Anthropic：寓言与神话（中英对照）

Today we’re launching Claude Fable 5: a Mythos-class¹ model that we’ve made safe for general use.

今天，我们正式发布 Claude Fable 5：一款经过安全处理、面向通用场景开放的 Mythos 级（Mythos-class）¹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面向公众开放的任何一款模型。在几乎所有受测的 AI 能力基准上，它都达到了业界最高水平，在软件工程、知识型工作、视觉、科学研究等众多领域展现出卓越表现。任务越长、越复杂，Fable 5 相对于我们其他模型的领先优势就越大。

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.

发布一款如此强大的模型也伴随着风险。若没有防护措施，Fable 5 在网络安全等领域的能力可能被滥用，造成严重危害。因此，我们在发布时为其配备了防护机制：涉及某些主题的请求，将转由我们能力次强的模型 Claude Opus 4.8 来作答。为了既安全又迅速地发布这款模型，我们把这些防护措施调得偏保守——它们有时会误拦无害的请求，不过平均而言，触发率低于 5% 的会话。随着未来几个月更强大的模型陆续问世，我们正努力改进防护措施，并尽快降低误报率。

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.² 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.

面向一小批网络防御者和基础设施提供方，我们同时发布 Claude Mythos 5。它与 Fable 5 是同一个底层模型，只是在某些领域解除了防护限制。²Mythos 5 最初将通过我们与美国政府合作的”玻璃翼计划”（Project Glasswing）部署，作为 Claude Mythos Preview 的升级版。它拥有全球任何模型中最强的网络安全能力。不久之后，我们计划通过一个范围更广的”可信访问计划”（trusted access program）来扩大 Mythos 5 的开放范围。

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，其能力有潜力为世界带来深远的福祉。我们已经在”玻璃翼计划”中看到了这种苗头——模型帮助网络防御者守护了至关重要的软件。我们也在生命科学研究中看到了这一点——模型正在提出新颖的假设，并加快新疗法的研发进程。

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 与 Mythos 5 的定价为：每百万输入 token 10 美元、每百万输出 token 50 美元——还不到 Claude Mythos Preview 价格的一半。今天这次联合发布，是我们朝着既定目标又迈进了一步：尽可能快、尽可能安全地，把先进的 AI 能力带给尽可能多的用户。

The table below compares the capabilities of Fable 5 and Mythos 5 to other leading models.

下表将 Fable 5 与 Mythos 5 的能力同其他领先模型进行了对比。

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.

Fable 5 与 Mythos 5 能够自主工作的时长超过以往任何一代 Claude 模型。下面我们将讨论这些能力如何应用于软件工程，并介绍模型在知识型工作、视觉、记忆以及生命科学研究方面的进步。

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 反馈说 Fable 5 把数月的工程量压缩到了几天。在一个 5000 万行的 Ruby 代码库中，模型用一天时间完成了一次全代码库的迁移——而这项工作若由整个团队手工完成，本需两个多月。Fable 5 在 token 使用上也比过去的 Claude 模型更高效：在 Cognition 的 FrontierCode 评测（该评测考查模型能否在满足高质量生产级代码库标准的前提下通过高难度编程任务）中，Fable 5 在各前沿模型里得分最高——哪怕只在”中等投入”（medium effort）档位下运行。

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.

知识型工作。Fable 5 在复杂分析任务上表现强劲。在 Hebbia 面向资深级别推理的金融基准（Finance Benchmark）中，Fable 5 取得了所有模型中的最高分，在基于文档的推理、图表解读以及问题求解方面均有大幅提升。IMC 指出，Fable 5 几乎在他们全部的交易分析评测中都拿到了满分级表现，涵盖事实查找、概念推理、根因分析与期望值分析。

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。在涉及视觉的任务上，Fable 5 是新一代业界最强模型。它能从精细的科学图表中提取出准确的数值，也能完成诸如仅凭截图还原 Web 应用源代码这样的复杂视觉任务。它所需的”脚手架”（scaffolding）也更少：举例来说，以往的 Claude 模型即便配上能提供额外辅助工具的运行框架，也很难玩转《宝可梦：火红》，而 Fable 5 仅靠一个极简的、纯视觉的运行框架就通关了《火红》。

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。在长时间运行的任务中，Fable 5 能在数百万 token 的跨度上保持专注，并借助自己记下的笔记来改进输出。当我们让模型去玩卡牌构筑类游戏《杀戮尖塔》（Slay the Spire）时，赋予它基于文件的持久化记忆，对其表现的提升幅度是 Opus 4.8 的三倍；Fable 进入游戏最终幕（final act）的频率也是后者的三倍。

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 operators. In doing so, the model executes all of the tasks that are normally completed by a scientist: choosing binding sites, selecting and running protein design tools, and recovering from failures along the way. Nine of the 14 protein targets from this study (shown below) yielded strong candidates for drug design that we’re currently investigating.

