Link Validator

Validates markdown links in Claude Code skills for portability across installation locations.

Self-Evolving Skill: This skill improves through use. If instructions are wrong, parameters drifted, or a workaround was needed — fix this file immediately, don't defer. Only update for real, reproducible issues.

The Problem

Skills with absolute repo paths break when installed elsewhere:

Path Type	Example	Works When Installed?
Absolute repo	/skills/foo/SKILL.md	No - path doesn't exist
Relative	./references/guide.md	Yes - always resolves
Relative parent	../sibling/SKILL.md	Yes - always resolves

When to Use This Skill

• Before distributing a skill/plugin
• After creating new markdown links in skills
• When CI reports link validation failures
• To audit existing skills for portability issues

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TodoWrite Task Templates

Template A: Validate Single Skill

1. Identify skill path to validate
2. Run: uv run scripts/validate_links.py <skill-path>
3. Review violation report (if any)
4. For each violation, apply suggested fix
5. Re-run validator to confirm all fixed

Template B: Validate Plugin (Multiple Skills)

1. Identify plugin root directory
2. Run: uv run scripts/validate_links.py <plugin-path>
3. Review grouped violations by skill
4. Fix violations skill-by-skill
5. Re-validate entire plugin

Template C: Fix Violations

1. Read violation report output
2. Locate file and line number
3. Review suggested relative path
4. Apply fix using Edit tool
5. Re-run validator on file

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Post-Change Checklist

After modifying this skill:

1. Script remains in sync with latest patterns
2. References updated if new patterns added
3. Tested on real skill with violations

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Quick Start

# Validate a single skill
uv run scripts/validate_links.py ~/.claude/skills/my-skill/

# Validate a plugin with multiple skills
uv run scripts/validate_links.py ~/.claude/plugins/my-plugin/

# Dry-run in current directory
uv run scripts/validate_links.py .

Exit Codes

Code	Meaning
0	All links valid (relative paths)
1	Violations found (absolute repo paths)
2	Error (invalid path, no markdown files)

What Gets Checked

Flagged as Violations:

• /skills/foo/SKILL.md - Absolute repo path
• /docs/guide.md - Absolute repo path

Allowed (Pass):

• ./references/guide.md - Relative same directory
• ../sibling/SKILL.md - Relative parent
• https://example.com - External URL
• #section - Anchor link

Reference Documentation

• Link Patterns Reference - Detailed pattern explanations and fix strategies

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Troubleshooting

Issue	Cause	Solution
Script not found	Path or plugin not installed	Verify plugin installed with claude plugin list
Exit code 2	Invalid path or no .md files	Check target path exists and contains markdown
False positive on URL	Regex matched external link	URLs starting with http should be ignored
Anchor link flagged	Script treating # as path	Anchor links (#section) are allowed by design
Relative path still fails	Wrong relative direction	Use ./ for same dir, ../ for parent
Validation passes locally	CI uses different working dir	Ensure CI runs from correct repo root
Too many violations	Legacy codebase	Fix incrementally, prioritize high-impact files
Can't determine fix	Complex path structure	Read link-patterns.md for detailed fix strategies

Post-Execution Reflection

After this skill completes, check before closing:

1. Did the command succeed? — If not, fix the instruction or error table that caused the failure.
2. Did parameters or output change? — If the underlying tool's interface drifted, update Usage examples and Parameters table to match.
3. Was a workaround needed? — If you had to improvise (different flags, extra steps), update this SKILL.md so the next invocation doesn't need the same workaround.

Only update if the issue is real and reproducible — not speculative.