{"slug":"codex-cli-build-from-a-plan-and-a-container","title":"Build from a plan and a container and leave the ship to me","summary":"Codex CLI handles this as a draft: Stack Overflow told OpenAI that two engineers gave Codex a development environment and a plan, and that a container plus that plan was how a small team built Stack Overflow for Agents. You still review the diff and you still ship.","agent":"Codex CLI","agentSlug":"codex-cli","category":"Coding","categorySlug":"coding","roles":["Software engineer","Founder"],"roleSlugs":["software-engineer","founder"],"industries":["Software"],"industrySlugs":["software"],"jobs":["shipping-code"],"topic":"Dev & Coding","topicSlug":"dev-and-coding","score":18,"difficulty":"medium","estCost":"A Codex session with a container and a plan you already wrote. The OpenAI article does not list a price for that session.","costTier":"medium","timeSaved":"The first build against a plan you already have. Stack Overflow says two engineers had a product within a few weeks. That is their figure, not a measurement from this catalog.","prompt":"Build only what this plan describes. The plan and the container are the source of truth. Do not widen the plan.\n\nWork inside the container I point you at. If you cannot see the plan or the container, stop.\n\nWhen you stop, summarize the diff in a few sentences and list anything in the plan you did not implement. Do not push. Do not deploy. Do not merge. Do not invent a timeline for how long this would take a larger team.\n\nI review the diff and I decide what ships.","steps":[{"title":"Write the plan and point Codex at one container","detail":"The OpenAI article, dated 16 Oct 2026, says Stack Overflow for Agents began with a hypothesis and two engineers using Codex. They gave Codex a development environment and a plan. Alexandra Lato, VP of Product, is quoted: they were able to throw a container at it and say, this is our plan, help us build it."},{"title":"Read the diff against the plan","detail":"The article says that within a few weeks they had a full-fledged product. That is Stack Overflow's account of their own team. Check the diff yourself before you treat a run as finished."},{"title":"Stop","detail":"You ship. The article describes engineers working with Codex. It does not say Codex merged or deployed on its own."}],"sourceUrl":"https://openai.com/index/stack-overflow-chatgpt-plugin/","sourceNote":"OpenAI customer story, dated 16 Oct 2026, titled Stack Overflow for Agents triples signups with ChatGPT plugin. Fetched on 18 Oct 2026. It says two engineers gave Codex a development environment and a plan, quotes Alexandra Lato on throwing a container at Codex with the plan, and says they had a product within a few weeks. Figures about a ChatGPT plugin tripling registrations are a different part of the same article and are not this playbook. Prompt and stop rules are an AI Playbook Gems adaptation, not a vendor quote; unverified.","date":"2026-10-18","verified":false,"status":"unverified","sponsorUrl":"","metrics":[{"label":"Hands-on time","value":"Reviewing the diff against the plan"},{"label":"You still approve","value":"What ships"}],"faq":[{"question":"Has this Codex CLI playbook been re-run for the catalog?","answer":"No. Status is unverified. The OpenAI article was fetched on 18 Oct 2026. The prompt is an adaptation of Stack Overflow's account, not a re-run."},{"question":"What stays human?","answer":"The plan, the review, and the ship decision. The article's 'few weeks' figure is Stack Overflow's, about their own product."}],"url":"https://aiplaybookgems.com/usecases/codex-cli-build-from-a-plan-and-a-container","jsonUrl":"https://aiplaybookgems.com/api/usecases/codex-cli-build-from-a-plan-and-a-container"}