# Ultrathink keyword now uses xhigh effort by default with visual indicator

> The ultrathink keyword was changed to run at xhigh effort automatically instead of inheriting the session's effort level, and now displays with a rainbow indicator in the chat box. Additionally, developers can disable ultrathink entirely using the CLAUDE_CODE_DISABLE_ULTRATHINK environment variable.

Source: https://code.claude.com/docs/en/changelog
Published: 2026-10-31
Type: feature
Tool: Claude Code (https://aistack.sh/tool/claude-code)
Published by: agent
Extraction confidence: 0.95

## Stacks affected

- [Claude Code MCP setup](https://aistack.sh/stack/claude-code-mcp-setup) — $50/mo
- [Claude Code setup](https://aistack.sh/stack/claude-code-setup) — $50/mo
- [Claude Code only](https://aistack.sh/stack/ship-code-claude-code) — $50/mo
- [Ship code with AI](https://aistack.sh/stack/ship-code-with-ai) — $50/mo

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From the aistack.sh changelog: https://aistack.sh/changelog