PET HATCHERY
Build a little companion with a big personality.
A custom animated pet for Codex, Claude Code and Cursor, hatched in about two minutes.
Free. No account. Installs in Codex, OpenPets, Claude Code and Cursor.
WHAT YOU GET
A zip, not a screenshot.
Every hatch ends with a real pack. Frames cut to the exact cell size, alpha cleaned, the whole sheet checked against OpenAI's own validator before it reaches you. A pet that fails never gets downloaded.
- A 1536 x 1872 atlas, 8 by 9 grid of 192 x 208 frames
- 57 frames across 9 states: idle, running, waving, jumping, failed, waiting, working, review
- A
pet.jsonmanifest, named and pointed at the sheet - Clean alpha, so no colored halo on a dark terminal
- One zip, one folder, no build step
HOW IT WORKS
Four steps, about two minutes.
You answer four short questions in the browser. Hatchery draws the base pose, builds eight animation rows from it, then cuts every frame and assembles the atlas while you watch.
-
01
Style.
Pixel, clay, plush or sticker. Everything after follows that choice.
-
02
Character.
Say what it is. A toad, a goose, a small alien.
-
03
Details.
Name it, color it, add the detail that makes it yours.
-
04
Hatch.
Base pose, eight rows, every frame cut and checked.
THE PETS
Every coding agent should have a pet.
Every one of these came out of the same builder you are about to use. Take one as it is, or hatch something nobody has yet.
Loading the pets...
WHERE IT LIVES
One file, every harness.
Codex reads the format natively. OpenPets carries the same unchanged atlas to Claude Code, Cursor, OpenCode, Gemini CLI and Pi CLI. Unzip into your pets folder, restart the agent, and it is there.
- macOS and Linux:
~/.codex/pets/<name>/ - Windows:
%USERPROFILE%\.codex\pets\<name>\ - Everywhere else: install OpenPets once, keep the same file
- About a minute, start to finish
DAILY DROPS
A new pet every morning.
One hatches each day and gets its own page in the gallery. Send yours and it joins the queue with your name and a link back to you.
One email a day, the pet and nothing else. Leave any time.
QUESTIONS
The things people ask.
What is a Codex pet?
A small animated character that lives in your coding agent's window and changes with what the agent is doing: idle, running, waving, jumping, failed, waiting, working, review. Codex set the format and other harnesses picked it up.
Is Hatchery free?
Yes. No account, no card, nothing to install first. You answer four questions in the browser and download the pack.
Where do the files go?
On macOS and Linux, ~/.codex/pets/<name>/. On Windows, %USERPROFILE%\.codex\pets\<name>\. The folder holds pet.json and the sprite sheet. Restart your agent and the pet is there.
Does it work with Claude Code, Cursor or Gemini CLI?
Yes, through OpenPets, which bridges the Codex pet format to Claude Code, Cursor, OpenCode, Gemini CLI and Pi CLI. The same atlas installs unchanged. One pet, every harness.
What is in the download?
A zip holding a 1536 x 1872 transparent atlas, 8 columns by 9 rows of 192 x 208 frames, one row per state, plus the pet.json manifest. Drop the folder in and you are done.
Why do sprites from other tools have ugly edges?
Most of them scale after cutting frames, which leaves color on pixels that should be fully transparent. You see it as a halo on dark backgrounds. Hatchery exports at native cell size and cleans the alpha.
Is my pet checked before I get it?
Yes. Every pack runs through OpenAI's open-source pet validator before it is zipped. If a pet fails, it never reaches the download.
Can I put my own pet in the gallery?
Yes. Submitted pets get their own page with your name and a link back to you. Use the submit button on the gallery. Submissions are reviewed each morning.
There is still a space at the end of the line.
Pick a style, say what it is, name it. The rest is drawn, cut, checked and zipped for you.
MADE BY
A one-person studio in Kentucky. Hatchery is built in Elizabethtown, Kentucky by one person who wanted it to exist and got tired of waiting for somebody else to make it.