Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add ncklrs/claude-chrome-user-testing --skill link-checkergit clone --depth 1 https://github.com/ncklrs/claude-chrome-user-testingWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/ncklrs/claude-chrome-user-testing/link-checker)<a href="https://agentmods.dev/skills/ncklrs/claude-chrome-user-testing/link-checker"><img src="https://agentmods.dev/badge/skills/ncklrs/claude-chrome-user-testing/link-checker/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/ncklrs/claude-chrome-user-testing/link-checker"><img src="https://agentmods.dev/badge/skills/ncklrs/claude-chrome-user-testing/link-checker.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00000 | $0.01540 |
| Opus 5 | $0.00000 | $0.00770 |
| Sonnet 5 | $0.00000 | $0.00308 |
| Haiku 4.5 | $0.00000 | $0.00154 |
Grade A, and why
link-checker scanned grade A with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 9d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
const response = await fetch(currentUrl, { How it starts
The opening of the file, as written. The whole thing — 247 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Link Checker Skill
Find and validate links on web pages. Reports broken links, redirects, and other issues.
When to Use
- Before releases to catch broken links
- After content updates
- During user testing (with
--check-linksflag) - Regular site maintenance
Link Extraction
Using Browser Snapshot
Use browser_snapshot to get page accessibility tree, then extract links:
// Links to extract
const linkSelectors = [
'a[href]', // Standard links
'area[href]', // Image map links
'link[href]', // Stylesheet/resource links (optional)
];
Link Types to Identify
| Type | Pattern | Action |
|---|---|---|
| Internal | Same domain | Check via HEAD |
| External | Different domain | Check via HEAD (unless excluded) |
| Anchor | #section |
Verify element exists |
| mailto: | mailto:* |
Validate format |
| tel: | tel:* |
Validate format |
| javascript: | javascript:* |
Flag as warning |
| data: | data:* |
Skip |
Extracting via browser_evaluate
async (page) => {
const links = await page.evaluate(() => {
const anchors = document.querySelectorAll('a[href]');
return Array.from(anchors).map(a => ({
href: a.href,
text: a.textContent.trim().slice(0, 50),
location: a.closest('[id]')?.id || 'page'
}));
});
return links;
}
Link Validation
HEAD Request Method
For each link, make a HEAD request to check status:
async (page) => {
const response = await page.request.head(url, {
timeout: 10000,
ignoreHTTPSErrors: false
});
return {
status: response.status(),
headers: response.headers()
};
}
Status Interpretation
| Status Code | Category | Action |
|---|---|---|
| 200 | Success | Mark as working |
| 201-299 | Success | Mark as working |
| 301 | Permanent Redirect | Warn - update link |
| 302 | Temporary Redirect | Note redirect |
| 303, 307, 308 | Redirects | Note redirect |
| 400 | Bad Request | Error |
| 401, 403 | Auth Required | Warning |
| 404 | Not Found | Error - broken link |
| 405 | Method Not Allowed | Retry with GET |
| 429 | Rate Limited | Wait and retry |
| 500-599 | Server Error | Error |
| Timeout | No Response | Error |
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 9d ago First seen · 247 lines · 0 tokens per session scan A fd8a2afa6e63
link-checker is a skill published in the GitHub repository ncklrs/claude-chrome-user-testing (19 stars, last pushed 8mo ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 1,540 tokens. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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