---
title: Claude Fable 5.1
url: https://platform.claude.com/docs/pt-BR/models/fable-5-1/overview
description: "Claude Fable 5.1 em resumo: para que serve, IDs do modelo em todas as plataformas, janela de contexto, limites de saída, preços, disponibilidade e recursos para construir com ele."
---
**Latest.** Released September 1, 2026.
For demanding reasoning and long-horizon agentic work
Model ID: `claude-fable-5-1`
Context window: 1M tokens · Max output: 128K tokens · Input pricing: $10 / MTok · Output pricing: $50 / MTok
[Announcement](https://www.anthropic.com/claude-fable-and-mythos-5-1) · [What’s new](https://platform.claude.com/docs/pt-BR/models/fable-5-1/whats-new-fable-5-1) · [Migration guide](https://platform.claude.com/docs/pt-BR/models/fable-5-1/migration-guide)
## Visão geral
O Claude Fable 5.1 estende o Claude Fable 5 com os mesmos preços de entrada e saída, com leituras de cache a um quarto do custo, e traz melhor desempenho em codificação agêntica de longa duração, pesquisa em várias etapas e trabalho com documentos, planilhas e slides. Para a maioria das cargas de trabalho, comece com o Claude Opus 5.5 (consulte [Escolhendo um modelo](https://platform.claude.com/docs/pt-BR/about-claude/models/choosing-a-model)). Use o Claude Fable 5.1 para raciocínio exigente e trabalho agêntico de longo horizonte, ou quando suas avaliações no Claude Opus 5.5 com esforço mais alto ainda ficarem aquém. O Claude Mythos 5.1 oferece as mesmas capacidades apenas para organizações verificadas por meio dos programas de verificação da Anthropic, como o [Cyber Verification Program](https://support.claude.com/en/articles/14604842).
Se você já chama o Claude Fable 5, três mudanças são incompatíveis: [o uso forçado de ferramentas retorna um erro](https://platform.claude.com/docs/pt-BR/models/fable-5-1/whats-new-fable-5-1#forced-tool-use-is-not-supported), [apenas o Claude Fable 5.1 e o Claude Mythos 5.1 podem ler os blocos de pensamento do Claude Fable 5.1](https://platform.claude.com/docs/pt-BR/models/fable-5-1/whats-new-fable-5-1#thinking-blocks-are-tied-to-the-model-that-produced-them) e [editar turnos anteriores invalida blocos de pensamento](https://platform.claude.com/docs/pt-BR/models/fable-5-1/whats-new-fable-5-1#editing-earlier-turns-invalidates-thinking-blocks). Cinco são aditivas: [esforço por mensagem](https://platform.claude.com/docs/pt-BR/models/fable-5-1/whats-new-fable-5-1#change-effort-mid-conversation-beta) (beta), [mensagens do sistema com escopo de turno](https://platform.claude.com/docs/pt-BR/models/fable-5-1/whats-new-fable-5-1#turn-scoped-system-messages-beta) (beta), [atualizações de progresso legíveis entre chamadas de ferramentas](https://platform.claude.com/docs/pt-BR/models/fable-5-1/whats-new-fable-5-1#progress-updates-between-tool-calls-beta) (`display: "updates"`, beta), um [preço menor de leitura de cache](https://platform.claude.com/docs/pt-BR/models/fable-5-1/whats-new-fable-5-1#pricing) e [proveniência de conteúdo](https://platform.claude.com/docs/pt-BR/models/fable-5-1/whats-new-fable-5-1#content-provenance).
[O que há de novo no Claude Fable 5.1](https://platform.claude.com/docs/pt-BR/models/fable-5-1/whats-new-fable-5-1)
## Claude Fable 5.1 e Claude Mythos 5.1
O [Claude Mythos 5.1](https://platform.claude.com/docs/pt-BR/models/mythos-5-1/overview) oferece as mesmas capacidades apenas para organizações verificadas por meio dos programas de verificação da Anthropic, como o [Cyber Verification Program](https://support.claude.com/en/articles/14604842). Ele compartilha as especificações e os preços do Claude Fable 5.1. Para solicitar acesso, inscreva-se no programa que abrange o seu caso de uso ou entre em contato com a sua equipe de conta da Anthropic, AWS ou Google Cloud.
## Como ele se compara
| Model | Context | Max output | Price / MTok | Latency | Thinking | Default effort | Knowledge cutoff |
| :------------------------------------------------------------------------------------- | :------ | :--------- | :----------------- | :------- | :------------------- | :------------- | :--------------- |
| **Claude Fable 5.1** (this model) | 1M | 128K | $10 / $50 | Slower | Adaptive (always on) | `high` | Jun 2026 |
| [Claude Opus 5.5](https://platform.claude.com/docs/pt-BR/models/opus-5-5/overview) | 1M | 128K | $4 / $20 | Moderate | Adaptive (always on) | `medium` | Jun 2026 |
| [Claude Sonnet 5.5](https://platform.claude.com/docs/pt-BR/models/sonnet-5-5/overview) | 1M | 128K | $2 / $10 | Fast | Adaptive | `high` | Jun 2026 |
| [Claude Haiku 5.5](https://platform.claude.com/docs/pt-BR/models/haiku-5-5/overview) | 1M | 128K | From $0.10 / $0.50 | Fastest | Adaptive | `medium` | Jun 2026 |
* **Context:** 1M tokens is roughly 555k words or 2.5M Unicode characters on the current tokenizer (introduced with Claude Opus 4.7); models before it fit about 750k words in 1M tokens. 200k tokens is roughly 150k words.
