AI tool
Codex apps for sale
Apps prompted into existence with Codex and listed for sale by the builder who never launched them. Most are 60 to 90 percent built with a working deploy. Open the repo in your IDE, point your AI at the rest, and ship the launch.
0 listings · Updated continuously
About this collection
If you have ever spent a weekend prompting an MVP into existence with Codex, you know how easy it is to start. The deploy works, the auth flows, the dashboard renders. Then Monday hits, the launch list never gets done, and the project lands in an archive folder. This page is the marketplace for those projects, listed by the founders who moved on to the next prompt.
Codex is good at Test-aware code generation, Strong TypeScript types, and Multi-file context. Most listings on this page are Full stack TypeScript apps, API endpoints and backend logic, and Test-driven implementations. Handoff tends to be straightforward because the buyer can open the same repo in Codex and pick up the original context, instead of starting from a cold readme.
Every listing here is a real project with working code. Most are 60 to 90 percent built and most close between $300 and $5,000. You email the founder directly from any listing. We never take a commission on the sale.
Current listings
Browse all projects →No codex apps for sale listed right now. Check back soon, or browse all projects.
Before you buy
What to look for
The five checks that separate a great listing from a regret. Run through them before any wire transfer goes out.
- 01
Open the deploy URL first
Click around for ten minutes before you read a line of code. If the core flow works in your browser, you are most of the way home. If it does not, ask the founder why before going further.
- 02
Read the README and the AI rules file
Good Codex listings ship with a clear README plus any agent rules file (.cursorrules, claude.md, AGENTS.md). The rules file tells you how the AI was steered. Missing rules file usually means inconsistent code.
- 03
Run it locally
Clone the repo, install, run. If the local environment is one command away, the founder kept things tidy. If it takes an hour to boot, expect rough edges elsewhere.
- 04
Inspect: UI polish and visual design
Codex projects often need attention here. Verify the founder addressed it, or budget time to fix it after handoff.
- 05
Inspect: Frontend animation
Codex projects often need attention here. Verify the founder addressed it, or budget time to fix it after handoff.
- 06
Ask for a 20 minute walkthrough
Most founders will hop on a call to walk you through the codebase. Twenty minutes saves you a week of cold reading. Use it to ask the awkward questions before you wire money.
After you buy
How to take it over
The hardest middle is already done. Four steps to turn a dormant repo into something live again.
- Step 01
Clone and run
Get the project running locally before signing anything. Most Codex projects boot with a single install command. If yours does not, that is a conversation to have with the founder up front.
- Step 02
Open it in Codex itself
Codex tends to leave good tests behind. Run them first. Whatever passes is solid ground to build on.
- Step 03
Map what works versus what does not
Make a two column list while clicking through. AI agents work better when you point them at one specific broken thing at a time, instead of asking for a global cleanup.
- Step 04
Ship the smallest possible launch
Most stalled projects need less than people think to be useful. Pick the one flow that already works, polish it, and put it in front of users. The rest can ship after.
About Codex
What Codex is good at, and where it tends to stop short.
OpenAI's coding agent with terminal and IDE integrations. Known for test-aware code and strong TypeScript fluency.
Typically builds
- Full stack TypeScript apps
- API endpoints and backend logic
- Test-driven implementations
Strengths
- Test-aware code generation
- Strong TypeScript types
- Multi-file context
Where buyers should inspect
- UI polish and visual design
- Frontend animation
- Design decisions when the prompt is vague
FAQ
Common questions
- How do I take over a Codex app I bought on Failedups?
- Clone the repo, install dependencies, and open it in Codex itself if you can. Using the same tool that built the app gives you the original context with no setup. Ask the AI to walk you through the broken parts and the agent rules file. Most Codex apps are running locally inside an hour.
- Is the code from Codex production ready out of the box?
- It depends on the listing. Many Codex apps work end to end for the happy path but need polish on auth edge cases, deploys, and tests. The buyer's checklist on this page calls out the parts Codex projects most often need attention on. Inspect the deploy and the README before paying.
- Can I keep developing in a different IDE after buying a Codex app?
- Yes. The codebase is just code. Codex does not lock you in. Many buyers continue in Cursor, Claude Code, Windsurf, or whatever they were already using. The agent rules file usually transfers cleanly between similar tools.
- How much do Codex apps usually sell for?
- Most close between $300 and $5,000. AI built MVPs without users land at the lower end. Codex apps with paying customers, a polished UI, or a meaningful audience can clear several thousand. Each listing sets its own price and the founder decides if it is negotiable.
- Are Codex apps available with a cofounder option instead of a sale?
- Yes. Plenty of Codex listings open up to a cofounder match instead of a buyout. See the looking for cofounder collection for current listings. Cofounder deals are equity only, no upfront cash.
- Does Failedups take a commission on a Codex app sale?
- No. The price you agree on with the founder is the price you take. We never broker or hold the transaction. Listing is free, browsing is free, and the only thing we charge for is an optional one-time visibility boost on a specific listing.
Sitting on a stalled Codex app?
Five minutes to list it, free. Buyers in this collection are looking for exactly the kind of project you stopped touching last month.
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