How Hearth works

An app for making a game by talking to an AI. Say what you want to play, and it gets built on your computer.

Say it, and it is a folder

Type a sentence. Hearth names a folder after it and starts the chat there. No wizard, no template.

> a tiny roguelike where the walls move

~/Hearth/tiny-roguelike-walls-move

The game runs next to the chat

Your game plays on the right while the agent works on the left. It reloads when the agent finishes a change.

Part of a Hearth conversation: a message, the files the agent changed, and a request to allow a command.

Every file it changes shows up in the chat. Anything outside your folder asks first, and you choose how much it asks.

The agent checks its own work

After a change, the agent can open the game in a browser and check it still runs. A game that shares more makes the check sharper.

Any game at all crashes, blank screens, screenshots, whether anything moved

A game that shares more about itself where things are, what just happened, which level you are on

That is optional, and Hearth says what it could not check. How a game shares more

A tester that remembers

Ask, and a playtester plays your game. It belongs to the project, so it reads its own notes from last time and what you changed since. Its answer is about your edit.

It is not a good player, and it cannot tell you whether the game is fun. That is yours. It spends model calls on your own quota, against a budget you set. Its memory is a file you can correct.

Use the AI you already have

Hearth does not sell you a model. Three ways in.

Claude the Claude Code sign-in you already have

ChatGPT a sign-in, through the open-source Codex CLI

Anything else the command-line tool you already run

Your game is a normal folder. Move it, back it up, open it in any editor. Download Hearth

The engine that came before

Hearth used to be a 2D game engine, preserved on engine-v1 at v1.2.1 and no longer developed.