Agent skill · genmedia-labs
codex-pet
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.
What it needs
About 11k tokens when loaded.
What this skill does
Codex Pet — Pro Pack on RunComfy runcomfy.com · GPT Image 2 edit endpoint · docs Codex Pet generator on RunComfy. Turn one source image into a Codex-compatible custom Codex Pet — pet.json + spritesheet.webp — drop it into ${CODEXHOME:-$HOME/.codex}/pets/<name>/, Codex picks it up next to the 8 built-in Codex Pets. 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 ${CODEXHOME:-$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 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 RUNCOMFYTOKEN plus runcomfy and magick binaries — no Codex Pro, no $imagegen, no OPENAIAPIKEY. 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). …
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills genmedia-labs/codex-pet