High-tier autonomy comes with steep costs: Fable 5 is priced at $10/$50 per 1M tokens, with some teams burning $1,500 in just 10 hours. It supports nested sub-agents up to 5 levels deep for complex planning.
@jerryjliu0 @openclaw_lab
Anthropic has rolled out Claude Fable 5, and Claude Code instantly got more interesting 🎉
Anthropic released Claude Fable 5 - a new public Mythos-class model for complex development, long-running tasks, and agentic workflows.
The model is already available in many places. Anthropic specifically notes that Fable 5 shines on longer tasks: planning, staged execution, self-checking, and delegating subtasks.
At the same time, Claude Code has started rolling out an important update: nested subagents. Now an agent can launch subagents, and those subagents can launch their own subagents. The initial limit is up to 5 levels of nesting.
The main agent no longer has to carry the entire project, all logs, file search, tests, and review in one context. It can distribute the work across separate agents: one explores the codebase, another prepares the change, a third runs tests, a fourth reviews the diff, and a fifth looks for risks. Each returns a short result, and the main agent assembles the final solution.
Boris Cherny from the Claude Code team shared an example in the comments: a skill can run in a separate context, and inside that skill you can ask agents to keep each step isolated. This approach is already being added to /code-review, so reviews clutter the main context less and work more accurately.