TLDR
- Anthropic launched Claude Fable 5 as a general-use Mythos-class model with cautious safety safeguards.
- The model’s coding strength may help DeFi teams review smart contracts and complex protocol systems.
- Security concerns remain because advanced AI can also assist vulnerability discovery by malicious actors.
- Claude Mythos 5 is limited to trusted cyber defenders and critical infrastructure providers through Project Glasswing.
- Anthropic priced Fable 5 and Mythos 5 at $10 input and $50 output per million tokens.
Anthropic has launched Claude Fable 5, a new Mythos-class model made available for general use with added safeguards. The company said the model exceeds its previous generally available systems across tested areas including software engineering, research, vision, knowledge work and long-context tasks.
The launch has drawn attention from security teams because stronger software and cybersecurity capabilities may affect how vulnerabilities are found in decentralized finance systems. Anthropic said some requests will be routed to Claude Opus 4.8 when safeguards detect topics that could carry misuse risk.
The company said the safeguards were intentionally tuned with caution, which may cause some harmless requests to be restricted. Anthropic said the system triggers in fewer than 5% of sessions on average, while future updates are expected to reduce false positives.
DeFi Security Concerns Enter Focus
The release places renewed attention on AI-driven smart contract review, protocol testing and vulnerability discovery in DeFi. Advanced models can help security researchers examine code, trace logic errors and identify weaknesses across complex blockchain applications.
At the same time, similar capabilities could raise concerns when used by malicious actors seeking flaws in lending platforms, bridges, decentralized exchanges, or wallet infrastructure. Anthropic said models at this capability level require stronger controls because cybersecurity features can be misused without restrictions.
The company is also launching Claude Mythos 5 for a limited group of cyber defenders and critical infrastructure providers through Project Glasswing. Mythos 5 uses the same underlying model as Fable 5 but has safeguards lifted in some areas for trusted users.
Stronger Coding and Research Abilities
Anthropic said Fable 5 can work across long tasks and large codebases with higher efficiency than earlier Claude models. During early testing, Stripe reportedly used the model for a large Ruby codebase migration that compressed work normally requiring a team over months into a much shorter period.
The company also cited performance in finance reasoning, scientific research, image understanding and long-context memory. Anthropic said Fable 5 can extract information from scientific figures, rebuild web applications from screenshots and remain focused across millions of tokens.
For DeFi developers, these abilities may support audits, monitoring tools and faster review of protocol upgrades. For regulators and security teams, the launch may also increase focus on access controls, model safeguards and responsible use of AI in financial technology.
Get 3 Free Stock Ebooks
Discover top-performing stocks in AI, Crypto, and Technology with expert analysis.
- Top 10 AI Stocks - Leading AI companies
- Top 10 Crypto Stocks - Blockchain leaders
- Top 10 Tech Stocks - Tech giants
