Hatch Pet Agent Skill

Create, repair, validate, visually QA, and package Codex-compatible v2 animated pets from character art, generated images, company or…

Context cost
25.8k tokensestimated from the bundle, loaded when it triggers
Bundle
29 files · 298.5 kB23 scripts among them — read before you run
Licence
Apache-2.0the author’s own terms
Last change
—no release on file
Servers it uses
Noneruns standalone

What it does

Create, repair, validate, visually QA, and package Codex-compatible v2 animated pets from character art, generated images, company or prospect brand cues, or visual references. Use for any new Codex pet, custom mascot, non-pixel pet style, brand-inspired pet, existing-pet repair, or 8x11 spritesheet workflow requiring all 9 standard animation rows, 16 look directions, deterministic assembly, QA artifacts, and spriteVersionNumber 2 packaging.

What this skill changes about the agent has not been set out here as a list. Its SKILL.md, shown below, says it in the author’s own words.

gamedev

The skill itself

A skill is instructions the model reads, so you can see what you are getting: below is the start of its SKILL.md. The front matter loads with every session, the body loads when the skill triggers, and the whole file comes with the install.

SKILL.md85.5 kB · preview
--- name: hatch-pet ---
6# Hatch Pet
7
8## Overview
9
10Create a Codex-compatible v2 animated pet from a concept, brand cue, company/prospect name, one or more reference images, or any combination of those inputs. Every newly hatched pet is an 8x11 atlas with the 9 standard animation rows plus 16 clockwise look directions and is packaged with spriteVersionNumber: 2. The intermediate 8x9 atlas exists only to assemble and review rows 0-8; never package it as a new pet.
11
12User-facing inputs are optional. If the user omits a pet name, infer one from the concept, brand, company, or reference filenames; if that is not possible, choose a short friendly 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.
13
14## Existing Inputs And Upgrades
15
16Treat character art, generated images, standard or v2 atlases, contact sheets, and built-in pet art as first-class grounding inputs.
17
18- Preserve user-provided art as a generation reference; do not assume it already has final cell geometry.
19- For an existing valid 8x9 atlas, use it as the rows 0-8 intermediate after deterministic and visual validation, then generate rows 9-10 and package the result as v2.
20- For an existing 8x11 atlas, preserve approved standard rows. If a look cell fails, correct the complete containing 8-frame row before deterministic reassembly. Never package a newly generated one-off repair cell beside cells from another generation.
21- For a built-in pet, extract and use its atlas or neutral/idle cell as the canonical identity reference.
22- Include every image that defines head shape, face, palette, markings, material, flame/ears/hair, props, or look mechanics in look-direction generation.
23- When a renderer or source provides a dedicated neutral/front frame, pass it through --neutral-cell; otherwise use the approved idle/default frame. The 16 directional cells never treat 000 as neutral.
24
This is a preview of SKILL.md. Download or install the skill to get the whole thing.
In the file
SKILL.md11,570 words
Files29
LicenceApache-2.0
Why you can read it

Nothing in a skill executes. The client loads the text and the model follows it, so a skill can be audited the way a runbook is — by reading it.

What it costs in context

Skills are not billed by the call. They are paid for in context: every token the instructions occupy is a token your code, your diff and your conversation cannot use. Here is what this one takes and when it takes it.

≈120
always loaded
The name and description, so the model knows the skill exists and when to reach for it.
25,630
on trigger
The instruction body and 28 supporting files, read only when the skill fires.
12.9%
of a 200k window
Ten skills this size would not fit in the window together.
050k100k150k200k context window

25.8k tokens, estimated from the bundle at four bytes to the token, held for the rest of the session once it triggers. Heavy. Teams tend to install this one per project rather than globally, and load it only when the job comes up.

Servers bill, skills cost

A server charges by the month. A skill charges once per session, in context, and then keeps charging it for as long as the session lives.

Before and after

The same question, put to the same model twice: once as it comes, and once with these instructions loaded.

No worked example has been published for this skill yet.

The procedure it runs

The procedure has not been set out here step by step. It is in the body of its SKILL.md: the start of it is shown above, and the whole file comes with the install.

Prose, not code

These steps are written for a model to follow, not executed by a runtime. It can still be told to skip one, and it will say so when it does.