药物设计。借助 Mythos 5，我们内部的蛋白质设计专家把药物设计流程中的部分环节加速了约十倍。在一个案例中，他们发现：Mythos 5 在配备蛋白质设计与生物信息学工具、且无任何人类协助的情况下，表现可与熟练的人类操作者持平甚至更优。在此过程中，模型完成了通常由科学家来做的全部工作：选择结合位点、挑选并运行蛋白质设计工具，以及在途中从失败中恢复。在这项研究的 14 个蛋白质靶点（见下图）中，有 9 个产出了用于药物设计的有力候选物，我们目前正在对其展开进一步研究。

Novel hypotheses in molecular biology. Mythos 5 is our first model to consistently produce novel, compelling scientific hypotheses. In blinded head-to-head comparisons against Opus-class models, our scientists preferred Mythos’s molecular biology hypotheses ~80% of the time, and have advanced several to experimental evaluation. In the meantime, one Mythos hypothesis—a novel mechanism for an E. coli protein—was corroborated in a study from a lab independently working on the same problem.

分子生物学中的新颖假设。Mythos 5 是我们第一款能够稳定提出新颖且有说服力的科学假设的模型。在与 Opus 级模型进行的盲法正面对比中，我们的科学家约有 80% 的情况更青睐 Mythos 提出的分子生物学假设，并已将其中数项推进到了实验验证阶段。与此同时，Mythos 提出的一项假设——关于某种大肠杆菌（E. coli）蛋白的新颖机制——在一个独立研究同一问题的实验室所做的研究中得到了印证。

Novel research in genomics. Mythos 5 conducted novel genomics research in over a week of largely autonomous work. It assembled single-cell data for millions of cells spanning 138 animal species and designed and trained a custom machine learning model to identify cells performing the same role in even distantly related organisms. With only high-level human input, Mythos 5’s trained model outperformed a recent model published in the journal Science—despite being 100 times smaller. We intend to publish these results in the coming months.

基因组学中的原创研究。Mythos 5 在长达一周多、基本自主的工作中完成了一项原创的基因组学研究。它整合了横跨 138 个动物物种、数以百万计细胞的单细胞数据，并设计、训练了一个定制的机器学习模型，用以识别在亲缘关系即便很远的生物体中扮演相同角色的细胞。在仅有高层级人类输入的情况下，Mythos 5 训练出的模型表现胜过了近期发表在《科学》（Science）期刊上的一个模型——尽管其体量只有后者的百分之一。我们计划在未来几个月内发表这些成果。

Alignment. In our automated alignment assessment we found that Mythos 5’s level of misaligned behavior (including misaligned actions taken by the model such as deception, and cooperation with misuse of the model by a user) was low, and similar to that of Opus 4.8. Given they are the same underlying model, Fable 5’s level of alignment will be similar. The assessment is described in full, along with a detailed suite of other safety and capabilities tests, in the model’s system card.

对齐（Alignment）。在我们的自动化对齐评估中，我们发现 Mythos 5 的失准行为（misaligned behavior，包括模型自身采取的失准行动，如欺骗，以及配合用户对模型的滥用）水平较低，与 Opus 4.8 相当。鉴于二者是同一个底层模型，Fable 5 的对齐水平也将与之相近。这项评估，连同一整套其他安全与能力测试的详细内容，已在该模型的系统卡（system card）中完整记述。

Customers with early access ran their own tests on Fable 5. Below, in their words, is a selection of what they’re seeing:

获得早期访问权限的客户对 Fable 5 进行了各自的测试。以下精选了他们的原话反馈：

Mythos-class models have reached a threshold where they present significant risks. In April we began Project Glasswing, releasing the first Mythos-class model (Claude Mythos Preview) to only a limited group of cyber defenders and critical software infrastructure providers. When we did so, we stated that we hoped to eventually release Mythos-level capabilities to all our users, so long as we had developed new safeguards that were strong enough to reliably prevent misuse.

Mythos 级模型的能力已经达到了一个会带来重大风险的临界点。今年 4 月，我们启动了”玻璃翼计划”，将首款 Mythos 级模型（Claude Mythos Preview）仅向一小批网络防御者和关键软件基础设施提供方开放。当时我们就表示，希望最终能把 Mythos 级别的能力开放给所有用户——前提是我们已经开发出足够强、能够可靠防止滥用的新防护措施。

Over the past few months we have been improving these safeguards, and they are now robust enough for a general release. Because we have prioritized safety, we’ve deliberately tuned the safeguards to be cautious, and they are still stricter than would be ideal—for example, sometimes benign requests will trigger our classifiers. We recognize that this will be frustrating to some users, and our aim is to reduce false positives as we update and refine the safeguards after launch.

