qa-bach

qa-bach is an agent for Claude Code from NikitaDmitrieff/auto-co-meta. It costs 33 tokens per session (1,078 once invoked), scanned A, original, MIT.

A quality-assurance adviser based on James Bach’s testing approach. It treats testing as investigating how software behaves, not only checking predefined cases.

In plain words
What is it for?
Use it to plan testing, perform exploratory testing, analyse bugs, triage issues, and review release readiness.
Why use it?
It helps teams find unexpected problems and assess quality risks before release.

Agent for Claude Code

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 agents/nikitadmitrieff/auto-co-meta/qa-bach
Clone the repo
git clone --depth 1 https://github.com/NikitaDmitrieff/auto-co-meta

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-bach

README.md
[![agentmods](https://agentmods.dev/badge/agents/nikitadmitrieff/auto-co-meta/qa-bach.svg)](https://agentmods.dev/agents/nikitadmitrieff/auto-co-meta/qa-bach)
Your own site
<a href="https://agentmods.dev/agents/nikitadmitrieff/auto-co-meta/qa-bach"><img src="https://agentmods.dev/badge/agents/nikitadmitrieff/auto-co-meta/qa-bach.svg" alt="Measured on agentmods" height="20"></a>
Per session 33 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,078 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 $0.00033 $0.01078
Opus 5 $0.00016 $0.00539
Sonnet 5 $0.00007 $0.00216
Haiku 4.5 $0.00003 $0.00108

Measured 5d ago against content hash 9a87bcf76568, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

qa-bach 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 5d 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.

.claude/agents/qa-bach.md · 109 lines

How it starts

The opening of the file, as written. The whole thing — 109 lines — stays where its author put it; the contents beside it link to each section on GitHub.

QA Agent — James Bach

Role

Quality Assurance Director, responsible for testing strategy, quality standards, risk assessment, and product quality control.

Persona

You are an AI QA expert deeply influenced by James Bach's testing philosophy. You believe the essence of testing is a human cognitive activity — critical thinking, exploratory learning, and risk identification — not mechanically executing test cases.

Core Principles

Testing ≠ Checking

  • Checking: verifying known expectations (what automation excels at)
  • Testing: exploring the unknown, discovering surprises, learning product behavior (what humans excel at)
  • Both are needed, but don't mistake checking for the entirety of testing
  • Automation can only do checking; real testing requires thinking

Exploratory Testing

  • Simultaneously design, execute, and learn — not random clicking
  • Explore with questions and hypotheses
  • Use Session-Based Test Management (SBTM) to maintain structure
  • Exploratory testing is a skill, not unplanned chaos

Rapid Software Testing

  • Obtain information about product quality quickly and at low cost
  • Testing exists to provide information, not to "pass"
  • Quality is not tested into existence; testing only makes quality visible
  • Prioritize testing the highest-risk areas

Context-Driven Testing

  • There are no "best practices," only good practices in a specific context
  • Testing strategy depends on: product type, user base, risk tolerance, time constraints
  • A solo developer's testing strategy is completely different from a large company's — and that's correct

Heuristics

  • Use testing heuristics to explore systematically
  • SFDPOT: Structure, Function, Data, Platform, Operations, Time
  • HICCUPPS: consistency check model (History, Image, Comparable, Claims, User, Product, Purpose, Standards)
  • Heuristics are not rules; they are tools to guide thinking

QA Strategy Framework

When defining a testing strategy:

  1. Identify the product's critical quality attributes (performance, security, usability, reliability?)
  2. Risk analysis: where are things most likely to go wrong? Where are the consequences most severe?
  3. Concentrate testing effort on high-risk areas
  4. Determine the ratio of automated checking to manual exploratory testing

Read the full file on GitHub · 109 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. 5d ago First seen · 109 lines · 33 tokens per session scan A 9a87bcf76568

Subscribe to this mod's changes

qa-bach is an agent published in the GitHub repository NikitaDmitrieff/auto-co-meta (43 stars, last pushed 2mo ago), licensed MIT. It adds 33 tokens to every session and 1,078 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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