* **Max output:** Synchronous Messages API limit. On the Message Batches API, Claude Opus 5.5, Claude Opus 5, Claude Sonnet 5.5, Claude Sonnet 5, Claude Haiku 5.5, Claude Opus 4.8, Claude Opus 4.7, Claude Opus 4.6, and Claude Sonnet 4.6 support up to 300k output tokens with the output-300k-2026-03-24 beta header.
* **Price / MTok:** Input / output, base price per million tokens. Batch API requests are 50% off; prompt caching reads cost 10% of the base input price (2.5% on Claude Fable 5.1 and Claude Mythos 5.1, 5% on Claude Opus 5.5 and Claude Sonnet 5.5). See Pricing for the full list.
* **Latency:** Comparative latency, relative to the current lineup, as published in the models overview. Actual latency depends on prompt length, output length, and thinking effort.
* **Thinking:** Adaptive thinking lets the model decide how much to think, steered by effort. Extended thinking is the manual budget\_tokens mode on earlier models.
* **Default effort:** The effort parameter’s default on the Claude API. Models without a value don’t support the parameter.
* **Knowledge cutoff:** Reliable knowledge cutoff: the date through which the model’s knowledge is most extensive and reliable.
## Especificações
### Model IDs
| Platform | Model ID |
| :-------------------------------------------------------------------------------------------------------- | :--------------------------- |
| Claude API | `claude-fable-5-1` |
| [Amazon Bedrock](https://platform.claude.com/docs/pt-BR/build-with-claude/claude-in-amazon-bedrock) | `anthropic.claude-fable-5-1` |
| [Google Cloud](https://platform.claude.com/docs/pt-BR/build-with-claude/claude-on-vertex-ai) | `claude-fable-5-1` |
| [Microsoft Foundry](https://platform.claude.com/docs/pt-BR/build-with-claude/claude-in-microsoft-foundry) | `claude-fable-5-1` |
| [Claude Platform on AWS](https://platform.claude.com/docs/pt-BR/build-with-claude/claude-platform-on-aws) | `claude-fable-5-1` |
### Pricing
| Feature | Value |
| :---------------------------------------------------------------------------------------- | :------------------------------- |
| Input | $10 / MTok |
| Output | $50 / MTok |
| [5m cache write](https://platform.claude.com/docs/pt-BR/build-with-claude/prompt-caching) | $12.50 / MTok |
| [1h cache write](https://platform.claude.com/docs/pt-BR/build-with-claude/prompt-caching) | $20 / MTok |
| [Cache read](https://platform.claude.com/docs/pt-BR/build-with-claude/prompt-caching) | $0.25 / MTok |
| [Batch API](https://platform.claude.com/docs/pt-BR/build-with-claude/batch-processing) | 50% discount on input and output |
[Full price list](https://platform.claude.com/docs/pt-BR/about-claude/pricing)
### Capabilities
| Feature | Value |
| :----------------------------------------------------------------------------------------- | :--------------------- |
| [Context window](https://platform.claude.com/docs/pt-BR/build-with-claude/context-windows) | 1M tokens |
| Max output | 128K tokens |
| [Thinking](https://platform.claude.com/docs/pt-BR/build-with-claude/thinking) | Adaptive (always on) |
| [Default effort](https://platform.claude.com/docs/pt-BR/build-with-claude/effort) | `high` |
| Comparative latency | Slower |
| Input → output | Text and images → text |
| Reliable knowledge cutoff | Jun 2026 |
| Training data cutoff | Jun 2026 |
### Availability
| Feature | Value |
| :------------------------------------------------------------------------------- | :---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| [Status](https://platform.claude.com/docs/pt-BR/about-claude/model-deprecations) | Active (latest) |
| Released | September 1, 2026 |
| Retirement | Not sooner than September 1, 2027 |
| Platforms | Claude API, [Amazon Bedrock](https://platform.claude.com/docs/pt-BR/build-with-claude/claude-in-amazon-bedrock), [Google Cloud](https://platform.claude.com/docs/pt-BR/build-with-claude/claude-on-vertex-ai), [Microsoft Foundry](https://platform.claude.com/docs/pt-BR/build-with-claude/claude-in-microsoft-foundry), [Claude Platform on AWS](https://platform.claude.com/docs/pt-BR/build-with-claude/claude-platform-on-aws) |
## Recursos
Orientações de prompting específicas do modelo para trabalhos de longo horizonte e agênticos.
O que muda quando você migra do Claude Fable 5, Claude Opus 5 ou Claude Opus 4.8.
Quando os blocos de pensamento deste modelo continuam utilizáveis: entre trocas de modelo e entre alterações na conversa.
Altere o nível de esforço no meio de uma conversa sem invalidar o cache de prompt.
Lide com recusas do classificador e tente novamente em outro modelo Claude.
O único modo de pensamento no Claude Fable 5.1. Controle a profundidade com `effort`.
## Referência
O prompt do sistema que o Claude Fable 5.1 usa no claude.ai e nos aplicativos Claude.
Avaliações de segurança e decisões de implantação para o Claude Fable 5.1 e o Claude Mythos 5.1.
Lista completa de preços, incluindo descontos para lotes e tarifas de cache de prompt.
Como funcionam os IDs de modelo, aliases e snapshots fixados.
Status do ciclo de vida e compromissos de desativação para cada modelo Claude.