过去几个月里，我们一直在改进这些防护措施，如今它们已经足够稳健，可以支撑面向公众的发布。由于我们把安全放在首位，便有意把防护措施调得偏谨慎，它们目前仍比理想状态更严格——比如，有时无害的请求也会触发我们的分类器。我们清楚这会让部分用户感到困扰，我们的目标是在发布后不断更新和打磨防护措施，逐步降低误报率。

Below we discuss each of Fable 5’s new safeguards in turn. Our wider suite of safeguards is discussed and evaluated in the model’s system card and our most recent risk report.

下面我们逐一介绍 Fable 5 的各项新防护措施。我们更完整的防护体系，已在该模型的系统卡以及我们最新的风险报告中进行了讨论与评估。

The frontier cybersecurity and research biology capabilities of Mythos-class models mean that they pose a substantial risk of uplift to malicious actors. That is, these models could provide information or advice that assists those actors in causing serious harm that they couldn’t have received from other sources (for example, from internet search engines). Furthermore, a great deal of advanced usage of AI models is dual use: the same queries that are beneficial in the hands of cybersecurity professionals and biology researchers could be dangerous if available to malicious actors.

Mythos 级模型在前沿网络安全和研究型生物学上的能力，意味着它们存在为恶意行为者提供显著”能力跃升”（uplift）的重大风险。也就是说，这些模型可能提供某些信息或建议，帮助这些行为者造成他们本无法从其他渠道（例如互联网搜索引擎）获得的严重危害。此外，对 AI 模型的许多高级用法都是”军民两用”（dual use）的：同样的查询，在网络安全专家和生物学研究者手中是有益的，可一旦落到恶意行为者手里就可能变得危险。

We therefore need strong safeguards to prevent misuse, and their coverage needs to be broad. The safeguards themselves have to stand up to sustained and sophisticated attempts to bypass them (also known as “jailbreaking” the system). The uplift from Mythos-level capabilities is valuable to many adversaries—for instance, those who could financially gain from cyberattacks—and we therefore expect them to be motivated to try to circumvent our safety measures.

因此，我们需要强有力的防护措施来防止滥用，而且其覆盖面必须足够广。防护措施本身必须经得起持续而精巧的绕过尝试（也就是所谓的对系统”越狱”，jailbreaking）。Mythos 级别能力所带来的跃升，对许多对手都极具价值——比如那些能从网络攻击中获取经济利益的人——因此我们预计他们会有强烈动机去设法规避我们的安全措施。

Fable 5 comes with a new set of classifiers: separate AI systems that detect potential misuse, including jailbreak attempts, and prevent the main model (in this case Fable 5) from responding. We’ve been running classifiers on our models for some time, and Fable 5’s classifiers are an extension of this previous work with extra coverage.

Fable 5 配备了一套全新的分类器：它们是独立的 AI 系统，用于检测潜在的滥用（包括越狱尝试），并阻止主模型（此处即 Fable 5）作答。我们在模型上运行分类器已有一段时间，Fable 5 的分类器正是在这一既有工作基础上的延伸，并扩大了覆盖范围。

When Fable’s classifiers detect a request related to cybersecurity, biology and chemistry, or distillation, the response is automatically handled by Claude Opus 4.8 instead. Users will be informed whenever this occurs. Opus 4.8 is a highly capable model in its own right: a response that falls back to Opus is a far better experience than an outright refusal from Fable. Our early data shows that more than 95% of Fable sessions involve no fallback at all—for those sessions, Fable 5’s performance is effectively the same as that of Mythos 5.

当 Fable 的分类器检测到与网络安全、生物与化学，或模型蒸馏（distillation）相关的请求时，应答会自动改由 Claude Opus 4.8 来处理。每当发生这种情况，用户都会被告知。Opus 4.8 本身就是一款能力很强的模型：相比 Fable 直接拒答，回退（fall back）到 Opus 的体验要好得多。我们的早期数据显示，超过 95% 的 Fable 会话根本不会触发任何回退——对这些会话而言，Fable 5 的表现实际上与 Mythos 5 别无二致。

The following are the areas covered by the classifiers:

以下是这些分类器所覆盖的领域：

We extensively red-teamed our classifiers to test their robustness against jailbreaks. As well as internal testing, we ran an external bug bounty that produced no universal jailbreaks in over 1,000 hours of testing. External red-teaming organizations we engaged also failed to find any universal jailbreaks on long-form agentic tasks so far—although the UK AISI has made progress towards one within a brief initial testing window.⁴ It is likely impossible to completely prevent universal jailbreaks, but our goal is to make any remaining jailbreaks sufficiently slow and costly that we can detect and prevent them before they are used at scale.

