Guide · Agent skill

How to use the Test Master agent skill: setup and examples

Updated 2026-10-29 · written with AI from the project's own documentation and checked against our catalogue data

Test Master is an agent skill that gives an AI coding agent a structured QA specialist's approach to testing. This guide explains what an agent skill is, how to install test-master, how to ask for testing work in plain language, and what the skill needs and does not do. By the end you will be able to add the skill, point the agent at a codebase and get test files, coverage analysis or a defect report.

Test MasterJeffallan/claude-skills · MIT Download the skill

Quick start

1Download the ZIP. Download the test-master ZIP from the skill page.
2Unzip into a skills folder. Unzip it into ~/.claude/skills/ for personal use or into a project's .claude/skills/ folder for one repository.
3Or upload in the Claude apps. In the Claude apps, go to Settings → Capabilities → Skills and upload the ZIP.
4Check your test runner. Make sure the project has Jest, Vitest, pytest or another supported runner, and k6 or Artillery if you plan performance tests.
5Make a natural request. Describe the module and the kind of test or report you want, naming the framework where relevant.
6Review and run the output. Read the generated tests, run them, and check that failures are classified and coverage gaps are flagged.

What is an agent skill and what does test-master make the agent do?

An agent skill is a folder of instructions and reference files that an AI agent loads when a task matches the skill's description. test-master is the skill for testing work. Its SKILL.md describes a core workflow: define scope, create a strategy, write tests, execute them, and report findings with severity ratings and fix recommendations.

Once installed, the agent can generate test files, plan mocking strategies, analyse coverage gaps, design test architectures, and produce test plans and defect reports across functional, performance and security testing.

Write unit, integration and end-to-end tests with meaningful descriptions and specific assertions
Plan mocking and test architecture
Analyse coverage gaps and flag them explicitly
Produce test plans and defect reports with Critical, High, Medium or Low severity
Follow reference guides on k6 load testing, OWASP-style security checks, flaky-test debugging and test-first development

Install the test-master skill with the ZIP download

Download the test-master ZIP from the skill page. Then choose one of the following locations, depending on whether you want the skill for all your projects or for one repository.

For a personal install available across projects, unzip the download into ~/.claude/skills/. For a single project, unzip it into that project's .claude/skills/ folder so it travels with the repository.

If you use the Claude apps instead of a local setup, upload the ZIP under Settings → Capabilities → Skills.

Personal: ~/.claude/skills/
Per project: .claude/skills/ inside the project
Claude apps: Settings → Capabilities → Skills, then upload the ZIP

Ask for testing work with natural requests

You do not need to type the skill name. The skill's description lists the situations it applies to, so ordinary requests about testing should match. Name the file, function or module you care about and say what kind of test or report you want.

Requests that match the skill include writing unit, integration or E2E tests, creating a test strategy, analysing coverage gaps, performance testing with k6 or Artillery, security testing with OWASP methods, and debugging flaky tests.

Write Jest unit tests for src/pricing/discount.ts, including error cases
Find the coverage gaps in the auth module and tell me which branches are untested
Why does checkout.spec.ts fail intermittently? Diagnose it and suggest a fix
Draft a regression test plan for the release, with severity ratings for any defects found

What a good test looks like with this skill

The skill's quick-start example shows the patterns it enforces. Each test has a plain-English description and asserts a specific outcome rather than just truthiness. Error cases such as negative prices are tested as well as the success path.

The same structure applies to pytest, where tests are written as def test_ functions with assert statements.

describe('calculateDiscount', () => {
  it('applies 10% discount for premium users', () => {
    const result = calculateDiscount({ price: 100, userTier: 'premium' });
    expect(result).toBe(90);
  });

  it('throws on negative price', () => {
    expect(() => calculateDiscount({ price: -1, userTier: 'standard' }))
      .toThrow('Price must be non-negative');
  });
});

What the skill needs and its safety limits

The skill needs a codebase or test environment the agent can read and run tests against. It works with Node.js or Python test runners such as Jest, Vitest or pytest, depending on the project. Performance tests need k6 or Artillery if you use them.

The skill does not run scripts and does not use the network, according to its listing. Its MUST NOT rules include never calling real APIs or databases in unit tests and never using production data in tests; use fixtures or factories instead.

The skill provides checklists and methods. It is not a substitute for a professional penetration test. Only run load or security tests against systems you own or have permission to test.

Requires: Node.js or Python test runner, a codebase or test environment, and k6 or Artillery for performance tests if used
Runs scripts: no
Uses network: no
Do not use production data in tests
Do not run load or security tests against systems you do not own or have permission to test

Tips for better results

Give the agent a concrete target and a runner. Requests that name the module, the framework and the environment get more usable output than general requests about quality.

Ask for failure classification when tests break. The skill's workflow separates assertion errors from environment or flakiness problems, and it expects flaky tests to be isolated and fixed rather than re-run until green.

Name the test framework (Jest, Vitest or pytest) in the request
Ask for both happy-path and edge-case tests, such as empty input, null and boundary values
Ask for a report with severity ratings when you want findings rather than code
Review generated tests before committing, especially assertions

What people use it for

Writing Jest or Vitest unit tests for pricing, validation or other pure functions, including error cases
Generating Supertest integration tests for API endpoints, such as checking 201 on valid input and 400 on invalid email
Planning a regression test strategy and writing a test plan before a release
Diagnosing a flaky test suite by isolating ordering dependencies and async handling
Producing a defect report with severity ratings and fix recommendations

Frequently asked questions

How do I install the test-master skill?

Download the test-master ZIP from the skill page and unzip it into ~/.claude/skills/ for personal use, or into a project's .claude/skills/ folder for one repository. In the Claude apps, you can instead upload the ZIP under Settings → Capabilities → Skills.

Is test-master free to use?

The skill is listed under the MIT licence. Check the licence file in the repository for the terms that apply to your use.

What do I need to run test-master?

You need a codebase or test environment the agent can read and run tests against, plus a runner such as Jest, Vitest or pytest. For performance tests, you also need k6 or Artillery if you use them.

Does test-master run scripts or access the network?

According to its listing, the skill does not run scripts and does not use the network.

Can test-master replace a professional penetration test?

No. The skill provides checklists and methods for security testing, but it is not a substitute for a professional penetration test.

Which test frameworks does test-master support?

The skill covers Node.js and Python test runners such as Jest, Vitest and pytest, and its quick-start example shows Jest with a pytest equivalent described. It also has reference guides for E2E testing with Playwright and performance testing with k6.

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Our verdict

Test Master suits software developers and QA engineers who work in a codebase with Jest, Vitest or pytest and want structured help with unit, integration and E2E tests, coverage gaps, flaky tests and defect reports. It is less useful for non-technical users with no code to test, and it is not a replacement for a professional security audit.

Download the skill