Claude Code, Skill
Webperf Snippets
Tested JavaScript snippets that measure and debug web performance.
Compatibility: Not stated.
Grade D
Two or more Medium findings, or a High. Only try it in a sandbox.
Not a guarantee. A hygiene check of the source at the commit shown, not a security audit.
INSTALL_LIFECYCLE_HOOK OBFUSCATION_MINIFIED_PAYLOAD
Why this grade
- INSTALL_LIFECYCLE_HOOK Medium
A package install hook (preinstall, install, postinstall or prepare) runs a script.
package.json, line 40
prepare - OBFUSCATION_MINIFIED_PAYLOAD Medium
Contains a very long line with almost no spaces in a script or style file.
package-lock.json, line 1
{
Any High, or two or more Medium findings, give D. One Medium gives C. Low findings or a security Note give B. Each code names a finding behind the letter.
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Grades are a hygiene check of the source at the commit shown, on the date checked, not a security audit or a guarantee. The free directory grades are automated. Before release, a PlugVet engineer reviews every paid report and any grade we hold back, including all F grades, against the source code and the evidence we quote.
What was checked
Plain notes from the hygiene checks.
Permissions
Concern
can delete files.
PERMISSION_DELETE_FILES
scripts/generate-skills.js, line 627
if (fs.existsSync(destPath)) fs.rmSync(destPath, { recursive: true, force: true })
scripts/install-from-release.js, line 118
if (fs.existsSync(dest)) fs.rmSync(dest, { recursive: true, force: true })
scripts/install-from-release.js, line 123
fs.rmSync(tmpDir, { recursive: true, force: true })
Show more
scripts/install-global.js, line 50
fs.rmSync(dest, { recursive: true, force: true })
scripts/install-skills.js, line 51
fs.rmSync(dest, { recursive: true, force: true })
scripts/prerendered-dir.test.js, line 18
fs.rmSync(dir, { recursive: true, force: true })
scripts/read-meta.test.js, line 15
fs.rmSync(dir, { recursive: true, force: true })
Install and update
Concern
runs a script at install time.
INSTALL_LIFECYCLE_HOOK
package.json, line 40
prepare
Network
Concern
can reach a host that is not written as a fixed address. can reach web.dev. The description does not name that host.
NETWORK_NO_FIXED_HOST NETWORK_UNNAMED_HOST
cli/src/crux.js, line 31
const res = await fetch(`${endpoint}?key=${encodeURIComponent(apiKey)}`, {
cli/src/report-to.js, line 33
const res = await fetch(url, {
components/WebMCP.js, line 8
registry: () => fetch('/webmcp/snippets.json').then((r) => r.json()),
Show more
components/WebMCP.js, line 9
markdown: (url) => fetch(new URL(url).pathname).then((r) => r.text()),
extension/panel.js, line 457
fetch('snippets.json')
scripts/ci-skip-slow-steps.js, line 47
const response = await fetch(url, {
scripts/install-from-release.js, line 37
https.get(url, options, (res) => {
scripts/install-from-release.js, line 60
https.get(url, options, (res) => {
Secrets
Concern
reads a credential or environment file.
SECRETS_ENV_READ SECRETS_PATH_DOTENV
cli/src/bin.js, line 180
const cruxKey = values["crux-key"] || process.env.CRUX_API_KEY;
cli/src/bin.js, line 197
apiKey: values["api-key"] || process.env.PERF_REVIEWS_API_KEY,
scripts/ci-skip-slow-steps.test.js, line 88
return main({ env: { ...env, GITHUB_OUTPUT: output, GITHUB_STEP_SUMMARY: summary }, fetchJson }).then(() => ({
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.gitignore, line 1
.env
scripts/smoke-cli-package.mjs, line 35
await client.connect(new StdioClientTransport({ command, args: ['mcp'], cwd: join(work, 'app'), env: { ...process.env, ...env } }))
Agent instructions
Pass
No instruction to ignore earlier instructions or to hide a step.
Obfuscation
Concern
contains a minified payload.
OBFUSCATION_MINIFIED_PAYLOAD
package-lock.json, line 1
{
public/llms-full.txt, line 1
# WebPerf Snippets - Full Reference
skills/webperf-core-web-vitals/scripts/INP.js, line 2
(()=>{if(!PerformanceObserver.supportedEntryTypes?.includes("event"))return{script:"INP",status:"unsupported",error:"event entries not supported in this browser"};let t=[],e=0,n=nu
Show more
skills/webperf-core-web-vitals/scripts/LCP-Image-Entropy.js, line 1
// snippets/CoreWebVitals/LCP-Image-Entropy.js | sha256:eeb1ce2de50a87b2 | https://github.com/nucliweb/webperf-snippets/blob/main/snippets/CoreWebVitals/LCP-Image-Entropy.js
Licence
Pass
A licence file is present (LICENSE).
Maintainer activity
Pass
The latest commit is within the last 365 days.
Note
Hygiene check of commit 59791d98627e. can delete files. runs a script at install time. can reach a host that is not written as a fixed address. can reach web.dev. The description does not name that host. reads a credential or environment file. contains a minified payload.
Date and source
Date checked:
github.com
Commit graded: 59791d98627eed9193d471b65edbecbfbabac704
This link goes to the original host. PlugVet does not host or check what you download from there, and installing it is your own decision and risk.