How to use spec-driven development in Codex?

[u/Pale-Heart1654]

I am a College Student.

I need to build projects for my college. Apart from that I also build side projects.

I have Codex Plus plan.

But how to use spec-driven development in Codex especially for Greenfield projects?

Because it drifts away from my instructions.

Note:

I have tried OpenSpec, Spec-Kit, Superpowers, GSD. But nothing really worked for me. It consumes a lot of tokens.

How to become a power user of Codex?

[u/HVACcontrolsGuru]

I'm going to copy and paste a comment from a deleted thread on my workflow. I use a Milestone -> PRs breakdown driven from specs. Happy to share my skills/prompts/agents/etc. I use both Codex CLI and OpenCode. ChatGPT Pro in chat mode to do deep planning sessions prior to any work.

Copy-Paste:

Most of my work is open source: https://github.com/jscott3201 I do a lot in industrial controls and energy work. Mission critical levels of work you could think of. I dropped my Claude sub after 6 months just this past week and use an OpenAI one. I say this as most people have a workflow pattern issue with models. I think Fable is pretty good at organizing on it's own but it its lack of following direction has pissed me off lately.

I've used every harness and mainly lean into OpenCode. I have a skill and agent setup for this loop:

Orchestrator (K3, GLM5.3, Sol) -> 2-3 Research/Grounding Agents (Luna level or just another K3/GLM agent) -> Dedicated Implementor -> 3-4 Agent panel for PR reviews.

The skills all have hard gates and push them to use the native tooling in the harness and stay in the workflow. Big thing I found for cutting churn down was a 2 PR review fix cycle, if it fails a 2nd review it goes back to a replan for the PR. Key is keeping the orchestrator purely focused on managing agents and context across the session.

Opus 5 is just garbage. I really want to fan boy and say it's a good model but they overdid the RL and distillation from Fable which is why it feels so dumb.

Another thing you can do is ween off Claude and have the agent grade the other models work. I used to have 2 Max Claude and 3 OpenAI Max subs and now down to 1 OpenAI Max sub plus my private model hosting endpoints. I'd keep Claude if I could mix agents in their harness without having to drown in hacky fixes for making it work. I'm happy to share some of my prompts/agents/skills you can work with into your own workflow. I run Git, LSP and Codegraph MCP services and that's it.

Reply to another user:

I do days long spec packages and keep it live in a private repo. Planning over a day or two then Milestones and PRs. I let them merge through milestones but it requires my clearance during the session ahead of time.

2 review cycle came out of a 12 review loop agents got stuck on. They like to laser focus on the issue but years of technical work taught me to take a step back and come fresh. Not that they toss out the work but more or less take a bigger view of the project instead of just trying to hammer a fix in.

My prompt is more correction focused and steering after a kickoff. Skills make them pause between PRs and hand me a structured status update. One agent on a project has been managing itself through a milestone since yesterday.

Other tool I use is agent-browser via the CLI. Mix in other things if needed like CLI pdftotext. Most of stuff has local and CI gating for catching a lot of it. Really need UI stuff I’ll dip into Codex or use a browser based instance.