Anthropic

Claude Fable 5 (batch)

by Anthropictext+image+file->text1 endpoint

Overview

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.

Capabilities

Text generation
Image understanding
Tool use / Function calling
Structured output
Extended reasoning
Prompt caching
Long context
File input
Stop sequences

Modalities

Input
TextImageFile
Output
Text

Technical Specifications

Context Window
1M tokens
Max Output
128K tokens
Tokenizer
Claude
Content Moderation
Enabled

Supported Parameters

include_reasoningmax_tokensreasoningreasoning_effortresponse_formatstopstructured_outputstool_choicetoolsverbosity

Pricing

Per 1M tokens
Input$5.00
Output$25.00
Cache read$0.50
Cache write$6.25
Added
June 9, 2026
Last synced 9/21/2026