hatch-pet-v1

hatch-pet-v1 is a skill for Codex from legeling/awesome-codex-pet. It costs 107 tokens per session (5,316 once invoked), scanned A, a copy of hatch-pet, MIT.

A workflow for creating, repairing, checking, previewing, and packaging animated pet spritesheets for the legacy Codex v1 format. A spritesheet is one image containing many animation frames arranged in a grid.

In plain words
What is it for?
Use it to make pet artwork, create animation rows, extract frames, check the result with contact sheets or videos, and package the final spritesheet.
Why use it?
It organizes the many steps needed to turn character art or references into a correctly formatted animated pet.

Skill for Codex

Written for Codex: agents/openai.yaml present. Also seen: mentions subagents; installed under .agents/ (shared by several agents); mentions Codex.

Good fit Use it to make pet artwork, create animation rows, extract frames, check the result with contact sheets or videos, and package the final spritesheet.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/legeling/awesome-codex-pet/hatch-pet-v1
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.

Any agent
npx skills add legeling/awesome-codex-pet --skill hatch-pet-v1
Clone the repo
git clone --depth 1 https://github.com/legeling/awesome-codex-pet

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-v1

README.md
[![agentmods](https://agentmods.dev/badge/skills/legeling/awesome-codex-pet/hatch-pet-v1/github.svg)](https://agentmods.dev/skills/legeling/awesome-codex-pet/hatch-pet-v1)
Your own site
<a href="https://agentmods.dev/skills/legeling/awesome-codex-pet/hatch-pet-v1"><img src="https://agentmods.dev/badge/skills/legeling/awesome-codex-pet/hatch-pet-v1/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for hatch-pet-v1

Your own site · 80×15
<a href="https://agentmods.dev/skills/legeling/awesome-codex-pet/hatch-pet-v1"><img src="https://agentmods.dev/badge/skills/legeling/awesome-codex-pet/hatch-pet-v1.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 107 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 5,316 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin 89% 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 $0.00107 $0.05316
Opus 5 $0.00053 $0.02658
Sonnet 5 $0.00021 $0.01063
Haiku 4.5 $0.00011 $0.00532

Measured 10d ago against content hash 8d6fd6a644f2, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

hatch-pet-v1 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 10d ago.

The scan reads SKILL.md. This mod also ships 16 executable files (scripts/compose_atlas.py, scripts/derive_running_left_from_running_right.py, scripts/extract_strip_frames.py, …), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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

89% identical to hatch-pet — 58 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.

.agents/skills/hatch-pet-v1/SKILL.md · 336 lines

How it starts

The opening of the file, as written. The whole thing — 336 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Hatch Pet v1

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.

Use this skill's scripts for deterministic work only: preparing prompts and manifests, ingesting selected $imagegen outputs, extracting frames, validating rows, composing the final atlas, creating QA media, and packaging.

Hard boundary: do not create, draw, tile, warp, mirror, or synthesize pet visuals with local Python/Pillow scripts, SVG, canvas, HTML/CSS, or other code-native art as a substitute for $imagegen. For a normal pet run, expect up to 10 visual generation jobs: 1 base pet plus 9 row-strip jobs. The only exception is running-left, which may be derived by mirroring running-right only after running-right has been generated, visually inspected, and explicitly approved as safe to mirror. If mirroring is not appropriate, generate running-left as a normal grounded $imagegen row. If those calls are too expensive, blocked, or unavailable, stop and explain the blocker instead of fabricating row strips locally.

Read the full file on GitHub · 336 lines

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. 10d ago First seen · 336 lines · 107 tokens per session scan A 8d6fd6a644f2

Subscribe to this mod's changes

hatch-pet-v1 is a skill published in the GitHub repository legeling/awesome-codex-pet (888 stars, last pushed today), licensed MIT. It adds 107 tokens to every session and 5,316 once invoked, about $0.0005 per session on Opus 5. A static security scan graded it A with 0 findings. It is 89% identical to hatch-pet, differing in 58 lines, and is treated as a copy.