Reusable instructions for testing and code review in Codex

Sunny Rajpal — Sat, 12 Sep 2026 14:18:23 +0000

I maintain Codex Dev Workflows, a free, open-source plugin with 12 skills. It's for developers who keep repeating the same instructions when testing features, reviewing changes, or continuing unfinished work.

Here's a small review example. This function should return None for an empty list:

def average(values):
    return sum(values) / len(values)

Choose $code-review and ask:

Review this function against that requirement. Explain the bug and suggest the smallest fix. Do not edit files.

For an empty list, the function divides by zero. A useful review should identify that input, suggest an empty-list check, and say whether it actually ran any tests.

The plugin puts review instructions into reusable skill files. You can read and adapt them. It uses your existing Codex model and tools, so you still need to check its findings.

Install on OpenAI

Source and more examples

What instructions do you keep repeating during code reviews?

Drafted with AI assistance.

DEV Community: Sunny Rajpal

Reusable instructions for testing and code review in Codex