Codex Pet

# 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 API. - You want **batch Codex Pet generation** from a folder of source images (one canonical call per pet). - You're entering the OpenAI Codex Pet contest with a different model behind the visuals. - You said "codex pet", "/hatch", "make me a codex pet", "spritesheet.webp", "desktop pet for codex" explicitly.

## Codex Pet animation rows

Codex reads one fixed atlas: 8 columns, 9 rows, 192x208 cells. Each Codex Pet row corresponds to one animation state with a specific number of leading frames.

| Row | State | Used columns | Frames | Codex Pet behavior | |---|---|---|---|---| | 0 | idle | 0-5 | 6 | calm breathing/blinking; the reduced-motion first frame for the Codex Pet | | 1 | running-right | 0-7 | 8 | Codex Pet locomotion to the right | | 2 | running-left | 0-7 | 8 | mirrored locomotion to the left | | 3 | waving | 0-3 | 4 | greeting / attention gesture | | 4 | jumping | 0-4 | 5 | anticipation, lift, peak, descent, settle | | 5 | failed | 0-7 | 8 | error / sad / deflated reaction | | 6 | waiting | 0-5 | 6 | patient idle variant | | 7 | running | 0-5 | 6 | active working / in-progress loop (NOT foot-running) | | 8 | review | 0-5 | 6 | focused / inspecting / thinking |

Trailing cells after each row's last used column must be fully transparent.

## Codex Pet style

The Codex Pet visual house style:

- **EXAGGERATED chibi proportions**: head occupies ~60 percent of total figure height; body and legs are tiny stubby and short. The whole figure should fit a near-square bounding box. - pixel-art-adjacent low-resolution mascot, chunky silhouette - thick dark 1-2 px outlines, visible stepped pixel edges - limited palette, flat cel shading, simple expressive face, tiny limbs - transparent background

Avoid: motion lines, drop shadows, glows, sparkles, floating effects, text labels, scenery, white/black backgrounds.

## Prerequisites

1. **RunComfy CLI** — `npm i -g @runcomfy/cli` 2. **RunComfy account** — `runcomfy login`. CI alternative: `RUNCOMFY_TOKEN=<token>`. 3. **ImageMagick** — `brew install imagemagick` (macOS) or `apt-get install imagemagick` (Linux). Provides the `magick` command for the deterministic atlas assembly. 4.