fable

On November 10, the B.AI platform announced the official launch of Anthropic Claude Fable 5.2, with API and Web Chat available simultaneously. This model is designed for complex reasoning, software engineering, and long-cycle agent workflows, always enabling adaptive thinking, equipped with a 1M Token ultra-large context window and a maximum output of 128K Tokens.According to the Artificial Analysis Intelligence Index v5 rating, Claude Fable 5.2 topped the list with a score of 65 under the highest configuration, far exceeding the median score of 40 among similar models. The generation speed has improved by up to 30% compared to Fable 5.1, with a standard price of $8.00 per million input Tokens and $40.00 per million output Tokens, and it supports prompt caching. You are welcome to log in to chat.b.ai/chat to experience it.

Renowned developer and T3 Code founder Theo discovered that although Anthropic's newly released Fable 5.2 is more powerful, the API equivalent usage available to subscription users is significantly lower. Theo has been tracking the actual request data of Claude Code for a long time. According to his estimates, for the same monthly subscription fee of $200 for Claude Ultra, using Opus 5.5 would yield an API usage equivalent to about $15,000 per month; switching to Fable 5.2 would only provide about $3,000, a difference of nearly 5 times.Anthropic stipulates that Ultra users can use a maximum of 50% of their total quota for Fable each week. Even if the entire quota is not used, as long as Fable reaches its limit, users must switch to other models or pay extra to continue using it. Theo estimates that if Opus 5.5 is used fully in a week, approximately 1,200 interaction rounds and 230 task sessions can be completed. If the Fable quota is exhausted first and then switched to Opus, the total number of interaction rounds would drop to about 900, although the number of completed task sessions might be slightly higher since Fable can sometimes complete tasks in one go without repeated communication.The API unit price of Fable 5.2 has decreased by 20% compared to the previous generation, with input and output tokens costing $8 and $40 per million, respectively, but it is still twice that of Opus 5.5. Anthropic reminds users that Fable will consume subscription quotas faster than other Claude models. Currently, Anthropic is offering eligible subscription users 1 to 3 opportunities to reset their Fable quota, with the number of resets depending on the subscription duration. Each reset can return the Fable quota consumed in the current week, allowing users to continue using it without waiting until the next week.

Anthropic released Claude Fable 5.2 and the restricted version Mythos 5.2 on Monday, stating that the new model can transform a small number of instructions into runnable software, design physical objects, and address research questions that previously required a professional team. The official announcement claims that its output speed has improved by up to 30% compared to the previous generation, with Fable 5.2 scoring 49.1% in the internal FrontierCode 2 evaluation, higher than Fable 5.1's 32.4%. Both share the same underlying model, with Fable having stricter protections against dangerous biological and cybersecurity requests, while Mythos is only open to certified institutions in relevant fields.In terms of pricing, the standard API price is $8 per million input tokens and $40 per million output tokens, lower than the previous generation's $10 and $50; an optional fast mode can increase output speed by up to 2.5 times, but the rates double to $16 and $80. In comparison, Kimi 3.1 Pro is priced at $2 and $10, while the latest DeepSeek model is $0.6 and $1.98 during off-peak hours.AI blogger Matthew Berman's tests show that Fable 5.2 can generate playable games and a browser version of Excel. One level styled after "Gears of War" took 43 hours and 48 minutes to complete, consuming 8.63 billion tokens, with an estimated cost of $14,710 based on developer pay-per-use estimates; the Excel clone is estimated at about $11,700, and a "Fall Guys" style game ran for 71 hours, consuming over 9 billion tokens, approximately $13,000. Anthropic provides one week of Fable access for Pro users and standard Team seats, capped at half of the weekly quota, with promotional access for Pro users ending on November 16.

According to Beating AI's news, a summary of an expert interview circulating in the investment community states that the next-generation foundational model of the artificial intelligence company Zhipu is not the previously rumored 1.6 trillion parameters, but rather between 2.5 trillion and 3.5 trillion parameters. The GLM-5.3 released by Zhipu in August this year still uses the previous generation foundational model, with a total of approximately 744 billion parameters; if the information is true, the new foundational model's scale is about 3.4 to 4.7 times that of the current one.The summary also states that the training has not gone smoothly, as Zhipu adopted a more aggressive model architecture, and during the pre-training period, there was a time when the loss did not decrease, meaning that computational power was continuously invested but training metrics could not continue to improve. The interviewee believes that the problem should have been resolved recently, and training is expected to be completed soon, predicting that the new model can reach flagship levels comparable to Claude Fable.The summary further mentions that the new model has taken inference speed and cost as hard constraints from the architectural design stage, with the goal of being able to provide services on a large scale from the first day of release. At the same time, multiple cloud vendors are negotiating revenue sharing to address the issue of large models being produced but not being able to supply.

