ui-verification

ui-verification is a skill for Claude Code from mblode/agent-skills. It costs 74 tokens per session (3,131 once invoked), scanned A, original, MIT.

A browser-based UI verification skill that loads an application and measures how it behaves at runtime. It checks areas such as keyboard focus, clickable target size, overflow, themes, request failures, layout movement, and accessibility scans.

In plain words
What is it for?
Use it to reproduce or dismiss UI findings, collect evidence linked to rule IDs, and rerun checks after a fix.
Why use it?
Reading source code can miss problems that only appear in a running page; browser checks provide reproducible observations and measurements.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the agent-skills plugin — 26 skills shipped together

Good fit Use it to reproduce or dismiss UI findings, collect evidence linked to rule IDs, and rerun checks after a fix.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/mblode/agent-skills/ui-verification
Install

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.

agentmods
npx agentmods add skills/mblode/agent-skills/ui-verification
Any agent
npx skills add mblode/agent-skills --skill ui-verification
Clone the repo
git clone --depth 1 https://github.com/mblode/agent-skills

Made for: Claude Code.

Or install agent-skills, the plugin that ships this one along with the rest of its 26 skills.

Wrote 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.

agentmods badge for ui-verification

README.md
[![agentmods](https://agentmods.dev/badge/skills/mblode/agent-skills/ui-verification.svg)](https://agentmods.dev/skills/mblode/agent-skills/ui-verification)
Your own site
<a href="https://agentmods.dev/skills/mblode/agent-skills/ui-verification"><img src="https://agentmods.dev/badge/skills/mblode/agent-skills/ui-verification.svg" alt="Measured on agentmods" height="20"></a>
Per session 74 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,131 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00074 $0.03131
Opus 5 $0.00037 $0.01566
Sonnet 5 $0.00015 $0.00626
Haiku 4.5 $0.00007 $0.00313

Measured yesterday against content hash 435438f0f616, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

ui-verification scanned grade A with 0 findings 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 yesterday.

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.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/ui-verification/SKILL.md · 153 lines

How it starts

The opening of the file, as written. The whole thing — 153 lines — stays where its author put it; the contents beside it link to each section on GitHub.

UI Verification

Owns the browser session. Every other UI skill in this repo reasons about source and infers what the user will see; this one loads the page and measures it.

  • IS: booting the app, driving it with a browser, and running the probes that decide a rule at runtime: computed boxes, injected failures, observed layout shift, a scripted Tab walk, an axe scan per theme. Output is findings keyed to rule ids with reproducible evidence, plus the clearing re-run after a fix.
  • IS NOT: finding defects by reading source or deciding their tier and ship verdict (ui-design Audit mode owns both); building or restyling UI (ui-design Build); authoring a durable test suite (write Playwright tests); pixel-diff regression against a baseline (Chromatic, Percy); field performance (RUM or CrUX; Lighthouse is a lab tool).

The division of labour is the point. A static audit reports what the code will probably do; it cannot see a 40px control whose hit area a pseudo-element already expands to 44, or a retry button wired to nothing. This skill reproduces or kills each of those, so a finding arrives with a measurement instead of a confidence.

Contents

When to run

Situation What this skill does
A ui-design audit emitted findings and the user wants them confirmed Run only the probes those rule ids map to, in references/rule-coverage.md
No audit ran; the user points at a route or a running app Detect features, run the full battery on the resolved routes
A fix just landed for a previously reproduced finding Run the clearing re-run only (step 5)
The user asks for captures across themes or widths probes/theme-locale-matrix.md alone
A design-system.md claims a scale and someone needs it checked Read the claimed values off computed styles on a real page; a theme value the build overrides never reaches the browser

Read the full file on GitHub · 153 lines

Changes

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.

  1. yesterday First seen · 153 lines · 74 tokens per session scan A 435438f0f616

Subscribe to this mod's changes

ui-verification is a skill published in the GitHub repository mblode/agent-skills (103 stars, last pushed yesterday), licensed MIT. It adds 74 tokens to every session and 3,131 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-05.