hatch-pet

hatch-pet is a skill for Codex from wolfenazz/YzPzCode. It costs 114 tokens per session (5,266 once invoked), scanned A, a copy of hatch-pet, Apache-2.0.

A workflow for creating and packaging animated pixel-art pet spritesheets that work with Codex's floating pet companion. It handles animation frames, atlas layout, previews, and validation.

In plain words
What is it for?
Use it to turn character art or references into importable pet animations such as idle, running, or waving.
Why use it?
Animated sprite sheets require consistent frame sizes and placement, which is easy to get wrong by hand.

Skill for Codex

Written for Codex: reads ~/.codex or $CODEX_HOME. Also seen: mentions subagents; mentions Codex.

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/wolfenazz/yzpzcode/hatch-pet
Any agent
npx skills add wolfenazz/YzPzCode --skill hatch-pet
Clone the repo
git clone --depth 1 https://github.com/wolfenazz/YzPzCode

Made for: Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for hatch-pet

README.md
[![agentmods](https://agentmods.dev/badge/skills/wolfenazz/yzpzcode/hatch-pet.svg)](https://agentmods.dev/skills/wolfenazz/yzpzcode/hatch-pet)
Your own site
<a href="https://agentmods.dev/skills/wolfenazz/yzpzcode/hatch-pet"><img src="https://agentmods.dev/badge/skills/wolfenazz/yzpzcode/hatch-pet.svg" alt="Measured on agentmods" height="20"></a>
Per session 114 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 5,266 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 100% copy Near-identical to another mod in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00114 $0.05266
Opus 5 $0.00057 $0.02633
Sonnet 5 $0.00023 $0.01053
Haiku 4.5 $0.00011 $0.00527

Measured 2d ago against content hash 8a5b7b153a7e, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-05, from the pricing page.

Security

Grade A, and why

hatch-pet scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

This is a copy

100% identical to hatch-pet — 6 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

app/desgin/plugins/_official/examples/hatch-pet/SKILL.md · 356 lines

How it starts

The opening of the file, as written. The whole thing — 356 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Hatch Pet

Open Design integration. This is the unmodified Codex hatch-pet skill, vendored under skills/hatch-pet/ so any Open Design agent can run it. After the skill finishes packaging, the resulting spritesheet.webp (under ${CODEX_HOME:-$HOME/.codex}/pets/<pet-name>/) can be imported into the floating pet companion via Settings → 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:

${CODEX_HOME:-$HOME/.codex}/skills/.system/imagegen/SKILL.md

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.

Read the full file on GitHub · 356 lines

Files

What ships with it

4 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 356 lines · 114 tokens per session scan A 8a5b7b153a7e

Subscribe to this mod's changes

hatch-pet is a skill published in the GitHub repository wolfenazz/YzPzCode (13 stars, last pushed yesterday), licensed Apache-2.0. It adds 114 tokens to every session and 5,266 once invoked, about $0.0006 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to hatch-pet, differing in 6 lines, and is treated as a copy.