Claude Fable 5 model entry. Check the model plaza for the currently available model ID, then configure it through the Claude Code or external-tool setup guide that matches your client.
Anthropic officially introduced Claude Fable 5 on June 9, 2026 and describes it as a new generation of intelligence for the hardest knowledge work and coding problems. Anthropic says Fable 5 is a Mythos-class model built for longer, more complex, more asynchronous work, especially long-running agents, complex software engineering, knowledge work, and vision-heavy workflows.
Highlights
- Stronger long-running agent work: Anthropic says Fable 5 can operate for longer in Claude Code or an agent harness, planning across stages, executing, and checking its own work
- Better fit for complex software engineering: The model is positioned for large migrations, complex implementations, multi-day autonomous sessions, and engineering tasks that need less direct supervision
- Improved knowledge work and vision: Fable 5 targets complex analysis, document reasoning, charts, tables, PDFs, and other visual materials
- More active self-checking: Anthropic emphasizes that Fable 5 validates its own work more thoroughly, which helps when you hand off a task and review the result later
- New safeguards: For sensitive areas such as cybersecurity, biology, and chemistry, Anthropic applies safeguards and fallback behavior; some requests may be answered by Claude Opus 4.8 instead
Setup guidance
If you use Claude Code, start with the Claude Code setup guide. Different Key groups use different protocols and model configuration patterns:Claudegroup: usehttps://www.llmeasy.ruGPTgroup or external tools: follow the relevant tool guide withhttps://www.llmeasy.ru/v1
Claude Fable 5 is best for high-value, long-context, long-running tasks. For simple Q&A or low-cost batch work, choose a lighter model based on the groups and pricing shown in the model plaza.