codex-pet

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---
name: codex-pet
displayName: "Codex Pet — Pro Pack on RunComfy"
description: >
  Codex Pet generator on RunComfy. Build a Codex-compatible Codex Pet
  spritesheet.webp + pet.json from a single reference image, drop it
  into `${CODEX_HOME:-$HOME/.codex}/pets/<name>/` and Codex picks it up
  as a custom Codex Pet next to the 8 built-ins. This skill produces
  the exact Codex Pet atlas Codex expects (1536x1872 PNG/WebP, 8 cols x
  9 rows, 192x208 cells, 9 animation states — idle, running-right,
  running-left, waving, jumping, failed, waiting, running, review).
  Calls OpenAI GPT Image 2 edit ONCE via the local RunComfy CLI as
  `runcomfy run openai/gpt-image-2/edit` to produce a canonical Codex
  Pet pose, then assembles all 9 animation rows programmatically with
  ImageMagick micro-transforms — no Codex Pro, no `$imagegen`, no
  OPENAI_API_KEY required, only RUNCOMFY_TOKEN. Triggers on "codex pet",
  "create codex pet", "make codex pet", "hatch codex pet", "/hatch
  image", "desktop pet codex", "codex pets", "spritesheet.webp", or any
  explicit ask to build a custom pet for OpenAI Codex.
homepage: https://www.runcomfy.com
license: MIT
---

# Codex Pet — Pro Pack on RunComfy

[runcomfy.com](https://www.runcomfy.com/?utm_source=skills.sh&utm_medium=skill&utm_campaign=codex-pet) · [GPT Image 2 edit endpoint](https://www.runcomfy.com/models/openai/gpt-image-2/edit?utm_source=skills.sh&utm_medium=skill&utm_campaign=codex-pet) · [docs](https://docs.runcomfy.com/cli/introduction?utm_source=skills.sh&utm_medium=skill&utm_campaign=codex-pet)

**Codex Pet generator on RunComfy.** Turn one source image into a Codex-compatible custom Codex Pet — `pet.json` + `spritesheet.webp` — drop it into `${CODEX_HOME:-$HOME/.codex}/pets/<name>/`, Codex picks it up next to the 8 built-in Codex Pets.

```bash
npx skills add agentspace-so/runcomfy-agent-skills --skill codex-pet -g
```

## What a Codex Pet is

OpenAI Codex Pets (released May 2026) are pixel-art animated companions that float over your desktop while Codex codes — they react to mouse interaction and Codex status (scratching head when thinking, popping a speech bubble when a task completes). Codex ships with 8 built-in Codex Pets and supports custom Codex Pets installed locally as a folder under `${CODEX_HOME:-$HOME/.codex}/pets/`.

Each custom Codex Pet folder contains exactly two files:

- `pet.json` — manifest with `id`, `displayName`, `description`, `spritesheetPath`.
- `spritesheet.webp` — Codex Pet sprite atlas, **1536x1872** PNG or WebP, 8 columns x 9 rows of 192x208 cells, transparent background.

The 9 rows correspond to 9 animation states Codex plays. Each row uses a fixed number of leading frames; trailing cells stay fully transparent.

## Why this Codex Pet skill (vs OpenAI's official `hatch-pet`)

OpenAI ships an official [`hatch-pet`](https://github.com/openai/skills/blob/main/skills/.curated/hatch-pet/SKILL.md) skill that produces the same Codex Pet artifact via the Codex-internal `$imagegen` system skill (requires Codex Pro + `$imagegen` configured).

**This Codex Pet skill is a drop-in alternative that runs via the RunComfy CLI**: a single `RUNCOMFY_TOKEN` plus `runcomfy` and `magick` binaries — no Codex Pro, no `$imagegen`, no OPENAI_API_KEY. The output Codex Pet artifact is identical — same `pet.json` shape, same `spritesheet.webp` 1536x1872 atlas, same 9 animation rows — so Codex treats this Codex Pet exactly like one made by `hatch-pet`.

This skill follows the same pattern Codex's built-in Codex Pets use: **one canonical pose, replicated across cells with ImageMagick micro-transforms** for subtle animation (1-2 px shifts, blink frames, tilt frames). That matches what the official `hatch-pet` output actually looks like cell-by-cell — the Codex Pet animation visible in the Codex desktop app is intentionally subtle.

Pick this skill when:

- You want a custom Codex Pet but don't have Codex Pro / `$imagegen`.
- You want a custom Codex Pet built via the RunComfy Model