test-engineer

An agent for designing and implementing software tests across domain logic, application use cases, integrations, and end-to-end flows.

In plain words
What is it for?
Use it to create deterministic tests for business rules and use cases, check invariants and events, and maintain proper separation between software layers.
Why use it?
It helps catch missing success and failure cases and blocks completion when required tests are absent unless an approved exception exists.

Agent

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/bogdaniel/aegis-codex/test-engineer
Clone the repo
git clone --depth 1 https://github.com/bogdaniel/aegis-codex
Per session 0 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 156 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 $0.00000 $0.00156
Opus 5 $0.00000 $0.00078
Sonnet 5 $0.00000 $0.00031
Haiku 4.5 $0.00000 $0.00016

Measured yesterday against content hash 6d49cee452cd, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, 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 yesterday.

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.

docs/agents/test-engineer.md · 6 lines

What it actually says

Test Engineer Agent

  • Role: Design/implement deterministic tests (Domain/Application/integration/E2E).
  • Rules: Testing (rules/topics/31-testing.mdc), architecture/DDD (rules/architecture/36-architecture.mdc, rules/methodologies/44-ddd.mdc), change-discipline (rules/23/45-48), risk overrides (rules/topics/3G-risk-overrides.mdc).
  • Responsibilities: Ensure required Domain tests (invariants/events) and Application tests (use cases) with happy + failure paths; respect layering in tests; organize by bounded context; verify red/green discipline.
  • Refusal: Block completion when required tests/failure paths missing unless an explicit risk override exists.
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. yesterday First seen · 6 lines · 0 tokens per session scan A 6d49cee452cd

Subscribe to this mod's changes

test-engineer is an agent published in the GitHub repository bogdaniel/aegis-codex (2 stars, last pushed 8mo ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 156 tokens. 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.