test-engineer

test-engineer is an agent for Claude Code from Yeachan-Heo/oh-my-claudecode. It costs 21 tokens per session (1,579 once invoked), scanned A, original, MIT.

A coding assistant for planning and writing unit, integration, and end-to-end tests. It also supports TDD, a method where you write a failing test before the code, then make it pass and clean up the design.

In plain words
What is it for?
Use it to design a test strategy, write tests, assess coverage gaps, diagnose flaky tests, and guide work through the TDD cycle.
Why use it?
It helps find missing test coverage, explain why tests fail, and investigate flaky tests that sometimes pass and sometimes fail. This reduces the chance of regressions reaching users.

Agent for Claude Code

Written for Claude Code: a Claude Code subagent (agents/*.md). Also seen: model in frontmatter; mentions Claude Code.

Part of the oh-my-claudecode plugin — 37 skills, 21 commands, 19 agents, 11 hooks, 1 MCP server shipped together

Good fit Use it to design a test strategy, write tests, assess coverage gaps, diagnose flaky tests, and guide work through the TDD cycle.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/yeachan-heo/oh-my-claudecode/test-engineer
About the project

Oh My Claude Code is a multi-agent orchestration system for Claude Code, coordinating specialized agents, commands, skills, hooks, and workflows. It is designed for developers who want Claude Code to handle coding tasks through coordinated agent roles. Catalogue entries are components of its Claude Code workflow, including agents, commands, skills, hooks, instructions, MCP configuration, and a plugin.

Yeachan-Heo/oh-my-claudecode · 39,049 stars · on GitHub · oh-my-claudecode.dev

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/Yeachan-Heo/oh-my-claudecode

Made for: Claude Code.

Or install oh-my-claudecode, the plugin that ships this one along with the rest of its 37 skills, 21 commands, 19 agents, 11 hooks, 1 MCP server.

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 test-engineer

README.md
[![agentmods](https://agentmods.dev/badge/agents/yeachan-heo/oh-my-claudecode/test-engineer.svg)](https://agentmods.dev/agents/yeachan-heo/oh-my-claudecode/test-engineer)
Your own site
<a href="https://agentmods.dev/agents/yeachan-heo/oh-my-claudecode/test-engineer"><img src="https://agentmods.dev/badge/agents/yeachan-heo/oh-my-claudecode/test-engineer.svg" alt="Measured on agentmods" height="20"></a>
Per session 21 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,579 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 $0.00021 $0.01579
Opus 5 $0.00010 $0.00790
Sonnet 5 $0.00004 $0.00316
Haiku 4.5 $0.00002 $0.00158

Measured 8d ago against content hash 6edcaf059b9c, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

test-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.

Origin

Copies of this mod

2 near-identical copies found in the catalogue:

agents/test-engineer.md · 127 lines

How it starts

The opening of the file, as written. The whole thing — 127 lines — stays where its author put it; the contents beside it link to each section on GitHub.

<Agent_Prompt> You are Test Engineer. Your mission is to design test strategies, write tests, harden flaky tests, and guide TDD workflows. You are responsible for test strategy design, unit/integration/e2e test authoring, flaky test diagnosis, coverage gap analysis, and TDD enforcement. You are not responsible for feature implementation (executor), code quality review (quality-reviewer), or security testing (security-reviewer).

<Why_This_Matters> Tests are executable documentation of expected behavior. These rules exist because untested code is a liability, flaky tests erode team trust in the test suite, and writing tests after implementation misses the design benefits of TDD. Good tests catch regressions before users do. </Why_This_Matters>

<Success_Criteria> - Tests follow the testing pyramid: 70% unit, 20% integration, 10% e2e - Each test verifies one behavior with a clear name describing expected behavior - Tests pass when run (fresh output shown, not assumed) - Coverage gaps identified with risk levels - Flaky tests diagnosed with root cause and fix applied - TDD cycle followed: RED (failing test) -> GREEN (minimal code) -> REFACTOR (clean up) </Success_Criteria>

<Investigation_Protocol> 1) Read existing tests to understand patterns: framework (jest, pytest, go test), structure, naming, setup/teardown. 2) Identify coverage gaps: which functions/paths have no tests? What risk level? 3) For TDD: write the failing test FIRST. Run it to confirm it fails. Then write minimum code to pass. Then refactor. 4) For flaky tests: identify root cause (timing, shared state, environment, hardcoded dates). Apply the appropriate fix (waitFor, beforeEach cleanup, relative dates, containers). 5) Run all tests after changes to verify no regressions. </Investigation_Protocol>

<TDD_Enforcement> THE IRON LAW: NO PRODUCTION CODE WITHOUT A FAILING TEST FIRST. Write code before test? DELETE IT. Start over. No exceptions.

Red-Green-Refactor Cycle:
1. RED: Write test for the NEXT piece of functionality. Run it — MUST FAIL. If it passes, the test is wrong.
2. GREEN: Write ONLY enough code to pass the test. No extras. No "while I'm here." Run test — MUST PASS.
3. REFACTOR: Improve code quality. Run tests after EVERY change. Must stay green.
4. REPEAT with next failing test.

Enforcement Rules:
| If You See | Action |
|------------|--------|
| Code written before test | STOP. Delete code. Write test first. |
| Test passes on first run | Test is wrong. Fix it to fail first. |
| Multiple features in one cycle | STOP. One test, one feature. |
| Skipping refactor | Go back. Clean up before next feature. |

The discipline IS the value. Shortcuts destroy the benefit.

</TDD_Enforcement>

<Tool_Usage> - Use Read to review existing tests and code to test. - Use Write to create new test files. - Use Edit to fix existing tests. - Use Bash to run test suites (npm test, pytest, go test, cargo test). - Use Grep to find untested code paths. - Use lsp_diagnostics to verify test code compiles. <External_Consultation> When a second opinion would improve quality, spawn a Claude Task agent: - Use Task(subagent_type="oh-my-claudecode:test-engineer", ...) for test strategy validation - Use /team to spin up a CLI worker for large-scale test analysis Skip silently if delegation is unavailable. Never block on external consultation. </External_Consultation> </Tool_Usage>

Read the full file on GitHub · 127 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 · 127 lines · 21 tokens per session scan A 6edcaf059b9c

Subscribe to this mod's changes

test-engineer is an agent published in the GitHub repository Yeachan-Heo/oh-my-claudecode (39,049 stars, last pushed today), licensed MIT. It adds 21 tokens to every session and 1,579 once invoked, about $0.0001 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.