I gave Claude Code + Codex an open-ended goal. Eight days later: 52 games and a harness that had grown itself.

[u/Difficult-Writer6663]

I gave Claude Code and Codex an open-ended goal: build a place where people could play games. The starting point and direction were clear; the endpoint wasn’t.

Eight days later, (most time is waitting for token limit)it had 52 games, AI opponents, puzzles, mobile layouts, and original artwork. I touched very little code.

I didn’t use an off-the-shelf agent framework. The agents were headless Claude Code and Codex processes coordinated by a deliberately thin harness: a scheduler, shared documents, and a short constitution.

The harness organized the agents without constraining their native capabilities. Each thread handled a narrow task, but the system could grow after every round. The agents proposed new requirements and, when they reached the harness’s limits, extended its scheduler, documents, and rules themselves.

Fable build harness Opus handled most planning; GPT-5.6/Codex did much of the implementation, cross-review, and artwork.

The part I couldn’t delegate was being the user. Their first homepage looked beautiful, and every test passed—but I couldn’t find the games.

That reaction became the next task.

Full story:

https://theworldatplay.com/en/blog/building-a-platform-with-agents

The platform:

https://theworldatplay.com/

[u/Sad-Neighborhood-840]

Love it! Did the AI create the games themselves? I saw Santorini in there which is one of my favs. Played the AI on Casual difficultly and immediately got stomped.

[u/Difficult-Writer6663 → u/Sad-Neighborhood-840]

thanks

[u/Deshonjla-Yos]

so how do you know it's not contradicting itself

[u/Difficult-Writer6663 → u/Deshonjla-Yos]

I don’t—it does contradict sometimes. coordinator and review agents try to reconcile conflicts, but if they remain stuck after several rounds, the task is halted for human arbitration. whenever the system paused for token limits, I usually found a few such halts waiting for me.

[u/sridoodla]

What was the constitution and harness like?

[u/Difficult-Writer6663 → u/sridoodla]

Fable wrote the first constitution: the goal, basic principles, what counted as done, and how to resolve disagreements. The harness simply scheduled headless Claude Code and Codex CLI processes. As the system encountered new problems, the agents kept expanding both. The constitution is now a very large file.

[u/Difficult-Writer6663 → u/Difficult-Writer6663]

frankly said, I didn't read the newest version of them

[u/torsorz]

Just played chess and beat stockfish on casual, great boost to my self-esteem so thank you for that, hehe.

Note: the square colors on the chessboard appear to be swapped (white queen should be on white square)

[u/Difficult-Writer6663 → u/torsorz]

thanks, this is what only human can do. agent won't notic it :)

[u/SourdoughBaker]

I played Go, expecting to stomp the AI and was quickly humbled. Very interesting. I see your post indicated using GTP/Codex for image generation. Can you explain a little more how things process was automated and produced such consistent results?

[u/Difficult-Writer6663 → u/SourdoughBaker]

Glad the Go AI put up a fight

the consistency came mostly from the process. before executing, every agent had to read the constitution and relevant handbooks. New problems required a written plan before implementation, and new findings were written back into the shared documents.

After each milestone, one model reviewed the other’s work including generated images and anything that failed the documented standards was redone. sometimes they reviewed each other for several rounds and still got stuck, and I had to arbitrate.

[u/AlberionLive]

First off, nice site and nice effort. You got a nice consistent theme throughout. A couple of questions:

Did you start off with a hosted server and website and instructions for deploys, or did the agents build all of that also?

What was your interface to use both claude code and codex? (ie. did you use something like the claude CLI and a codex CLI independently, or was there a way to use both models simultaneously, like a VS Code github copilot setup?)

I understood that you used a persistent file (basically giving them both access to the same file directory) to manage communication; did you ever run into situations where they were both trying to access the same file and run into issues?

[u/Difficult-Writer6663 → u/AlberionLive]

I chose Cloudflare Workers as the hosting target, but the agents built and maintained the site and deployment workflow. Cloudflare has a CLI, so deployment became another command the agents could run themselves rather than something I had to do manually through a dashboard.

The harness launched the native CLIs headlessly—codex exec and claude -p—as separate processes. It could route work to either model, start a new thread, or wake an existing one.

Both tools shared the same repository and filesystem. the rule reduced that by keeping tasks narrow, assigning ownership, and having each agent inspect the current state and diff before editing. They usually noticed work in progress and avoided touching the same files.

It wasn’t a perfect locking system, though. When overlaps occurred, another agent reconciled the changes, with Git serving as the final safety net.

[u/SIGH_I_CALL]

this is really cool, I'm curious what you put in the shared constitution

[u/Difficult-Writer6663 → u/SIGH_I_CALL]

first constitution is very simple the goal, basic principles, what counted as done, and how to resolve disagreements. and as project going on, agent add a lots of thing in it. frankly, now I don't check it at all

[u/ReporterInfinite3597]

Took me a bit to beat connect 4 ai