Claude Fable 5.1

Overview

The latest Mythos-class model for demanding reasoning and long-horizon agentic work, with always-on adaptive thinking and cache reads at a quarter of Fable 5's price. It is billed from the same balance as every other model and tool here, and the price of each call comes back in the response.

Run Claude Fable 5.1 with an agent

Each guide pairs this model with a currently compatible agent, explains their separate roles, and opens the shared Composer with both selections ready.

• Hermes + Claude Fable 5.1

  Compatibility, setup, current model facts, pricing boundaries, and a preselected Composer.

  Open guide

• Claude Code + Claude Fable 5.1

  Compatibility, setup, current model facts, pricing boundaries, and a preselected Composer.

  Open guide

• Codex + Claude Fable 5.1

  Compatibility, setup, current model facts, pricing boundaries, and a preselected Composer.

  Open guide

• OpenClaw + Claude Fable 5.1

  Compatibility, setup, current model facts, pricing boundaries, and a preselected Composer.

  Open guide

• pi + Claude Fable 5.1

  Compatibility, setup, current model facts, pricing boundaries, and a preselected Composer.

  Open guide

• DeepSeek Harness + Claude Fable 5.1

  Compatibility, setup, current model facts, pricing boundaries, and a preselected Composer.

  Open guide

• Kimi Code + Claude Fable 5.1

  Compatibility, setup, current model facts, pricing boundaries, and a preselected Composer.

  Open guide

• OpenCode + Claude Fable 5.1

  Compatibility, setup, current model facts, pricing boundaries, and a preselected Composer.

  Open guide

• DeepAgents + Claude Fable 5.1

  Compatibility, setup, current model facts, pricing boundaries, and a preselected Composer.

  Open guide

• goose + Claude Fable 5.1

  Compatibility, setup, current model facts, pricing boundaries, and a preselected Composer.

  Open guide

• Kilo + Claude Fable 5.1

  Compatibility, setup, current model facts, pricing boundaries, and a preselected Composer.

  Open guide

• MiniMax Code + Claude Fable 5.1

  Compatibility, setup, current model facts, pricing boundaries, and a preselected Composer.

  Open guide

• OpenHands + Claude Fable 5.1

  Compatibility, setup, current model facts, pricing boundaries, and a preselected Composer.

  Open guide

Prices in USD per million tokens, using your plan when signed in.

Your balance and per-call records come from /v1/credits and /v1/generation.

Use it

Point your client at the gateway and pass this model id. Nothing else changes.

import Anthropic from "@anthropic-ai/sdk";

const client = new Anthropic({
  baseURL: "https://gateway.agentsky.dev",
  apiKey: process.env.AGENTSKY_API_KEY, // ast_…
});

const message = await client.messages.create({
  model: "anthropic/claude-fable-5-1",
  max_tokens: 256,
  messages: [{ role: "user", content: "Summarise this ticket." }],
});
console.log(message.usage.cost); // USD, in the response

Questions

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