Agent skill · design visual · nexu-io
hatch-pet
Create, repair, validate, preview, and package Codex-compatible animated pet spritesheets from character art, screenshots, generated images, or visual references. Use when a user wants to hatch a Codex pet, create a custom animated pet, or build a built-in pet asset with an 8x9 atlas, transparent unused cells, row-by-row animation prompts, QA contact sheets, preview videos, and pet.json packaging. This skill composes the installed $imagegen system skill for visual generation and uses bundled scripts for deterministic spritesheet assembly.
Why this skill is useful
Adds bundled scripts for deterministic spritesheet assembly and packaging that extend the AI's capabilities in creating animated pet assets.
What it needs
Requires imagegen installed locally. About 11k tokens when loaded. Last updated 2026-08-07. 84,236 stars on the source repository.
What this skill does
Hatch Pet OpenDesign integration. This is the unmodified Codex hatch-pet skill, vendored under skills/hatch-pet/ so any OpenDesign agent can run it. After the skill finishes packaging, the resulting spritesheet.webp (under ${CODEXHOME:-$HOME/.codex}/pets/<pet-name>/) can be imported into the floating pet companion via Settings → General → Pets → Import Codex sprite. The import flow auto-detects the 8×9 / 192×208 atlas and lets the user pick which animation row to play (idle, running-right, waving, …). Overview Create a Codex-compatible animated pet from a concept, one or more reference images, or both. This skill owns pet-specific prompt planning, animation rows, frame extraction, atlas geometry, QA, previews, and packaging. It delegates visual generation to $imagegen. User-facing inputs are optional. If the user omits a pet name, infer one from the concept or reference filenames; if that is not possible, choose a short appropriate name. If the user omits a description, infer one from the concept or references. If the user omits reference images, generate the base pet from text first, then use that base as the canonical reference for every animation row. Generation Delegation Use $imagegen for all normal visual generation. Before generating base art, row strips, or repair rows, load and follow the installed image generation skill: Do not call the Image API directly for the normal path. Let $imagegen choose its own built-in-first path and its own CLI fallback rules. If $imagegen says a fallback requires confirmation, ask the user before continuing. When invoking $imagegen from this skill, pass the generated pet prompt as the authoritative visual spec. Do not wrap it in the generic $imagegen shared prompt schema and do not add extra polish, hero-art, photo, product, or illustration-style augmentation. Pet prompts should stay terse, sprite-specific, and digital-pet oriented; only add role labels for input images and any essential user constraint. …
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills nexu-io/hatch-pet--6f38a6