verify-frontend-change

verify-frontend-change is a skill for Claude Code, Codex from vscarpenter/gsd-task-manager. It costs 0 tokens per session (2,335 once invoked), scanned A, original, MIT.

A browser-based verification process for frontend changes, meaning changes to the part of an app that users see and interact with.

In plain words
What is it for?
Use it to check the running app after UI changes, observe real behavior, record a pass-or-fail result, and add a Playwright browser test for behavior worth keeping.
Why use it?
It catches stale cached files, missing sample data, console errors, and network problems that can make an apparently successful test misleading.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: mentions subagents; installed under .agents/ (shared by several agents).

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/vscarpenter/gsd-task-manager/skill-snapshot
Any agent
npx skills add vscarpenter/gsd-task-manager --skill skill-snapshot
Clone the repo
git clone --depth 1 https://github.com/vscarpenter/gsd-task-manager

Made for: Claude Code, Codex.

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 verify-frontend-change

README.md
[![agentmods](https://agentmods.dev/badge/skills/vscarpenter/gsd-task-manager/skill-snapshot.svg)](https://agentmods.dev/skills/vscarpenter/gsd-task-manager/skill-snapshot)
Your own site
<a href="https://agentmods.dev/skills/vscarpenter/gsd-task-manager/skill-snapshot"><img src="https://agentmods.dev/badge/skills/vscarpenter/gsd-task-manager/skill-snapshot.svg" alt="Measured on agentmods" height="20"></a>
Per session 0 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,335 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 $0.00000 $0.02335
Opus 5 $0.00000 $0.01167
Sonnet 5 $0.00000 $0.00467
Haiku 4.5 $0.00000 $0.00233

Measured 6d ago against content hash a47300bc048a, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-05, from the pricing page.

Security

Grade A, and why

verify-frontend-change 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 6d ago.

The scan reads SKILL.md. This mod also ships 2 executable files (scripts/reset-app-state.js, scripts/seed-tasks.js), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

.agents/skills/verify-frontend-change-workspace/skill-snapshot/SKILL.md · 134 lines

How it starts

The opening of the file, as written. The whole thing — 134 lines — stays where its author put it; the contents beside it link to each section on GitHub.

verify-frontend-change

Confirm a frontend change does what it's supposed to in the running app, not just in your head. The output is a PASS/FAIL verdict backed by evidence — never a confident guess.

This skill exists because two traps in this codebase silently turn verification into theater:

  1. The service worker serves stale JS chunks. You edit border-l-4border, reload, and still see the old UI. Your screenshot "confirms" code that isn't running.
  2. Data surfaces render empty on a fresh load. The dashboard and matrix have nothing to show until tasks exist. A screenshot of an empty dashboard "confirms" a layout you never actually saw.

Either trap produces a false PASS — the most dangerous outcome, because it ends the investigation with the wrong answer. Everything below is built to make PASS mean something.

When to use

Use this after editing any .tsx/.jsx under components/ or app/, or any change that affects what the user sees or does — the matrix, capture bar, edit drawer, dashboard, settings, task cards. Reach for it before pushing or opening a PR on UI work.

Don't use it for backend/sync-only logic (lib/sync/**), pure data transforms with unit-test coverage, or styling-only token tweaks already covered by inkwell-retrofit — those have better-fit verification.

Default dimensions

Verify these two by default — they catch the most regressions per unit of effort:

  • Functional behavior — does the change do what the acceptance criteria say? The "did it actually work" check.
  • Console & network errors — runtime errors, failed requests, and React warnings a screenshot can't show.

Accessibility and visual/Inkwell fidelity are opt-in escalations (see below), not part of every run. Add them when the change is a11y-sensitive (new interactive element, focus flow) or visually significant (new layout, color, spacing) — or when asked.

The flow

1. Scope the change

Identify which surface(s) changed and what "correct" means. Pull the acceptance criteria from the task/spec/PR if they exist; if they don't, state in one line what behavior you're about to confirm. Pick the verification altitude — a one-line copy fix needs a glance; a new interaction needs the full loop.

Read the full file on GitHub · 134 lines

Files

What ships with it

3 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 6d ago First seen · 134 lines · 0 tokens per session scan A a47300bc048a

Subscribe to this mod's changes

verify-frontend-change is a skill published in the GitHub repository vscarpenter/gsd-task-manager (25 stars, last pushed yesterday), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 2,335 tokens. 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 2026-08-30.

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