Claude Fable 5

Announcements: Claude Fable 5 and Claude Mythos 5 Jun 9, 2026 公告：Claude Fable 5 与 Claude Mythos 5 2026年6月9日

Today we’re launching Claude Fable 5: a Mythos-class model that we’ve made safe for general use. 今天，我们正式发布 Claude Fable 5：这是一款我们已确保可供通用使用的 Mythos 级模型。

Fable 5’s capabilities exceed those of any model we’ve ever made generally available. It is state-of-the-art on nearly all tested benchmarks of AI capability, showing exceptional performance in software engineering, knowledge work, vision, scientific research, and many other areas. The longer and more complex the task, the larger Fable 5’s lead over our other models. Fable 5 的能力超越了我们以往公开发布的任何模型。它在几乎所有经过测试的 AI 能力基准上均处于行业领先水平，在软件工程、知识工作、视觉处理、科学研究及其他诸多领域表现卓越。任务越长、越复杂，Fable 5 相较于我们其他模型的优势就越明显。

Releasing a model this capable comes with risks. Without safeguards, Fable 5’s capabilities in areas like cybersecurity could be misused to cause serious damage. We’ve therefore launched the model with safeguards that mean queries on some topics will instead receive a response from our next-most-capable model, Claude Opus 4.8. To release the model both safely and quickly, we’ve tuned these safeguards conservatively—they’ll sometimes catch harmless requests, though they trigger, on average, in less than 5% of sessions. With more capable models arriving in the coming months, we’re working to improve our safeguards and reduce false positives as quickly as we can. 发布如此强大的模型伴随着风险。如果没有安全防护，Fable 5 在网络安全等领域的能力可能会被滥用，从而造成严重损害。因此，我们在发布该模型时加入了安全机制，这意味着针对某些主题的查询将由我们能力次之的模型 Claude Opus 4.8 来回答。为了在安全和快速之间取得平衡，我们对这些防护措施进行了保守调整——它们有时会拦截无害的请求，尽管平均触发率不到 5%。随着未来几个月更强模型的推出，我们正致力于尽快改进防护措施并减少误报。

For a small group of cyberdefenders and infrastructure providers, we’re also launching Claude Mythos 5. It’s the same underlying model as Fable 5, but with the safeguards lifted in some areas. Mythos 5 will initially be deployed through Project Glasswing, in collaboration with the US government, as an upgrade to Claude Mythos Preview. It has the strongest cybersecurity capabilities of any model in the world. Soon, we intend to expand access to Mythos 5 through a broader trusted access program. 针对一小部分网络防御者和基础设施提供商，我们还推出了 Claude Mythos 5。它与 Fable 5 采用相同的底层模型，但在某些领域取消了安全限制。Mythos 5 最初将通过与美国政府合作的“Glasswing 项目”（Project Glasswing）进行部署，作为 Claude Mythos Preview 的升级版。它是目前全球网络安全能力最强的模型。我们计划在不久后通过更广泛的受信任访问计划，扩大 Mythos 5 的使用范围。

The capabilities of models like Fable 5 and Mythos 5 have the potential to do profound good for the world. We’ve seen the beginnings of this in Project Glasswing, where the models have helped cyber defenders secure critically important software. We’ve also seen it in life sciences research, where the models are positing novel hypotheses and speeding up the development of new therapeutics. 像 Fable 5 和 Mythos 5 这样的模型，其能力有望为世界带来深远的福祉。我们在 Glasswing 项目中已经看到了初步成果，这些模型帮助网络防御者保护了关键软件。在生命科学研究领域，我们也看到了它们的潜力，模型能够提出新颖的假设并加速新疗法的开发。

Fable 5 and Mythos 5 are being offered at $10 per million input tokens and $50 per million output tokens—less than half the price of Claude Mythos Preview. Today’s joint launch is another step towards our goal of bringing advanced AI capabilities to as many users as possible, as quickly and as safely as we can. Fable 5 和 Mythos 5 的定价为每百万输入 token 10 美元，每百万输出 token 50 美元——价格不到 Claude Mythos Preview 的一半。今天的联合发布是我们实现目标过程中的又一步，旨在尽可能快速、安全地将先进的 AI 能力带给尽可能多的用户。

Evaluating Claude Fable 5 and Claude Mythos 5 评估 Claude Fable 5 与 Claude Mythos 5

The table below compares the capabilities of Fable 5 and Mythos 5 to other leading models. Fable 5 and Mythos 5 can work autonomously for longer than any previous Claude models. Below we discuss how these skills apply to software engineering, and cover the model’s improved capabilities in knowledge work, vision, memory, and life sciences research. 下表对比了 Fable 5 和 Mythos 5 与其他领先模型的能力。Fable 5 和 Mythos 5 的自主工作时长超过了以往任何 Claude 模型。以下我们将探讨这些技能在软件工程中的应用，并涵盖模型在知识工作、视觉、记忆和生命科学研究方面能力的提升。