On Tuesday, Anthropic released Claude Opus 5.5, the first model in its Claude 5.5 series. Anthropic stated that the new model's performance on most tasks has reached the level of its most expensive flagship model, Claude Fable 5.1, but the operating costs are 20% lower than the previous generation Opus 5 and 60% lower than Fable 5.1. In terms of pricing, the input and output token prices for Opus 5.5 are $4 per million and $20 per million, respectively, while the cache read price has dropped to $0.2 per million.In benchmark testing, Opus 5.5 scored 66.4% on Terminal-Bench 4, higher than Fable 5.1's 55.8% and GPT-6 Astra's 57.9%; FrontierCode scored 54.4%, higher than Fable 5.1's 50.3%; GDPval-AA v2.1 scored 1846, higher than Fable 5.1's 1735. However, GPT-6 Astra still leads Opus 5.5 in the AutomationBench and Terminal-Bench-Science 0.1 tests.This is the first model released after Anthropic CEO Dario Amodei called on the industry to slow down the pace of AI capability enhancement, and it continues to use the same cybersecurity and biosafety measures as Fable 5.1.

Elon Musk stated on social media that Grok 4.7 is roughly equivalent to Opus 5, rather than 5.1. Grok 4.8 will bring significant improvements, and Grok 4.9 may reach Astra/Fable levels. Grok 5 may surpass all current products.

B.AI platform announces that Anthropic's latest Mythos-level general model Claude Fable 5.1 is now officially integrated with the API.This model uses the same underlying model as Claude Mythos 5.1, specifically optimized for high-intensity coding, long-term agent workflows, and complex knowledge tasks. It achieved an excellent performance of 73.4% at maximum computational intensity in the CursorBench 3.2.0 test.API access is now open, and developers can enjoy exclusive discounts—official channels as low as 15% off, and self-selected service providers as low as 40% off. B.AI continues to introduce top global models, providing developers with more powerful and cost-effective AI capability options.

On September 1, Anthropic released Claude Fable 5.1 and Claude Mythos 5.1, marking the first update to this model series since the launch of Fable 5 on June 9. Anthropic claims that the new models are the most advanced for programming and knowledge work. In the Terminal-Bench-Science 0.1 benchmark, Fable 5.1 recorded a pass rate of 52.6%, more than doubling Fable 5's 24.7% and surpassing Opus 5's 29%; in Terminal-Bench 4, Fable 5.1 scored 55.8%, higher than Fable 5's 42% and Opus 5's 52.3%.Fable 5.1 and Mythos 5.1 share the same underlying model, differing only in their safety filters. Fable 5.1 is available to all Claude accounts, while Mythos 5.1 remains restricted to professionals vetted through Anthropic's network security verification program and life sciences verification program. In terms of pricing, Fable 5.1 charges $10 per million tokens for input and $50 for output, which is double that of Opus 5. Cache read costs have decreased by 75%, and typical workload costs can drop by about 25%, with high agentic workloads decreasing by up to 45%.

According to GMGN data, the market capitalization of the Robinhood ecosystem Meme coin fable briefly surpassed 8.5 million dollars, with a 24H increase of over 990 times. It is reported that this project is an experimental initiative launched by AI-generated artist Kevin Ngo.The core narrative is that developers allow the AI Agent (Claude Fable 5) to autonomously build websites and issue tokens, symbolizing an unfinished story. According to market news, the price of Meme coins is highly volatile and easily influenced by market sentiment and trending events, so please be aware of trading risks.

On August 24, according to the Financial Times, Anthropic's U.S. corporate clients are reducing their use of its most powerful model, Fable5, opting instead for lower-priced alternative models, raising concerns about its high-investment business model. Anthropic is currently preparing for an IPO, with the market expecting its valuation to reach $2 trillion or more, potentially listing as early as September.Data from Ramp on spending by 70,000 companies shows that two months after the release of Fable5, corporate spending on this model accounted for only about 11% of Anthropic's total tool spending, and has recently stabilized. Analysts believe the main reason is that Fable5 is expensive, while older models can meet the needs of most companies; the Opus5 launched at the end of July is smaller and cheaper, with corporate spending already exceeding that of Fable5. Fable5 was withdrawn shortly after its release in early June due to intervention by the Trump administration on national security grounds, and was allowed to go back online on July 1, but demand and adoption rates remain lower than those of previous cutting-edge models.Anthropic's annualized revenue reached $65 billion last month, up from $47 billion in May, growing nearly sevenfold since the beginning of the year; the company achieved adjusted operating profit for the first time in the second quarter and has 6,000 clients with annual spending exceeding $100,000. Companies are controlling AI spending by choosing models with better cost-performance ratios, while OpenAI has seen a rebound, with annualized revenue growing 35% this quarter after the release of GPT5.6, exceeding $40 billion. The market is shifting from "chasing the strongest model" to placing greater emphasis on a comprehensive balance of model capability, price, and actual ROI.

