Codex use cases
42 real things people got Codex to do, each with what they asked, how it went, and the prompt to copy.
Audit a feature's issues and hand them to an engineer's agent
An AI agent listed all issues with a feature and sent them to an engineer, whose own agent then addressed most of them automatically.
Automate a weekly arXiv paper triage
A weekly Codex automation searches arXiv for keywords, logs new papers to a CSV, sorts them into keep/skim/drop buckets and can check claims against Zotero.
Build a household dinner-suggestion app
A non-coder used Codex to build a local app that suggests dinners from pantry stock, garden produce, diets, appliances and weather.
Build a racing game from a single prompt
Codex made a racing game with multiple racers, eight maps and items from one prompt, acting as designer, developer and QA tester by playing it.
Build and publish a BaZi chart reading agent
Built solo with coding agents, an agent computes BaZi charts, interprets them, detects language and takes on-chain payments for readings.
Build custom real estate tools for offers and deal tracking
A rental owner used Codex to build tools for formulating offer prices, building property analysis reports with field photos, and tracking transactions under contract.
Build game architecture and animation merging with Codex
A commenter had Codex do fundamental architecture work for their game, reading engine docs and implementing better animation merging.
Cancel an Amazon subscription and get a refund
Codex navigated Amazon settings to cancel a subscription, then chatted with customer service and secured an immediate $15 refund.
Debug overnight with a long-running agent
The author leaves Codex CLI running for hours to add debug prints and test hypotheses against a reproducing unit test, often only to find the bug.
Design a personal website from a markdown spec
The author had Codex CLI read a design spec and iterated on it to design his personal site, and he can reuse the spec on other projects.
Diagnose Swift errors with ChatGPT from symptoms and code with ChatGPT
A Swift developer feeds error symptoms and code to ChatGPT to get a starting lead on the cause, then reviews the code it produces.
Email scheduled project summaries with Codex
A guide sets up a Codex automation that reads project files on a schedule and emails a weekly summary via the Gmail plugin.
Fill forms and review tax filings with Codex computer use
Secondhand accounts of OpenAI staff using Codex computer use for forms and PDFs, including one tax filing review that caught an error worth thousands.
Hand off coding sessions between agent accounts at usage limits
A developer built an app that tracks usage across multiple Codex and Claude Code accounts and auto-hands-off conversations when one hits its limit.
Handle family errands and recipe sorting with Codex
A communications professional had Codex email her son's doctor for a refill and sort 240 recipes down to 62 family-fit ones into an index, spreadsheet and Drive folder.
Hunt high-value Pokémon cards on eBay overnight
An engineer built a Codex agent that browses eBay listings, extracts PSA certificate numbers and cross-references known prices while he sleeps.
Make daily safe SEO fixes with a Codex automation
A scheduled Codex automation reviews analytics and SEO notes each morning, picks five safe fixes like internal links and metadata, and applies them.
Patch annoying software behavior by pointing an agent at it
Author had an agent debug a Hyper-V vmconnect fullscreen bug with a hook system, and pointed Codex at the Codex app to add features.
Plan a vacation with a custom Codex-built website
Claire had Codex research hotels, map them on Google Maps and deploy a trip site from her phone; its browser also navigated to checkout for an item.
Port the Copilot runtime to Rust agentically
Microsoft reportedly used agents to port its Copilot runtime to Rust for $120K, according to the headline.
Post a rendered video to Slack when integration fails
Codex read Slack feedback, edited and re-rendered a video, then used Computer Use to click Add file and post it in Slack.
Produce a track in Ableton Live by talking
An MCP server that lets Codex drive Ableton Live, used to write and mix a full song from chat messages.
Pull Substack post stats via computer use
Charlie Hills has Codex Computer Use open his Substack dashboard and collect figures for every published post, for apps lacking MCP connectors.
Race three models to build a Counter-Strike clone
InstantDB had Codex, Opus, and Gemini each try to build a multiplayer shooter.
Rank CRM prospects and draft outreach with Codex
A demo has Codex pull CRM data, rank top accounts, and build a 13-slide deck with per-account strategy and draft outreach emails.
Recommend a hotel from client notes using Codex
A travel advisor had Codex use client notes to recommend a Belmond hotel in Italy, checking live booking engines and generating a detailed Word doc.
Repair formal proofs for a verified garbage collector
Codex edited files and ran builds to repair CertiGC proofs; it handled local repair well, but humans had to check that its invariants preserved the specification.
Research Reddit customer pain points with a skill
The author replaced a Reddit research agent with a Codex skill that finds pain points, verifies communities, collects evidence, clusters problems, and analyzes commercial signals.
Resolve a Slack-reported issue with a coding agent
A Codex agent resolved an issue passed to it in about 40 minutes, and an ops agent verified the fix back in Slack.
Review Linux kernel patches
Google engineers launched Sashiko, an agentic AI code reviewer for the Linux kernel.
Run an AI software factory that opens, reviews, and merges PRs
A guide to building agents that open, review, and merge pull requests.
Run an autonomous employee-like agent for company tasks
Author runs a self-built autonomous agent on Codex, ChatGPT Plus, systemd and email that handles various company tasks, using a rolling context, diary and markdown wiki for memory.
Run Codex tasks on your Home Assistant config
An integration starts Codex CLI tasks against a Home Assistant config to diagnose failing automations, check dashboards for broken cards and create scripts.
Screen research papers against criteria
Codex reads a folder of PDFs to find articles that disagree with an argument, screens about fifty papers for a systematic review, and cleans messy CSV or Excel files.
Speed up Rust code by having agents iteratively optimize it
The post covers asking coding agents to make Rust code faster through repeated iteration.
Summarize months of notes in Logseq via CLI agent
User points Codex at the Logseq CLI docs so it can query and summarize journals and tagged job-application and project pages.
Summarize transcripts and build documents with Codex
A guide shows Codex summarizing transcripts into a Word doc, building an Excel revenue model and making carousel images from a document.
Triage email by voice while walking
Allie Miller used ChatGPT voice mode with Codex to triage important emails, draft replies, archive or delete items and log action items.
Turn tickets into merged pull requests with Claude Code
Pulls tasks from GitHub Issues or Linear, then runs Claude Code or Codex in isolated Kubernetes pods to carry each one through to a PR.
Turn tickets into merged pull requests with one-shot coding agents
Stripe describes its internal Minions coding agents that take tasks end to end into code changes; the post is a headline only.
Turn voice notes into Linear tickets and review analytics
The author built Codex skills that convert voice notes into formatted Linear tickets, review YouTube analytics weekly, and run nightly self-improvement automations.
Use Codex for non-coding chores
Commenters use Codex for Pi-hole upgrades, market research, wiki building, file search, PowerPoint edits, light Excel work, scraping, and data entry.