Anthropic’s Claude Fable 5 is a version of Mythos the public can access today
Anthropic’s Claude Fable 5 is a version of Mythos the public can access today
Anthropic 的 Claude Fable 5 是公众今日即可使用的 Mythos 版本
Anthropic is bringing its most powerful AI model to the general public for the first time, but it’s doing it with guardrails. On Tuesday, the AI firm launched Claude Fable 5, the first publicly available version of its Mythos model. Anthropic says Fable 5 excels at software engineering, knowledge work, and vision, but it comes with hard safety limits. In high-risk areas like cybersecurity, biology, chemistry, and distillation, the model blocks responses and falls back to Claude Opus 4.8.
Anthropic 首次将其最强大的 AI 模型推向公众，但同时也设置了安全护栏。周二，这家 AI 公司发布了 Claude Fable 5，这是其 Mythos 模型首个公开版本。Anthropic 表示，Fable 5 在软件工程、知识工作和视觉处理方面表现出色，但它带有严格的安全限制。在网络安全、生物学、化学和蒸馏等高风险领域，该模型会拦截响应并自动切换回 Claude Opus 4.8。
Launched as a preview in April, Mythos was initially limited to a handful of partners due to cybersecurity concerns. Last week, Anthropic expanded access to hundreds of organizations across 15 countries, again focusing on organizations that manage critical infrastructure. Now a version of that technology is available to anyone through Anthropic’s Claude API and consumption-based Enterprise plans.
Mythos 于 4 月作为预览版推出，最初因网络安全顾虑仅限于少数合作伙伴使用。上周，Anthropic 将访问权限扩大到 15 个国家的数百个组织，重点依然是管理关键基础设施的机构。现在，该技术的一个版本已通过 Anthropic 的 Claude API 和基于消费的企业计划向所有人开放。
Access on subscriptions will roll out in stages: Through June 22, Fable 5 will be included in Pro, Max, Team, and seat-based Enterprise plans at no extra cost. On June 23, Anthropic will pull Fable 5 from those plans, requiring usage credits going forward, with plans to restore it as a standard subscription feature as soon as possible. Anthropic is also deploying a new version of Mythos, called Mythos 5, to organizations that have already been approved to access the advanced model.
订阅访问权限将分阶段推出：在 6 月 22 日之前，Fable 5 将免费包含在 Pro、Max、Team 和基于席位的企业计划中。6 月 23 日起，Anthropic 将从这些计划中移除 Fable 5，后续需使用额度（usage credits）进行调用，并计划尽快将其恢复为标准订阅功能。此外，Anthropic 正在向已获准访问该高级模型的组织部署名为 Mythos 5 的新版本。
Fable’s launch comes as Anthropic prepares to enter the public markets, alongside OpenAI and Elon Musk’s SpaceX. It also follows the AI firm’s plea urging major global AI labs to establish a coordinated brake pedal on frontier AI development. Anthropic warned that systems are advancing so rapidly that they may soon achieve recursive self-improvement (RSI), autonomously improving themselves without human intervention.
Fable 的发布正值 Anthropic 与 OpenAI 和埃隆·马斯克的 SpaceX 一起准备进入公开市场之际。此前，该公司还曾呼吁全球主要 AI 实验室为前沿 AI 开发建立协调的“刹车机制”。Anthropic 警告称，系统进步速度极快，可能很快就会实现递归自我改进（RSI），即在没有人类干预的情况下自主优化自身。
Wary of what a Mythos-class model could do in the wrong hands, Anthropic says it stress-tested its classifiers with jailbreak attempts before releasing Fable 5. “Internally, we ran an external bug bounty that produced no universal jailbreaks in over 1,000 hours of testing. We then worked with external red-teaming orgs which also failed to find universal jailbreaks.”
