The whole hunk
from line 212, old and new numbered
/
lines
from line 212
212212*Fable* is the most
213213capable model for your hardest, longest-running tasks; it is not the
214214default, so select it with `/model fable`, and note that cybersecurity and
215biology content falls back to Opus automatically. Opus 5 runs its own
216checks, so flagged cybersecurity content switches models and flagged
217biology content is refused.
215biology content falls back to Opus automatically. Opus 5.5 and Opus 5 run
216their own checks too: flagged content switches to an earlier Opus, except
217that flagged biology content on Opus 5 is refused.
218218
219219*Try it now:* type `/model` and pick Sonnet if you haven't already. It is
220220the right default for most tasks.
from line 222
222222📖 Model configuration → https://code.claude.com/docs/en/model-config
223223```
224224
225| Model | Best for |
226| ------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
227| Fable | The hardest, longest-running tasks. Opt-in only: select it with `/model fable`. Cybersecurity or biology content triggers [automatic model fallback to Opus](/docs/en/model-config#automatic-model-fallback) |
228| Opus | Large-scale refactors, complex debugging, architecture decisions, high-stakes changes. On Opus 5, cybersecurity or biology content triggers [automatic model fallback or a refusal](/docs/en/model-config#automatic-model-fallback) |
229| Sonnet | Everyday feature work, bug fixes, tests, documentation, code review. Recommended default. |
230| Haiku | Quick questions, formatting, mechanical edits, rapid iteration |
225| Model | Best for |
226| ------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
227| Fable | The hardest, longest-running tasks. Opt-in only: select it with `/model fable`. Cybersecurity or biology content triggers [automatic model fallback to Opus](/docs/en/model-config#automatic-model-fallback) |
228| Opus | Large-scale refactors, complex debugging, architecture decisions, high-stakes changes. On Opus 5.5 and Opus 5, cybersecurity or biology content triggers [automatic model fallback or a refusal](/docs/en/model-config#automatic-model-fallback) |
229| Sonnet | Everyday feature work, bug fixes, tests, documentation, code review. Recommended default. |
230| Haiku | Quick questions, formatting, mechanical edits, rapid iteration |
231231
232232**Quick wins to try first**
233233