Fireworks AI released an evaluation report comparing the open-source model Kimi K3 and the closed-source model Fable 5 across approximately 1030 agent tasks (covering scenarios such as SWE, terminal operations, algorithms, multilingual coding, and legal matters). The results showed that the accuracy rates for the two models on the SWE benchmark were 92.4% and 92.6%, respectively, indicating similar overall performance, but each model has its strengths in specific areas: K3 leads in symbolic mathematics and development tools, while Fable excels in web and data visualization; in long-cycle terminal tasks, K3 independently tackled 11 tasks that Fable could not solve.The report pointed out that adopting a task-level routing strategy can dynamically allocate between the two, achieving an accuracy rate of 93%, surpassing either single model. Additionally, due to K3's significant cost advantage on the Fireworks platform, costs for long-cycle agent tasks can be up to 50 times lower than Fable. The report recommends using the open-source model as the default option and continuously learning the optimal match between tasks and models through routers to balance quality and cost.

After Anthropic completed the global security policy adjustment and redeployed Claude Fable 5, the AI infrastructure platform B.AI has promptly completed the integration and fully restored support for related API calls. It is reported that this restoration not only ensures the stable operation of the underlying model but also continues to provide a dual-channel model of "official" and "self-selected service providers," aiming to flexibly adapt to the computing power and cost needs of developers and enterprise users in different scenarios. Currently, this service has officially launched on the B.AI official website for user experience.

According to Reuters, the U.S. Department of Commerce has officially lifted export controls on two AI models from Anthropic, Claude Fable 5 and Mythos 5, less than three weeks after the restrictions were imposed. Anthropic stated that access to the aforementioned models will be restored the following day.Previously, on June 12, Anthropic was forced to urgently take down the two models due to national security risks; on June 27, the U.S. government partially lifted the ban, allowing Mythos 5 to be accessible to certain "trusted" U.S. institutions. U.S. Secretary of Commerce Howard Lutnick stated that the government has closely collaborated with Anthropic over the past two weeks to complete the review and approval of Fable 5, ensuring it aligns with the overall stance of the U.S. government and strengthens the country's leadership position in the AI field.

Elon Musk responded to the community's question about when China will reach Fable-level AI, stating: "Maybe Q1."Previously, X user Teortaxes mentioned that GLM 5.2 currently shows a gap of about 7 months compared to cutting-edge models, generally at the level of Opus 4.7-4.8; Mythos has reached Preview status in early February 2026, and the complete PRC Mythos ("Fable") may be launched between November and December 2026.

David Sacks, the head of AI and crypto affairs at the White House, stated that although the commercial version of the Mythos series model Fable released by Anthropic this week includes safety barriers, once those barriers are bypassed, users will be able to access Mythos's advanced cyber attack capabilities. Sacks pointed out that Anthropic had previously described Mythos as a "cyber weapon" that requires regulation, so fixing the related vulnerabilities should have been its responsibility.Sacks mentioned that a partner trusted by both Anthropic and the U.S. government discovered a jailbreak method to bypass the safety barriers while testing Fable. The U.S. government subsequently requested Anthropic CEO Dario Amodei to fix the vulnerabilities or take the model offline, but this request was refused. Anthropic stated in a declaration that the vulnerability is "not serious," a claim that contradicts the judgment of the U.S. government and relevant partners.Sacks stated that Anthropic has always emphasized that safety should be prioritized, but this time it prioritized maintaining consumer-grade model services. In response, the U.S. government reluctantly imposed export control measures on Anthropic and hopes that Anthropic will resolve the safety issues as soon as possible to lift the related restrictions and restore the full release of Fable.Sacks also denied that this action is related to previous disputes between the U.S. Department of Defense and Anthropic, stating that the government recognizes Anthropic's technological capabilities and believes that the current issues can be resolved relatively easily, with the initiative currently in Anthropic's hands.

According to an official statement from Anthropic, on June 11 local time, the U.S. government issued an export control directive citing national security, requiring the suspension of access to Fable 5 and Mythos 5 for all foreign nationals. Anthropic was forced to shut down the aforementioned two models for all users.The government believes it has discovered a "jailbreak" method to bypass the protective mechanisms of Fable 5, but Anthropic, after review, pointed out that the related vulnerability is relatively minor and that similar capabilities exist in other publicly available models such as OpenAI GPT-5.5, which does not constitute an exclusive risk to Mythos.Anthropic stated that it will comply with the government directive but clearly opposes taking down commercial models that have been deployed to hundreds of millions of users based on the discovery of a single narrow-range jailbreak. They warned that if this standard is widely applied in the industry, it would effectively block all new deployments of cutting-edge models. The company is currently actively communicating with the government to restore access as soon as possible.