我们对分类器进行了大量的红队测试，以检验它们抵御越狱的稳健性。除内部测试外，我们还开展了一项外部漏洞赏金活动，在超过 1000 小时的测试中没有产生任何”通用越狱”（universal jailbreak）。我们所聘请的外部红队机构，迄今也未能在长篇智能体任务上找到任何通用越狱——尽管英国 AI 安全研究所（UK AISI）在一个短暂的初步测试窗口内，已朝着发现一例通用越狱取得了一些进展。⁴要完全杜绝通用越狱很可能是不可能的，但我们的目标是让任何残留的越狱都足够缓慢、足够高成本，以便我们能在它们被大规模利用之前及时发现并加以阻止。

One of our external partners found that Fable 5’s safeguards against harmful cyber queries were the most robust of any model tested (including Opus 4.8 and Opus 4.7). Fable 5 complied with zero harmful single-turn requests relating to planning a cyberattack, exploit development, or defense evasion. This held whether or not one of the requests used any of 30 different public jailbreak techniques.

我们的一家外部合作伙伴发现，Fable 5 针对有害网络查询的防护措施，是所有受测模型（包括 Opus 4.8 和 Opus 4.7）中最稳健的。对于涉及策划网络攻击、漏洞利用开发或防御规避的有害单轮请求，Fable 5 的服从率为零。无论请求是否用上了 30 种不同的公开越狱技术中的任何一种，这一结论都成立。

On biology and chemistry: for example, we tested Mythos 5’s ability to complete a challenging step in designing adeno-associated viruses (AAVs). AAVs are a component for delivering gene therapies, but the same capability, in the wrong hands, could enable the design of dangerous viruses. In this task, various AI models were evaluated on their ability to predict how a genetic modification would impact the assembly of the virus’s outer shell (among a set of therapeutically-relevant unpublished candidates developed by Dyno Therapeutics). We did not explicitly train our models to perform this task—and yet Mythos-class models outperformed sophisticated models dedicated to protein tasks (known as “protein language models”) using their biological reasoning alone. This demonstrates a promising ability to complete simple but important tasks in gene therapy research and development—but also highlights the risk posed by such dual-use capabilities.

关于生物与化学：举例来说，我们测试了 Mythos 5 完成腺相关病毒（AAV）设计中一个高难度步骤的能力。AAV 是递送基因疗法的一种载体组件，但同样的能力一旦落入不法之手，也可能被用于设计危险的病毒。在这项任务中，多款 AI 模型被评估其预测能力：一项基因改造会如何影响病毒外壳的组装（测试对象是 Dyno Therapeutics 开发的一组与治疗相关、尚未发表的候选物）。我们并没有专门训练模型来完成这项任务——然而 Mythos 级模型仅凭其生物学推理，表现就胜过了那些专门用于蛋白质任务的精密模型（即所谓的”蛋白质语言模型”）。这既展现出其在基因疗法研发中完成简单但重要任务的可观潜力——也凸显了此类两用能力所带来的风险。

Our priority was to safely release Fable as soon as we could, even at the cost of overly broad safeguards. Therefore, for the time being we have arranged for Fable to fall back to Opus 4.8 on most requests related to biology and chemistry. As with all of our classifiers, we hope to narrow these safeguards as soon as possible: as can be seen from the evidence above, there is great potential for positive applications of Fable for science, and we do not want false positives from our classifiers to get in the way. In the coming weeks, some biomedical researchers and companies will be able to join our trusted access program for biology capabilities in Mythos 5 (discussed below).

我们的首要任务，是尽可能快地安全发布 Fable，哪怕代价是防护措施过于宽泛。因此，目前我们已安排 Fable 在大多数与生物和化学相关的请求上回退到 Opus 4.8。与我们所有的分类器一样，我们希望尽快收窄这些防护措施：正如上述证据所示，Fable 在科学领域有着巨大的正面应用潜力，我们不希望分类器的误报成为绊脚石。未来几周内，部分生物医学研究者和企业将能够加入我们针对 Mythos 5 生物能力的可信访问计划（详见下文）。

Finally, we’re making a change to the way we handle business customer data for Fable 5, Mythos 5, and future models with similar or higher capability levels. We will require 30-day retention for all traffic on Mythos-class models, on both first- and third-party surfaces. We won’t use this data to train new Claude models, or for any non-safety-related purpose, and we’ve instituted new privacy protections including logging all human access to the data and ensuring its deletion after 30 days in almost all cases (see this post for further details). The data will help us defend against complex and novel attacks (including new jailbreaks and attacks that operate across many requests) as well as help us identify and reduce false positives.

