Txt Undo

Q: What is a Claude Code skill and how does the Txt Undo 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. Txt Undo is one of 67,000+ skills indexed in the open ClaudSkills catalog, classified under the Content category. Learn more at https://claudskills.com/learn/what-is-skill-md/.

Category: Content · Sub-category: content-misc · Last updated: 2026-05-21

Implement and debug undo and redo in text editors — NSUndoManager grouping with beginUndoGrouping/endUndoGrouping, automatic typing coalescing on UITextView and NSTextView, disabling registration around programmatic edits, the changeInLength bug that breaks undo on custom NSTextStorage subclasses, registering manual inverses on NSTextContentManager, and avoiding cross-talk with Writing Tools revert. Trigger on 'undo isn't working right', 'too many undo steps for one paste', 'undo lost my work after Writing Tools', 'cmd-z behaves wrong' even without NSUndoManager named. Use when undo collapses too many changesUse when undo collapses too many changes, splits one operation into many groups, applies wrong inverse ranges, or stops working entirely after a paste, replace-all, or document load.

From the source SKILL.md

Authored against iOS 26.x / Swift 6.x / Xcode 26.x.

What this skill does

Txt Undo is a community-contributed Claude Code skill in the content-misc sub-category. It ships as a SKILL.md file that Claude Code auto-discovers under ~/.claude/skills/txt-undo/ and loads when your prompt matches the skill's trigger.

When to invoke it: Use when undo collapses too many changesUse when undo collapses too many changes, splits one operation into many groups, applies wrong inverse ranges, or stops working entirely after a paste, replace-all, or document load.

Who uses this skill

The Txt Undo Claude Code skill is built for content creators, marketers, copywriters, SEO professionals, and editorial teams. 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/txt-undo
curl -L https://claudskills.com/skills/txt-undo/SKILL.md \
  -o ~/.claude/skills/txt-undo/SKILL.md

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

Skills live at ~/.claude/skills/txt-undo/SKILL.md on macOS/Linux, or %USERPROFILE%\.claude\skills\txt-undo\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 Txt Undo Claude Code skill?

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

What does the Txt Undo 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 Txt Undo skill?

Use Txt Undo when your Claude Code task falls under the Content category — specifically in the content 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 Txt Undo" or describe the task and let Claude pick). Browse related skills at /category/content/.

What is a Claude Code skill and how does the Txt Undo 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. Txt Undo is one of 67,000+ skills indexed in the open ClaudSkills catalog, classified under the Content category. Learn more at /learn/what-is-a-claude-skill/.

Attribution & license

License: MIT

Cite this skill

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

APA

ClaudSkills. (2026). Txt Undo [Claude Code skill]. ClaudSkills. https://claudskills.com/skills/txt-undo/

BibTeX

@misc{txt-undo-2026,
  author    = {ClaudSkills},
  title     = {Txt Undo [Claude Code skill]},
  year      = {2026},
  publisher = {ClaudSkills},
  url       = {https://claudskills.com/skills/txt-undo/}
}

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