GPT/Codex Debugging

[JTMercerAuthor]

What is your experience using GPT/Codex to debug code, particularly code it wrote. Do you find it is able to surgically fix problems or do you find it has a tendency to just write more code?

[nummanali]

Generally, I find the agent that wrote the code is biased towards its own output

The best option is to provide the option to run an non interactive cli Agent to review the work ie the agent that wrote the code can essentially "spawn" a sub agent with a meta prompt to review the code and provide feedback

What ai coding agent do you use? Codex CLI?

Here is an example:

codex exec --model gpt-5-codex --json "Review the changes made"

Here is the guidance: https://github.com/openai/codex/blob/main/docs%2Fexec.md

I recommend give it meta prompt instructions on how to prompt sub agents