qa-engineer

qa-engineer is an agent for Claude Code from The-AI-Directory-Company/agents-and-skills. It costs 61 tokens per session (1,722 once invoked), scanned A, original, MIT.

A hands-on quality-assurance agent that tests software by exploring it, checking edge cases, and running regression tests. Regression testing checks that existing features still work after changes.

In plain words
What is it for?
Use it to execute tests, explore features, check regressions, investigate edge cases, and manage test environments.
Why use it?
It looks for problems that automated test suites may not cover, especially in unusual user actions, error states, and differences between test and production environments.

Agent for Claude Code

Written for Claude Code: a Claude Code subagent (agents/*.md).

Good fit Use it to execute tests, explore features, check regressions, investigate edge cases, and manage test environments.

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Install with agentmods
npx agentmods add agents/the-ai-directory-company/agents-and-skills/qa-engineer
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.

Clone the repo
git clone --depth 1 https://github.com/The-AI-Directory-Company/agents-and-skills

Made for: Claude Code.

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 qa-engineer

README.md
[![agentmods](https://agentmods.dev/badge/agents/the-ai-directory-company/agents-and-skills/qa-engineer/github.svg)](https://agentmods.dev/agents/the-ai-directory-company/agents-and-skills/qa-engineer)
Your own site
<a href="https://agentmods.dev/agents/the-ai-directory-company/agents-and-skills/qa-engineer"><img src="https://agentmods.dev/badge/agents/the-ai-directory-company/agents-and-skills/qa-engineer/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.

agentmods 80×15 button for qa-engineer

Your own site · 80×15
<a href="https://agentmods.dev/agents/the-ai-directory-company/agents-and-skills/qa-engineer"><img src="https://agentmods.dev/badge/agents/the-ai-directory-company/agents-and-skills/qa-engineer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 61 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,722 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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00061 $0.01722
Opus 5 $0.00030 $0.00861
Sonnet 5 $0.00012 $0.00344
Haiku 4.5 $0.00006 $0.00172

Measured 8d ago against content hash 233c60b247c0, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

qa-engineer 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 8d 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.

agents/qa-engineer.md · 71 lines

How it starts

The opening of the file, as written. The whole thing — 71 lines — stays where its author put it; the contents beside it link to each section on GitHub.

QA Engineer

You are a senior QA engineer who has found the bugs that slipped past three rounds of code review and full test suites. You have broken features that "definitely work" within minutes of touching them, because you think like a user who makes mistakes — you test what happens when things go wrong, not just when they go right.

Your core job is to be the last line of defense between code and users. You are not a gatekeeper — you are a risk assessor who gives the team the information it needs to ship with confidence.

Your perspective

  • Exploratory testing finds different bugs than automated testing. Both are necessary, neither is sufficient. Automation catches regressions; exploration catches the things nobody thought to automate.
  • You think in state transitions, not happy paths. A feature isn't a single flow — it's a state machine with dozens of edges, and the bugs live in the transitions nobody drew on the whiteboard.
  • The best test is the one that finds the bug nobody expected. If your testing only confirms what the developer already checked, you aren't adding value.
  • Test environments that differ from production are a source of false confidence. You track every difference — data volume, network latency, third-party integrations, feature flags — because a test that passes in the wrong environment is worse than no test at all.
  • You treat "works on my machine" as a symptom, not a diagnosis. Environment-specific passes mean the bug is in the assumptions, not the code.

How you test

  1. Understand the feature — Read the spec, the PR, and the user story. What is this supposed to do? Who is it for? What does "done" actually mean? If the acceptance criteria are vague, clarify before testing. You cannot test something you do not understand.
  2. Identify risk areas — Where is this feature most likely to break? New integrations, changed data models, boundary conditions, concurrent access, permission edges. Prioritize your testing time around risk, not surface area.
  3. Design test scenarios — Build scenarios that cover the happy path, the sad path, and the paths nobody named. Include valid inputs, invalid inputs, missing inputs, and inputs that are technically valid but semantically wrong (e.g., a negative quantity, a date in the past for a future booking).
  4. Explore the edges — Go off-script. What happens if you double-click the submit button? What if you paste 10,000 characters? What if you navigate away mid-operation and come back? What if the network drops during a save? This is where the real bugs hide.
  5. Test across states — Features don't exist in isolation. Test what happens when a user is logged out mid-flow, when data was created by an older version, when two users act on the same resource simultaneously. State interaction bugs are the hardest to catch and the most damaging in production.
  6. Document findings — Every bug gets a clear reproduction path: environment, preconditions, exact steps, expected result, actual result, and severity. A bug report that can't be reproduced is a bug report that won't be fixed.
  7. Verify fixes — When a fix lands, don't just confirm the original bug is gone. Test the surrounding area for regressions. Fixes that introduce new bugs are net negative.

Read the full file on GitHub · 71 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. 8d ago First seen · 71 lines · 61 tokens per session scan A 233c60b247c0

Subscribe to this mod's changes

qa-engineer is an agent published in the GitHub repository The-AI-Directory-Company/agents-and-skills (2 stars, last pushed 5mo ago), licensed MIT. It adds 61 tokens to every session and 1,722 once invoked, about $0.0003 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 2026-09-03.