A browser-testing specialist that checks a website by using it like a real visitor, including on a narrow mobile screen. It tests normal actions as well as invalid, empty, and unusual inputs.

Testing websites with Playwright, an automated browser tool, across successful and failing scenarios. It also reports whether the work is ready based on passed and failed tests.

It helps find broken user flows and edge cases before users do. Each result records the steps, expected behavior, and what actually happened.

How Yasuui/ystack configures Claude Code and Gemini CLI

Reuse

Borrowing it

Nothing to install: this file belongs to Yasuui/ystack. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/Yasuui/ystack/main/.gemini/agents/qa.md

Clone the repo

git clone --depth 1 https://github.com/Yasuui/ystack

Made for: Claude Code, Gemini CLI.

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.

README.md

[![agentmods](https://agentmods.dev/badge/agents/yasuui/ystack/qa/github.svg)](https://agentmods.dev/agents/yasuui/ystack/qa)

Your own site

<a href="https://agentmods.dev/agents/yasuui/ystack/qa"><img src="https://agentmods.dev/badge/agents/yasuui/ystack/qa/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/agents/yasuui/ystack/qa"><img src="https://agentmods.dev/badge/agents/yasuui/ystack/qa.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 28 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.

When invoked 144 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

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.

Model	Per session	Once invoked
Fable 5.1	$0.00028	$0.00144
Opus 5.5	$0.00011	$0.00058
Sonnet 5.5	$0.00006	$0.00029
Haiku 4.5	$0.00003	$0.00014

Measured 2mo ago against content hash 47d205781132, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

ystack_qa 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 2mo ago.

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.

.gemini/agents/qa.md · 13 lines

What it actually says

You are the ystack QA Agent. Test to break, not to pass.

Cover: happy path, sad paths (empty, invalid, too long), edge cases, mobile 375px. Per test: [PASS/FAIL] name | Steps | Expected | Actual.

Write to .agents/brain/qa-output.md. End with: X passed, X failed — STATUS: READY or NOT READY — [reason]

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.

2mo ago First seen · 13 lines · 28 tokens per session scan A 47d205781132

Subscribe to this mod's changes

ystack_qa is an agent published in the GitHub repository Yasuui/ystack (1 stars, last pushed 1mo ago), licensed MIT. It adds 28 tokens to every session and 144 once invoked, about $0.0001 per session on Opus 5.5. 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 2026-08-31.

E2E testing Testing ai-tools antigravity developer-tools gemini-cli mcp open-source

ystack_qa next to 6 agents from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
ystack_qaYasuui/ystack	Agent	1	1mo ago	MIT	A	28	Claude Code, Gemini CLI
e2e-runnerJamkris/everything-gemini-code	Agent	93	5mo ago	MIT	A	69	Claude Code
gan-evaluatorJamkris/everything-gemini-code	Agent	93	5mo ago	MIT	A	32	Claude Code
test-generatortravisjneuman/.claude	Agent	107	yesterday	MIT	A	27	Claude Code
quality-guardianroedyrustam/vibes-plug	Agent	121	yesterday	MIT	A	55	Claude Code, Cursor
test-engineervinvcn/addyosmani-agent-skills-zh	Agent	46	17d ago	MIT	A	39	Claude Code
qa-engineerulises-jeremias/agent-toolkit	Agent	19	today	MIT	A	66	Claude Code

ystack: Agent for Claude Code