Codex Test Gen

by sd0xdev

Codex Test Gen is a Quality skill for Claude Code, published by sd0xdev in sd0x-harness.

188 stars24 forkson sd0xdev/sd0x-harnessAdded 2026/09/06Repository updated 2026/09/05

View source on GitHub Download repo ZIP

agent-harnessclaude-codeclaude-code-plugincodexharness-engineeringskills

Install in seconds

Install Codex Test Gen

Copy Codex Test Gen into your Claude Code skills folder. Run the command in your terminal, or review the source on GitHub before installing.

terminal

npx degit https://github.com/sd0xdev/sd0x-harness/tree/main/skills/codex-test-gen ~/.claude/skills/codex-test-gen

Requires Node.js. Downloads this skill only — not the rest of the repository — into your Claude Code skills folder.

Without Node.js

git clone https://github.com/sd0xdev/sd0x-harness.git

Clones the whole repository, then copy the skill’s own directory into your skills folder yourself.

In this catalog

Source file: skills/codex-test-gen/SKILL.md in sd0xdev/sd0x-harness
Installs to: ~/.claude/skills/codex-test-gen
Collection: One of 25 skills cataloged from this repository
Category: Quality — 1745 skills

What Codex Test Gen does

Codex Test Gen routes to the test-review workflow to generate new unit tests for specified functions. Use it when you need tests written from existing code, not coverage review or integration tests.

Codex Test Gen is cataloged under Quality on DirSkills. Codex Test Gen comes from a repository tagged agent-harness, claude-code, claude-code-plugin, codex and harness-engineering.

Documentation

README

From the original repository

Codex Test Gen

Thin entry-point skill — routes to the parent skill for full workflow.

This skill delegates to test-review for the underlying transport. As a thin entry point it dispatches nothing itself, so it holds no transport grant. The generation-specific prompt template is at @skills/test-review/references/codex-prompt-test-gen.md.

See @skills/test-review/SKILL.md

Variant

This is the Generation variant — creates new unit tests for specified functions.

Trigger

Keywords: generate tests, write tests, create tests, codex-test-gen

When NOT to Use

Reviewing existing test coverage (use /codex-test-review)
Code review (use /codex-review-fast)
Writing integration/e2e tests (use /post-dev-test)

Commands Codex Test Gen provides

Slash commands named in this skill’s SKILL.md, listed in the order they first appear.

/codex-test-review
/codex-review-fast
/post-dev-test

Frequently asked about Codex Test Gen

What else does sd0xdev publish alongside Codex Test Gen?
Codex Test Gen is one of 25 skills that DirSkills catalogs from sd0xdev/sd0x-harness, the repository it ships in. Its siblings there include Adr, Architecture Design and Ask. Each one is a separate skill with its own page in this directory, installs the same way Codex Test Gen does, and is maintained by sd0xdev in that same repository. The rest of the collection is listed on the sd0xdev/sd0x-harness page.
How does Codex Test Gen compare to other Quality skills?
Codex Test Gen ranks #1619 by stars among the 1745 Quality skills in this catalog. The most-starred ones next to it are Benchmark, Benchmark Optimization Loop and API Design Patterns. DirSkills ranks by the star count of the repository each skill ships in, so that order reflects how popular those repositories are rather than any review of Codex Test Gen against them. Open each page to compare what they document and how they install.