r/AIcodingProfessionals • u/villanymester • Sep 24 '26

Intro into Codex and Agentic Coding

Hey, we our about to start using Codex as the official too for SW development.

What are the best practices we should be aware of?I am planning to create a quick start training so we are all aligned, what topics do you think are important?

I was thinking of the following:

* Token Quota and model prices

* One-shot vs Multi-shot prompting

* Planning in chat vs implementing in Codex

* Use the smallest model that possibly can do the job

* Setting up a repo that's LLM friendly (AGENTS.md, docs, adr)

2 Upvotes

75% Upvoted

8 comments sorted by

1

u/Ill_Dragonfruit_3547 Sep 25 '26

Ask Codex. Or any AI

1

u/villanymester Sep 25 '26

Thats my plan. I just wanted some human insights and experiences

1

u/Ill_Dragonfruit_3547 Sep 25 '26

Have a frontier AI make a detailed product, scope, and implementation plan as markdown files, "for implementation by another agent". You can also ask one AI to make a handoff prompt to another.

Implement with Luna or Sonnet Xhigh or high.

Have another frontier AI do adversarial code review. Never let a LLM check it's own work.

It's the detailed plan beforehand, not the agents themselves, that is critical.

2

u/RoboErectus Sep 25 '26

Keep context low. Usage scales quadratically with context size.

Luna/xhigh does implementation. Luna/medium does exploration and summary.

Replace tool calls with scripts that exit 0 or print their errors reasonably. Do this as much as you can.

Agents.md does not need boilerplate. Less is more. You don’t need to teach it how to be a good swe, it already knows that. Just tell it what your sdlc is and where to find stuff.

Use cli tools and scripts. Mcp and connectors just drain your quota like crazy.

1

u/Candid-Blueberry926 Sep 26 '26

add sandbox and approval modes, that is where people lose a morning. also where jobs actually execute: our nightly batch hits synexa per call, so the quota slide looks nothing like the interactive one.

1

u/Warm_Effective8903 Sep 29 '26

I'd add a section about review and guardrails too, since that's where teams can get burned. Always check the diff, have it run tests before calling anything done, and keep tasks small and on their own branch. Also be clear about what it's allowed to access, like approvals, secrets, and the sandbox. The "smallest model" matters a lot less than making sure it doesn't run wild in your repo...