最后，针对 Fable 5、Mythos 5 以及未来具有相近或更高能力水平的模型，我们将调整对企业客户数据的处理方式。我们将要求对 Mythos 级模型上的所有流量保留 30 天，无论是第一方还是第三方界面。我们不会用这些数据来训练新的 Claude 模型，也不会用于任何与安全无关的目的；同时我们已经设立了新的隐私保护措施，包括记录所有对这些数据的人工访问，并确保在几乎所有情况下数据都会在 30 天后删除（更多细节见相关文章）。这些数据将帮助我们抵御复杂而新颖的攻击（包括新的越狱手法，以及横跨多次请求展开的攻击），同时也有助于我们识别并减少误报。

Beginning today, all users who currently have access to Claude Mythos Preview (for example, our cybersecurity partners in Project Glasswing) will be able to upgrade to Claude Mythos 5—the same model as Claude Fable 5 but with cyber safeguards lifted. Users will find Mythos 5 comparable to, or somewhat stronger than, Mythos Preview in most cases, while costing substantially less.

从今天起，所有当前已能访问 Claude Mythos Preview 的用户（例如”玻璃翼计划”中的网络安全合作伙伴），都将能够升级到 Claude Mythos 5——它与 Claude Fable 5 是同一款模型，只是解除了网络方面的防护限制。在大多数情况下，用户会发现 Mythos 5 与 Mythos Preview 相当、或略强于后者，而成本却大幅降低。

In consultation with the US government, we plan to steadily expand access to Claude Mythos 5, continuing our periodic addition of new partners, as well as pursuing a trusted access program that allows cybersecurity organizations to apply in a more systematic manner.

在与美国政府协商的基础上，我们计划稳步扩大 Claude Mythos 5 的开放范围：一方面继续定期增加新的合作伙伴，另一方面推进一项可信访问计划，让网络安全机构能够以更系统化的方式提出申请。

Our plans also include opening a trusted access program for biology, to help accelerate biomedical research and discover new therapies with Mythos-class capabilities. This program will provide access to Fable 5 with the biology and chemistry safeguards removed (but the cyber safeguards still in place). It will enroll a small number of researchers from a variety of life science organizations spanning fundamental and translational research; we’re planning to expand access to this program while simultaneously making our safeguards better.

我们的计划还包括开放一项面向生物学的可信访问计划，借助 Mythos 级能力来加速生物医学研究、发现新的疗法。该计划将提供解除了生物与化学防护限制（但仍保留网络防护）的 Fable 5 访问权限。它将吸纳来自各类生命科学机构、横跨基础研究与转化研究的少量研究者；我们计划一边扩大该计划的开放范围，一边同步把我们的防护措施做得更好。

Claude Fable 5 is available everywhere today. Claude Mythos 5 is restricted to Glasswing partners (with cyber safeguards lifted) and soon to select biology researchers (with biology and chemistry safeguards lifted) only, until our broader trusted access program is available.

Claude Fable 5 自今日起在所有渠道开放使用。Claude Mythos 5 则仅限于”玻璃翼计划”的合作伙伴（解除网络防护）以及即将加入的少数生物学研究者（解除生物与化学防护），直至我们更广泛的可信访问计划开放为止。

Pricing for both models is $10 per million input tokens and $50 per million output tokens. Developers can use claude-fable-5 via the Claude API.

两款模型的定价均为：每百万输入 token 10 美元、每百万输出 token 50 美元。开发者可通过 Claude API 使用 claude-fable-5。

We expect demand for Fable 5 to be very high, and difficult to predict. On the Claude API and consumption-based Enterprise plans, Fable 5 is fully available from today. For subscription plans, we’d rather give access sooner than later, so we’re rolling out more conservatively, in stages:

我们预计 Fable 5 的需求会非常高，且难以预测。在 Claude API 和按用量计费的企业版（Enterprise）方案中，Fable 5 自今日起完全开放。对于订阅制方案，我们宁可早一点开放也不愿拖延，因此采取更为审慎的分阶段推出策略：

Throughout this period, we’ll communicate any changes ahead of time so users know where things stand.

在整个过渡期内，我们都会提前沟通任何变动，好让用户随时了解最新情况。