webapp-testing

A browser-based check of a locally running web app. It follows the app's visible state and records whether a user flow really works.

In plain words
What is it for?
Use it to start an app, inspect its page and browser activity, perform actions using observed elements, and collect pass-or-fail evidence.
Why use it?
It catches problems that unit tests can miss, such as broken pages, browser errors, failed network requests, or selectors that no longer match.

Skill for Claude CodeCodex

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/hmbown/codewhale/webapp-testing
Any agent
npx skills add Hmbown/CodeWhale --skill webapp-testing
Clone the repo
git clone --depth 1 https://github.com/Hmbown/CodeWhale

Made for: Claude Code, Codex.

Per session 32 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 139 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 $0.00032 $0.00139
Opus 5 $0.00016 $0.00069
Sonnet 5 $0.00006 $0.00028
Haiku 4.5 $0.00003 $0.00014

Measured yesterday against content hash 54a739f8bcdc, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

webapp-testing 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.

crates/tui/assets/skills/webapp-testing/SKILL.md · 22 lines

What it actually says

Webapp Testing

When to use

Use to prove a web app flow works in a real browser/runtime context.

Non-goals

  • Do not claim success from unit tests alone.
  • Do not hardcode fragile selectors without observation.

Workflow

  1. Start or reuse the local app.
  2. Wait for readiness.
  3. Inspect DOM/console/network.
  4. Drive the flow from observed state.
  5. Record evidence of pass/fail.
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 · 22 lines · 32 tokens per session scan A 54a739f8bcdc

Subscribe to this mod's changes

webapp-testing is a skill published in the GitHub repository Hmbown/CodeWhale (40,867 stars, last pushed yesterday), licensed MIT. It adds 32 tokens to every session and 139 once invoked, about $0.0002 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 2026-08-30.

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