins.
It is particularly strong at end-to-end work that would otherwise take a person hours, days, or weeks - taking on problems that are long-running, ambiguous, or highly multi-step. It executes well-scoped tasks with few mistakes, automatically self-correcting through verification loops, and ships with robust safeguards.
Modalities
In / Out Price
$10 / $50per 1M
Context
1M
Released
Jun 9, 2026
Claude Fable 5 is a Mythos-class model from Anthropic, built for autonomous knowledge work and coding. It supports text, image, and file inputs with text output, with reasoning support and a 1M-token context window. It is suited for long-running, complex, and asynchronous tasks that previously required frequent human check-ins.
Claude Fable 5 costs $10.00/M input tokens and $50.00/M output tokens, with separate rates for Cache Read at $1.00/M tokens, Cache Write at $12.50/M tokens, Cache Write (1h) at $20.00/M tokens and Web Search at $10.00/1K calls.
Claude Fable 5 has a 1,000,000 token context window. It supports up to 128,000 completion tokens.
Yes. Claude Fable 5 accepts tools and tool_choice for function calling. It also supports structured outputs via a JSON schema in response_format.
Claude Fable 5 accepts text, images and files such as PDFs as input and returns text.
Claude Fable 5 is served by 5 providers on OpenRouter: Claude Platform on AWS, Amazon Bedrock, Azure (BYOK Only), Anthropic and Google Vertex (Europe). Requests are routed to the best available provider, with automatic failover to the others, and you can pin or exclude providers with provider routing.
Claude Fable 5 was released on June 9, 2026.