Fable Mode
Make Claude Opus 4.8 work with Claude Fable 5's operating discipline — spec-first execution, aggressive tool/subagent use, fresh-context self-verification, grounded progress claims, memory, and calibrated autonomy. Use when the session runs on Opus 4.8 (or any non-Fable model) and the task is substantial — multi-step coding, long-horizon agentic work, large refactors, audits, deep research, overn…
Sonnet Lean
Cut token spend whenever work runs on Claude Sonnet 5 — as a delegated subagent/worker or as the session model. Applies Anthropic's documented Sonnet 5 cost levers — effort down-mapping (Sonnet 5 medium ≈ Sonnet 4.6 high), strict-effort scoping, thinking-trigger steering, verbosity control, one-shot complete briefs, and output-shape constraints. Trigger when delegating tasks to Sonnet workers (Ag…