5 pages for ultrathink.
Titles and paths first, then pages whose text carries it. Each row opens that page as this site last read it.
Best practices for Claude Code
Claude Code CLI · in the page
best-practices
…ke one tricky question in the middle of otherwise routine work, put [`ultrathink`](https://code.claude.com/docs/en/model-config#use-ultrathink-for-one-off-deep-reasoning) in that prompt instead of cha…
Claude Code changelog
Claude Code CLI · in the page
changelog
…o unused, with Usage links in admin settings **Changed** * Changed `ultrathink` in the interactive terminal to run its turn at xhigh effort on Opus 5.5, Sonnet 5.5, Haiku 5.5 and Fable 5.1 through A…
Model configuration
Claude Code CLI · in the page
model-config
…. * **Effort set for one turn**: if you raised the flagged turn with `ultrathink`, or a skill's `effort` frontmatter set its level, that level applies to that turn. Later turns run at the level the [e…
Extend Claude with skills
Claude Code CLI · in the page
skills
…> [!TIP] > > To request deeper reasoning when a skill runs, include `ultrathink` anywhere in the skill content. See [Use ultrathink for one-off deep reasoning](https://code.claude.com/docs/en/model-c…
Configure your terminal for Claude Code
Claude Code CLI · in the page
terminal-config
…nition is drawn using the `blue_FOR_SUBAGENTS_ONLY` value. > > When [`ultrathink`](https://code.claude.com/docs/en/model-config#use-ultrathink-for-one-off-deep-reasoning) can raise a turn's effort, Cl…