Claude Fable 5

Anthropic's June 30, 2026 redeployment post explains that on June 12 the US government applied export controls to Claude Fable 5 and Claude Mythos 5, requiring nationality-based access restrictions; because real-time nationality verification was not feasible, Anthropic suspended access for all users on both models. As The post also covers Anthropic's safeguards approach using safety classifiers to detect potentially dangerous cybersecurity uses, outlines a timeline of events and safeguard updates, and announces a joint industry framework with Amazon, Microsoft, Google, and other Glasswing partners to standardize jailbreak severity a

An independent benchmark and specifications recap confirms Claude Fable 5 was released on June 9, 2026, as the first Mythos-class model Anthropic has made generally available, posting state-of-the-art results across software engineering, knowledge work, scientific research, and vision benchmarks. The API model ID is cl Fable 5 is described as "Mythos made safe," with a separate classifier system monitoring every session for high-risk cybersecurity, biology, chemistry, and distillation requests and rerouting flagged requests to a category-appropriate fallback model such as Opus 4.8 for cybersecurity or Opus 5 for biology, with the use

Explainx.ai's September 2, 2026 breakdown of the September 1-2 joint release covers Claude Fable 5.1 as the generally available model and Claude Mythos 5.1 as the same weights with select safeguards lifted for vetted cybersecurity and life-sciences users via Project Glasswing. It reports headline benchmarks including T On pricing, input/output remain $10/$50 per million tokens while cache reads drop 75% from $1.00 to $0.25, yielding an estimated 25% cost reduction for typical workloads and up to 45% for highly agentic work. A new Enterprise Frontier Safeguards (EFS) feature with customer-cloud data retention is rolling out in fall 20

Anthropic's official Claude Fable product page documents the model's evolution across 2026: the June 9 launch of Claude Fable 5 (5th generation for the most ambitious work, handling days-long complex tasks), a June 12 access disruption, a July 1 access restoration, an August 6 biology-safeguards update reducing false p The page specifies Fable 5.1 availability on Pro, Max, Team, and Enterprise plans, plus the Claude Platform, AWS, Google Cloud, and Microsoft Foundry, with US-only inference available at 1.1x pricing. API pricing is $10 per million input tokens and $50 per million output tokens, with cache reads cut 75% to $0.25 per mi

Releasebot's August 21, 2026 Anthropic index aggregates recent updates, including the expansion of Claude Mythos 5 cybersecurity capabilities into Claude Security for Enterprise, adding codebase scanning, vulnerability findings, and suggested patches for defenders. It also notes a $35M Defender Advantage Fund to help s The update describes how the riskiest behavior occurs with direct model access, so the announced changes expand access to defensive outputs such as patches and security alerts while keeping guardrails around direct usage. Claude Mythos 5 is reported as now available in Claude Security and coming soon to partners' cyber

This kie.ai analysis covers Claude Fable 5.1, which Anthropic officially launched on September 1, 2026 alongside Claude Mythos 5.1, positioned for coding and knowledge work. Confirmed headline pricing is reported as $10 per million input tokens and $50 per million output tokens, with cache reads falling 75% from Fable The piece functions as a retrospective on pre-launch speculation versus what actually shipped, noting that community discussion, account testing reports, and support-document sightings correctly pointed toward unchanged headline pricing and a focus on long-horizon reasoning and agent work, but were not the product docu

Claude Fable 5 is a Mythos-class model from Anthropic, built for autonomous knowledge work and coding. $10 per million input tokens, $50 per million output tokens. 1,000,000 token context window, maximum output of 128,000 tokens. Higher uptime with 4 providers. Includes independent benchmarks from Artificial Analysis.

June 9, 2026. Claude Fable 5 launch. We launched Claude Fable 5, a Mythos-class model that we've made safe for general ...

On June 9, 2026, Anthropic publicly released Claude Fable 5 as its first generally available model from a new Mythos-class tier that sits above Opus, while keeping Claude Mythos 5 restricted to approved cyberdefense and infrastructure partners via Project Glasswing. According to the Coursiv aggregator citing Anthropic Fable 5 and Mythos 5 share the same underlying model, with Fable 5 adding stricter safety classifiers in cybersecurity, biology, chemistry, and model distillation to make it safe for broad release. Adaptive thinking is always on with summarized rather than raw chain-of-thought output, and best-use framing targets auton

Anthropic has abruptly walked back a controversial, unannounced policy that degraded the performance of its latest model, Claude Fable 5.

On June 9, 2026, Anthropic launched Claude Fable 5, a model designed for long-horizon tasks, but it was taken offline shortly after due to a U.S. government export directive. It shares architecture wi

This third-party explainer covers Anthropic's June 9, 2026 launch of Claude Fable 5 alongside Claude Mythos 5, both positioned in a newly introduced Mythos-class tier that sits above Opus in capability. The article describes Fable 5 and Mythos 5 as Anthropic's most capable models to date, built for long-horizon agentic The article situates Claude Fable 5 within Anthropic's naming history, noting the Opus/Sonnet/Haiku structure dates to the Claude 3 generation in March 2024 and that Mythos-class is the first new capability tier added above Opus since then. It emphasizes that Fable 5 and Mythos 5 represent a qualitative rather than inc