由于担心 Mythos 级别的模型落入不法之徒手中，Anthropic 表示在发布 Fable 5 之前，已通过越狱尝试对其分类器进行了压力测试。“在内部，我们进行了外部漏洞赏金计划，在超过 1,000 小时的测试中没有发现通用的越狱方法。随后，我们与外部红队组织合作，他们也未能找到通用的越狱手段。”
That said, there could still be novel attacks. As a result, with the launch of Fable 5 and Mythos 5, Anthropic said it will require a 30-day retention on all traffic, even if enterprises previously had zero-retention agreements. The company said it won’t use the data for training and will use it only to “defend against complex and novel attacks, including new jailbreaks,” and “identify and reduce false positives.” The policy could set an industry precedent in which access to increasingly powerful models comes with mandatory data-retention policies framed as a safety measure.
尽管如此，仍可能存在新型攻击。因此，随着 Fable 5 和 Mythos 5 的发布，Anthropic 表示将要求对所有流量进行 30 天的保留，即使企业此前签署了零保留协议。该公司表示，不会将这些数据用于训练，仅用于“防御复杂和新型攻击（包括新的越狱手段）”以及“识别和减少误报”。这项政策可能会开创行业先例，即访问日益强大的模型必须伴随以安全措施为名的强制性数据保留政策。
For those who continue to use the model, not every question will get a Fable 5 answer. Anthropic says the cases in which Fable has to defer to Opus 4.8 are rare, with early data showing at least 95% of Fable sessions running entirely on the model’s own responses. In third-party testing, analytics company Hex said in a statement that Fable was the first to get a 90% on its core analytics benchmark of complex, long-running analytical tasks. “On the hardest questions, it shows strong judgement and attention to nuance,” Hex said.
对于继续使用该模型的用户，并非每个问题都会得到 Fable 5 的回答。Anthropic 表示，Fable 需要转交给 Opus 4.8 处理的情况很少见，早期数据显示至少 95% 的 Fable 会话完全由模型自身响应。在第三方测试中，分析公司 Hex 在声明中表示，Fable 是首个在其针对复杂、长期分析任务的核心分析基准测试中获得 90 分的模型。“在最困难的问题上，它表现出了强大的判断力和对细微差别的关注，”Hex 评价道。
Vibe-coding platform Base44 noted in a statement that Fable is better at “one-shotting full apps” and has excellent tool-calling. AI-powered workspace and agent platform Genspark said Fable beat every other model in its evaluations and performed significantly better on tasks like UI design and game coding.
Vibe-coding 平台 Base44 在声明中指出，Fable 在“一次性生成完整应用”方面表现更好，并具备出色的工具调用能力。AI 工作空间和代理平台 Genspark 表示，Fable 在其评估中击败了所有其他模型，在 UI 设计和游戏编码等任务上的表现显著优于其他模型。
Pricing for both Fable 5 and Mythos 5 is $10 per million input tokens and $50 per million output tokens, double the price of Opus 4.8. That price alone might serve as a deterrent for widespread use. Many enterprises are growing critical of AI costs after seeing the bills come in or blowing through their yearly AI budgets early. Advanced models like Opus 4.8 can exacerbate those issues, with advanced reasoning skills that can split a single request into multiple tasks.
Fable 5 和 Mythos 5 的定价均为每百万输入 Token 10 美元，每百万输出 Token 50 美元，是 Opus 4.8 价格的两倍。仅此价格就可能成为广泛使用的阻碍。许多企业在看到账单或提前耗尽年度 AI 预算后，开始对 AI 成本持批评态度。像 Opus 4.8 这样的高级模型可能会加剧这些问题，因为它们具备将单个请求拆分为多个任务的高级推理能力。
Anthropic said it expects demand for Fable 5 to be very high and difficult to predict. And indeed some, like shopping rewards platform Rakuten, might think the upside is worth the price point. “At the highest effort, Fable reflects on and validates its own work,” Rakuten said in a statement. “For us, that’s what makes highly autonomous operations possible — the extra thinking pays for itself.”
Anthropic 表示，预计 Fable 5 的需求将非常高且难以预测。事实上，一些公司（如购物奖励平台 Rakuten）可能认为其带来的收益值得这个价格。“在最高负载下，Fable 会反思并验证自己的工作，”Rakuten 在声明中表示，“对我们来说，这正是实现高度自主运营的关键——额外的思考过程物有所值。”