web-perf SKILL.md skillA
web-perf from vanducng/skills is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add vanducng/skills/web-perf@v0.1.0Pins v0.1.0 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- vanducng/skills
- Path
skills/web-perf/SKILL.md- Versions recorded
- 4
- Latest version
- v0.1.0, committed Aug 16, 2026
- First version recorded
- Jun 12, 2026
- Size
- 5,811 bytes
- Repository stars
- 8
- License
- MIT
Measure Core Web Vitals (LCP, CLS, INP, FCP, TTFB), JS heap, and record DevTools performance traces against a running Chrome - attaches to vd:browser-profile's deterministic CDP ports, no Puppeteer, no separate browser. Use when the user says "why is this page slow", "measure web vitals", "check LCP/CLS/INP", "record a performance trace", "profile page load", or wants performance evidence in an e2e run.
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# web-perf Performance measurement that attaches to the browser you already have. `vd:browser-trace` is a read-only observer - it never sends CDP commands, so it can't compute vitals or drive Chrome's tracer. This skill is the *active* counterpart: two stdlib Node scripts that connect to a CDP port (a `vd:browser-profile` profile's deterministic port, or any `--remote-debugging-port` Chrome), evaluate buffered `PerformanceObserver`s in-page, and stream a DevTools-loadable `trace.json` out. No Puppeteer, no bundled Chromium, no node_modules - measuring against the persistent profile means vitals reflect the *logged-in* app surface (authed dashboards, not marketing pages), with warm-cache caveats noted below. ## What this skill is - and isn't | Skill | Role | |---|---| | `vd:browser-trace` | Passive evidence: network/console/screenshots, never interferes | | `vd:web-perf` (this) | Active measurement: vitals, heap, Chrome tracing - sends CDP commands | | `vd:agent-browser` | Driving: navigate/click/fill - pair it to create the interactions INP needs | **Not for:** load testing (k6 territory), Lighthouse-style audits/scores, or production RUM. ## Quick start ```bash …
Read the whole file at its exact version.
How to install
mdr add vanducng/skills/web-perf@sha256:d0466e0f4ffd46c2The line at the top of this page pins the label v0.1.0, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_cnlnpha4gph4c26v)
3 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 4 versions of this file, between Jun 12, 2026 and Aug 16, 2026, about one every 22 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| v0.1.0 latest | 2026-08-16 | c83d21b | 5,811 B | A | view · diff |
| v0.1.0 | 2026-07-24 | 51405ee | 5,799 B | A | view · diff |
| v0.1.0 | 2026-07-10 | 6f1e7cf | 5,825 B | A | view · diff |
| v0.1.0 | 2026-06-12 | 68fc8f7 | 5,538 B | A | view |
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (5811 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
vanducng/skills · 8 stars · license MIT · pushed 2026-11-05 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_cnlnpha4gph4c26v GET https://markdownregistry.com/api/v1/resolve?ref=vanducng/skills/web-perf GET https://markdownregistry.com/api/v1/blob/d0466e0f4ffd46c24dd487e885f1b415caace82a07ca6d8bbad94bb66d65e5b7
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.