Software engineering. During early testing, Stripe reported that Fable 5 compressed months of engineering into days. In a 50-million-line Ruby codebase, the model performed a codebase-wide migration in a day that would otherwise have taken a whole team over two months by hand. Fable 5 is also more token-efficient than past Claude models: on Cognition’s FrontierCode evaluation, which tests whether models can pass difficult coding tasks while meeting the standards of high-quality production codebases, Fable 5 scores highest among frontier models, even at medium effort. 软件工程。 在早期测试中，Stripe 报告称 Fable 5 将数月的工程量压缩到了几天内完成。在一个拥有 5000 万行代码的 Ruby 代码库中，该模型在一天内完成了全库迁移，而这原本需要整个团队手动操作两个多月。Fable 5 在 token 使用上也比以往的 Claude 模型更高效：在 Cognition 的 FrontierCode 评估中（该评估测试模型在通过困难编码任务的同时是否符合高质量生产代码库的标准），Fable 5 在前沿模型中得分最高，即使是在中等努力程度下也是如此。

Knowledge work. Fable 5 shows strong performance on complex analytical tasks. On Hebbia’s Finance Benchmark for senior-level reasoning, Fable 5 has the highest score of any model, with substantial gains in document-based reasoning, chart and table interpretation, and problem solving. IMC noted that Fable 5 aced their trading-analysis evaluations nearly across the board, including factual lookup, conceptual reasoning, root-cause analysis, and expected-value analysis. 知识工作。 Fable 5 在复杂分析任务中表现强劲。在 Hebbia 的高级推理金融基准测试中，Fable 5 的得分位居所有模型之首，在基于文档的推理、图表解读和问题解决方面取得了显著进步。IMC 指出，Fable 5 在他们的交易分析评估中几乎全线通过，包括事实查询、概念推理、根本原因分析和期望值分析。

Vision. Fable 5 is the new state-of-the-art model for tasks involving vision. It can extract precise numbers from detailed scientific figures and can perform complex vision-based tasks like rebuilding a web app’s source code from screenshots alone. It also needs less scaffolding: for example, previous Claude models struggled to play Pokémon FireRed even with harnesses that gave them additional helpful tools, but Fable 5 beat FireRed with a minimal, vision-only harness. 视觉。 Fable 5 是目前视觉相关任务中最先进的模型。它能从详细的科学图表中提取精确数据，并能执行复杂的视觉任务，例如仅凭截图重建 Web 应用的源代码。它所需的辅助框架也更少：例如，以前的 Claude 模型即使在提供额外辅助工具的情况下，在玩《宝可梦：火红》时也表现吃力，但 Fable 5 仅凭最基础的视觉辅助就通关了《火红》。

A timelapse of Claude playing Pokémon FireRed from start to finish using only raw game screenshots — with no maps, navigation aids, or extra game-state information. Earlier Claude models needed a complex helper harness to play Pokémon; Claude Fable 5 completed the game with vision alone. Claude 仅使用原始游戏截图从头到尾通关《宝可梦：火红》的延时视频——过程中没有地图、导航辅助或额外的游戏状态信息。早期的 Claude 模型需要复杂的辅助框架才能玩宝可梦；而 Claude Fable 5 仅凭视觉就完成了游戏。

Memory and long-context. Fable 5 stays focused across millions of tokens in long-running tasks and improves its outputs using its own notes. When we had the model play the deck-building game Slay the Spire, giving it access to persistent file-based memory improved its performance three times more than for Opus 4.8; Fable also reached the game’s final act three times more often. 记忆与长上下文。 Fable 5 在长时间运行的任务中能跨越数百万 token 保持专注，并利用自己的笔记改进输出。当我们让模型玩卡牌构建游戏《杀戮尖塔》（Slay the Spire）时，为其提供持久化的文件记忆功能，使其性能提升幅度是 Opus 4.8 的三倍；Fable 到达游戏最终幕的频率也高出三倍。

Solar eclipses / Factorio / VibeCAD / Fluid with Classical EDM 日食 / 异星工厂 (Factorio) / VibeCAD / 伴随古典 EDM 的流体模拟

Claude Fable 5 built this simulation of the solar system, deriving the planets’ orbital motion from physics first principles and using it to predict solar eclipses. Claude Fable 5 构建了这个太阳系模拟，从物理学第一性原理推导出行星的轨道运动，并利用它来预测日食。

Claude Fable 5 autonomously plays Factorio, the factory-building game beloved by engineers, strategizing and building an automated factory on its own. Claude Fable 5 自主游玩工程师们喜爱的工厂建造游戏《异星工厂》，自行制定策略并建造自动化工厂。

Claude Fable 5 designs a complete 3D-printable model in a browser-based CAD editor. The editor itself was also created by Fable 5, including the built-in AI copilot that does the modeling. Claude Fable 5 在基于浏览器的 CAD 编辑器中设计了一个完整的 3D 打印模型。该编辑器本身也是由 Fable 5 创建的，包括负责建模的内置 AI 副驾驶。

A fluid simulation coded by Claude Fable 5 where the motion is synchronized to the beat of a classical music EDM remix — which Claude Fable 5 produced using code, having never heard music before. 由 Claude Fable 5 编写代码实现的流体模拟，其运动与古典音乐 EDM 混音的节拍同步——该音乐也是 Claude Fable 5 在从未听过音乐的情况下，通过代码创作出来的。

Drug design: Using Mythos 5, our internal protein design experts accelerated aspects of the drug design process by around ten times. In one example, they found that Mythos 5, with protein design and bioinformatics tools but no human assistance, matches or beats skilled human experts. 药物设计：利用 Mythos 5，我们的内部蛋白质设计专家将药物设计过程的某些环节加速了约十倍。在一个案例中，他们发现 Mythos 5 在配备蛋白质设计和生物信息学工具且无人协助的情况下，其表现与熟练的人类专家相当甚至更胜一筹。