Claude Fable 5, Anthropic’s latest frontier model, is available today in Microsoft Foundry, powering agents in GitHub Copilot and Foundry Agent Service. Claude Fable 5 makes Mythos-level capabilities available to all customers, with strong safeguards designed to make it safe for general use.

Fable 5 is designed for long-running, multi-stage, and asynchronous tasks like complex code refactoring, deep research synthesis, and document-heavy workflows. This elevated level of autonomy changes what teams can ask AI to do. Enterprises can now delegate sophisticated multi-turn projects to agents, enabling them to reason over your organization’s data to solve real problems.

For enterprises, this frontier capability is only part of the equation. To turn autonomy into real business impact, organizations need a platform to evaluate, ground, govern, deploy, and scale these systems in production.

That is where Microsoft Foundry comes in. Foundry brings Anthropic’s next generation of intelligence into the broader Microsoft agent platform, helping enterprises build ambitious, high-impact AI solutions on Azure with the security, governance, reliability, and operational controls required for real business workflows.

Combined with Microsoft IQ, Fable 5 can reason over your team, your knowledge, and your data across Power BI, your applications, and the web, with a continuously updating view that learns as usage grows.

The next generation of frontier intelligence

According to Anthropic, Claude Fable 5 is the next generation of intelligence for the hardest knowledge work and coding problems. It can handle tasks previous models couldn’t sustain and represents a step change in what teams can hand off to Claude.

Claude Fable 5 can plan its approach, check progress against the goal, and refine its work as it goes, instead of waiting for the next instruction. This makes it well suited for complex coding tasks, research workflows, and long-running knowledge work where the model needs to reason across multiple steps.

With improved vision capabilities, Claude Fable 5 is also a strong fit for multimodal projects involving documents, PDFs, diagrams, charts, and dense tables. It does not just read the words on a page; it can interpret the meaning carried by visual and structured information. When critical context is embedded in a chart, schematic, or complex table, Claude Fable 5 can take it in and reason over it, helping finance, legal, analytics, and architecture teams work through material that is often reviewed manually today.

Claude Fable 5 real-world enterprise use cases

For business leaders, Claude Fable 5 changes how knowledge work is accomplished across the organization. Fable 5 is a frontier general-purpose model designed to help support complex, cross-functional tasks that span reasoning, creation, and execution.

Key enterprise use cases include:

• Software development: Supporting demanding coding and system-level builds that stretch across days and stages, by carrying context from analysis through implementation and review.
• Financial services: Building investment research, working through earnings, weighing credit and risk, and supporting compliance workflows—including the numbers locked inside long filings and their exhibits.
• Legal: Marking up and reviewing contracts, streamlining due diligence, digging through case law, and producing first-pass motions and memos.

Beyond these, Claude Fable 5 also carries professional work across marketing, sales, and analytics, shaping strategy, drawing out insight, and turning it into decision-ready output as part of connected, end-to-end workflows.

Built with safeguards for responsible use

According to Anthropic, Claude Fable 5 is being introduced with additional safeguards that reflect the company’s approach to responsible AI development. Because the model has advanced capabilities in sensitive domains such as cybersecurity, biology, and chemistry, Anthropic has placed limits on how far the broadly available version will go in those areas. Beyond the model’s built-in safeguards, Microsoft Foundry provides developers with advanced guardrails and controls, as well as robust observability and security capabilities in Foundry Control Plane. Last week at Build, we announced guided guardrail setup, which walks developers through a few questions about an agent’s users, data, tools, and actions, then recommends and applies the right controls at the right intervention points, tailored to each agent’s scenario. These enterprise grade responsible AI features help developers govern, monitor, and manage AI systems and agent fleets.

For a small set of select users, including participants in Project Glasswing, Anthropic is also offering Claude Mythos 5. Mythos 5 is a version of the same model intended for internal, defensive use with those domain restrictions removed. This approach allows Anthropic to make most of Claude Fable 5’s frontier capabilities broadly available while continuing to refine safeguards for higher-risk use cases.

For enterprise customers, this means access to advanced autonomous capabilities with a clearer safety posture, which is an important consideration when deploying AI systems in real business environments.

Why Microsoft Foundry?

Access to a powerful model like Claude Fable 5 is only the starting point. The real challenge for enterprises is operationalizing autonomous AI securely, reliably, and in alignment with organizational policies.

As Jay Parikh, Executive Vice President of CoreAI at Microsoft, recently said:

The winners won’t be those with the most demos, but those that turn AI into a governed, continuously improving system for running real work.

That is why platform matters. Microsoft’s agent platform spanning GitHub, Microsoft IQ, Foundry, Agent 365, Azure, and Microsoft 365, gives organizations the foundation to build, ground, govern, and improve AI systems at scale.

Microsoft IQ plays a critical role by connecting agents to enterprise context across Microsoft 365, business systems, and knowledge bases, so models like Claude Fable 5 can reason with the right organizational context instead of operating in isolation.

With Microsoft Foundry, customers can turn frontier models into enterprise-ready solutions. They can evaluate and deploy Claude Fable 5 alongside other Claude models, apply platform-level security and governance controls, integrate AI into existing workflows, and scale from pilot to production with identity, access management, and operational controls built in.

Pricing

Model	Input/1M Tokens	Output/1M Tokens
Claude Fable 5	$10	$50

Moving from experimentation to impact

Claude Fable 5’s arrival on Microsoft Foundry marks a milestone for enterprises ready to tackle more ambitious problems, streamline complex workflows, and enhance productivity across the organization. By bringing Claude Fable 5 to Foundry, Azure enables organizations to move faster, from experimentation to real, accelerated business impact without compromising on trust or control.

Ready to explore what autonomous AI can do for your organization? Access Claude Fable 5 today in Foundry Models, Foundry Agent Service, and GitHub Copilot.