{"slug":"codex-cli-small-feature","title":"Implement a small feature that already has acceptance notes","summary":"Codex CLI builds a feature described as observable behavior, runs the tests you name, and leaves unrelated files alone.","agent":"Codex CLI","agentSlug":"codex-cli","category":"Coding","categorySlug":"coding","roles":["Software engineer"],"roleSlugs":["software-engineer"],"industries":["Software"],"industrySlugs":["software"],"jobs":["shipping-code"],"topic":"Dev & Coding","topicSlug":"dev-and-coding","score":17,"difficulty":"medium","estCost":"Codex on a ChatGPT plan. Local compute is yours.","costTier":"low","timeSaved":"A focused implementation pass when acceptance notes already exist.","prompt":"Implement the feature described in ACCEPTANCE. Those lines are the spec. Do not add settings, flags, or screens they do not mention.\n\nFollow AGENTS.md if the repo has one. If it conflicts with ACCEPTANCE, stop and ask.\n\nRun the test command. Update or add tests so each acceptance line has one assertion you can point to.\n\nDo not commit unless I ask. Show the diff stat first.\n\nACCEPTANCE:\nTEST COMMAND:","steps":[{"title":"Write acceptance as observable behavior","detail":"'Make it faster' is not a line Codex can satisfy honestly. 'The export includes a created_at column' is."},{"title":"Start Codex CLI in the repo","detail":"The CLI docs are the install source. If the repo has AGENTS.md, the prompt tells Codex to follow it."},{"title":"Check that each acceptance line has a test","detail":"The prompt requires a pointer from line to assertion. Missing pointers go back into the session."},{"title":"Commit when the diff stat matches the spec","detail":"You commit. The prompt refuses to commit on its own."}],"sourceUrl":"https://learn.chatgpt.com/docs/codex/cli","sourceNote":"Official documentation URL, checked when this seed was written. The prompt and steps are an original AI Playbook Gems playbook, not a quotation of a customer story, and have not been re-run.","date":"2026-09-18","verified":false,"status":"unverified","sponsorUrl":"","metrics":[{"label":"Hands-on time","value":"Spec writing plus diff review"},{"label":"You still approve","value":"Commit and release"},{"label":"Cost bucket","value":"Low"}],"faq":[{"question":"Has this Codex CLI playbook been re-run for the catalog?","answer":"No. Status is unverified. Paste the prompt, keep the version that worked, and do not treat the time or cost lines as measurements."},{"question":"What if there is no AGENTS.md?","answer":"The prompt says to follow it when present. Absence is fine. Do not let the agent invent a new project policy file unless you asked for one."}],"url":"https://aiplaybookgems.com/usecases/codex-cli-small-feature","jsonUrl":"https://aiplaybookgems.com/api/usecases/codex-cli-small-feature"}