Extended Thinking

Q: What is a Claude Code skill and how does the Extended Thinking skill fit in?

A Claude Code skill is a SKILL.md file that lives under ~/.claude/skills/<name>/ and tells the Claude Code CLI agent how to perform a specific task (instructions, prompts, allowed tools). Skills are auto-discovered at session start. Extended Thinking is one of 67,000+ skills indexed in the open ClaudSkills catalog, classified under the General category. Learn more at https://claudskills.com/learn/what-is-skill-md/.

Category: General · Sub-category: general-misc · Last updated: 2026-05-21

Extended thinking (ultrathink) configuration for Claude API. Activate for complex reasoning tasks, deep analysis, multi-step problem solving, and tasks requiring careful deliberation. Enables Claude's internal reasoning with configurable thinking budgets.

About this skill (catalog notes)

Extended Thinking includes 6 code blocks for direct copy-paste. The SKILL.md runs to about 707 words, in the catalog's typical mid-range.

Indexed lastmod: 2026-05-21
Catalog position: General · general-misc
Indexed related skills: 10

How Extended Thinking fits the catalog

Extended Thinking sits in the General category under the general-misc sub-topic in the ClaudSkills catalog. There are 10 related skills indexed alongside it; comparing a few before installing usually reveals which fits your workflow best.

These notes are auto-generated from features detected in the SKILL.md file and from this catalog's structure — they aren't part of the source repository.

From the source SKILL.md

Enable Claude's extended thinking capabilities for complex reasoning tasks that benefit from internal deliberation before responding.

What this skill does

Extended Thinking is a community-contributed Claude Code skill in the general-misc sub-category. It ships as a SKILL.md file that Claude Code auto-discovers under ~/.claude/skills/extended-thinking/ and loads when your prompt matches the skill's trigger.

Who uses this skill

The Extended Thinking Claude Code skill is built for Claude Code users and developers across all disciplines looking for general-purpose AI assistance. It's part of ClaudSkills (also referred to as Claude Skills or Claude Code Skills) — the open community-curated registry of 116,000+ SKILL.md files for Anthropic's Claude Code agent and the wider Claude ecosystem (Claude API, Claude Agent SDK).

How to install

Free

Manual install (2 steps)

mkdir -p ~/.claude/skills/extended-thinking
curl -L https://claudskills.com/skills/extended-thinking/SKILL.md \
  -o ~/.claude/skills/extended-thinking/SKILL.md

Or just download SKILL.md directly and drop it into ~/.claude/skills/extended-thinking/. Claude Code auto-discovers it on next session.

Skills live at ~/.claude/skills/extended-thinking/SKILL.md on macOS/Linux, or %USERPROFILE%\.claude\skills\extended-thinking\SKILL.md on Windows. See the full install guide for step-by-step instructions.

📱 Install from your phone or desktop Telegram

Open @claudskills_bot on Telegram, tap Open Desktop App, and the desktop app installs this skill for you. Or share the bot link with a colleague — they get the same one-tap install. Learn more →

Pro

One-click install via the desktop app

The ClaudSkills desktop app installs any skill directly into ~/.claude/skills/ with one click — no terminal required. Pro starts at $9/mo or $149 lifetime.

Pro

For the full experience including quality scoring and one-click install features for each skill — upgrade to Pro.

See pricing → Download desktop app

Frequently asked questions

How do I install the Extended Thinking Claude Code skill?

Install via the ClaudSkills desktop app (one click) or copy SKILL.md from the source repository to ~/.claude/skills/extended-thinking/SKILL.md and restart Claude Code. Both flows are detailed at claudskills.com/install/.

What does the Extended Thinking skill do?

Is this skill free to install?

Yes. ClaudSkills is an open registry — every skill keeps its source repository's license, and manual install via copy is free. ClaudSkills Pro ($9/mo, $79/yr, or $149 one-time) adds one-click install via the desktop app and a multi-signal Quality Score.

When should I use the Extended Thinking skill?

Use Extended Thinking when your Claude Code task falls under the General category — specifically in the general misc area. Claude Code auto-discovers installed skills and invokes the right one based on the task description, so you can also ask Claude directly (e.g. "use Extended Thinking" or describe the task and let Claude pick). Browse related skills at /category/general/.

What is a Claude Code skill and how does the Extended Thinking skill fit in?

A Claude Code skill is a SKILL.md file that lives under ~/.claude/skills/<name>/ and tells the Claude Code CLI agent how to perform a specific task (instructions, prompts, allowed tools). Skills are auto-discovered at session start. Extended Thinking is one of 67,000+ skills indexed in the open ClaudSkills catalog, classified under the General category. Learn more at /learn/what-is-a-claude-skill/.

Cite this skill

If you reference this skill in a blog post, paper, or documentation, you can cite it as:

APA

ClaudSkills. (2026). Extended Thinking [Claude Code skill]. ClaudSkills. https://claudskills.com/skills/extended-thinking/

BibTeX

@misc{extended-thinking-2026,
  author    = {ClaudSkills},
  title     = {Extended Thinking [Claude Code skill]},
  year      = {2026},
  publisher = {ClaudSkills},
  url       = {https://claudskills.com/skills/extended-thinking/}
}

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Badge

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Part of ClaudSkills — the open registry for Claude Skills & Claude Code Skills. · What's New · Install guide · About · llms.txt

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