Servers it uses

None. This skill calls no MCP servers at all.

Everything it needs is in the instructions, so it works in a project with nothing connected — the model reads the file and changes how it works with what it can already reach.

Its SKILL.md does not declare which tools it asks the agent for, so what it touches is whatever the instructions themselves ask for — read them before you install it.

What it asks for
Writes filesnot declared
Network accessnot declared

This SKILL.md carries no allowed-tools line, so neither is declared. A skill grants no permissions of its own — it can only ask for tools your client already has.

What it will not do

Every skill is narrow, and the useful ones say where they stop. These are the jobs this one is the wrong tool for.

What this skill is not for has not been published here. Nothing is implied by that: it is a section the author has not filled in.

What is in the bundle

29 files, 298.5 kB on disk. Mostly text — the instructions the model reads — with 23 scripts in it that your client would run only if the instructions tell it to.

  • SKILL.md85.5 kB
  • LICENSE.txt10.8 kB
  • agents/openai.yaml0.2 kB
  • references/animation-rows.md2.6 kB
  • references/codex-pet-contract.md1.3 kB
  • references/qa-rubric.md2.6 kB
  • scripts/assemble_extended_atlas.py21.9 kB
  • scripts/combine_direction_blind_verdicts.py2.0 kB
  • scripts/compose_atlas.py5.8 kB
  • scripts/compose_cardinal_anchor_strip.py1.4 kB
  • scripts/derive_running_left_from_running_right.py5.2 kB
  • scripts/despill_chroma_edges.py10.8 kB
  • scripts/extract_cardinal_anchors.py5.0 kB
  • scripts/extract_strip_frames.py13.9 kB
  • scripts/inspect_frames.py9.5 kB
  • scripts/make_contact_sheet.py3.7 kB
  • scripts/make_direction_blind_qa_sheet.py5.4 kB
  • scripts/make_direction_qa_sheet.py4.9 kB
  • scripts/measure_direction_continuity.py6.7 kB
  • scripts/prepare_pet_run.py51.3 kB
  • scripts/render_animation_previews.py2.5 kB
  • scripts/validate_atlas.py10.7 kB
  • scripts/validate_direction_blind_verdicts.py3.8 kB
  • tests/test_assemble_extended_atlas.py9.6 kB
  • tests/test_chroma_matte_decontamination.py7.2 kB
  • tests/test_direction_acceptance_policy.py7.8 kB
  • tests/test_direction_blind_consensus.py1.5 kB
  • tests/test_look_row_safe_box_prompt.py4.3 kB
  • tests/test_single_final_chroma_pass.py0.6 kB
What is not in it

A skill installs nothing and depends on nothing: it is a folder your client reads. This one carries 23 scripts beside the text, so the bundle is 29 files you can review in full before installing. The Apache-2.0 licence covers the templates and examples as well as the instructions.

Install

Installing copies the bundle into your project. Nothing runs at install time — the files sit on disk until the model reads them.

# Hatch Pet · 25.8k tokens when loaded · macOS, Linux mkdir -p .claude/skills && t=$(mktemp -d) && curl -fsSL -o "$t/bundle.tar.gz" https://mcprush.com/api/skills/karanmrn-hatch-pet/bundle.tar.gz && tar -xzf "$t/bundle.tar.gz" -C "$t" && [ -d "$t/hatch-pet" ] && { [ ! -e .claude/skills/hatch-pet ] || { mv .claude/skills/hatch-pet "$t/.previous" && echo "Previous copy moved to $t/.previous"; }; } && mv "$t/hatch-pet" .claude/skills/ && echo "Installed .claude/skills/hatch-pet"
On Windows, or any OS with Node 20+
npx mcprush@latest skill add karanmrn/hatch-pet

Windows PowerShell says 'running scripts is disabled on this system'? Run Set-ExecutionPolicy -Scope CurrentUser RemoteSigned once, or type npx.cmd instead of npx (codex.cmd, gemini.cmd, grok.cmd likewise). PowerShell 7 needs neither. Writes to .claude/skills/hatch-pet/ in the current project. For every project instead, run mkdir -p ~/.claude/skills && t=$(mktemp -d) && curl -fsSL -o "$t/bundle.tar.gz" https://mcprush.com/api/skills/karanmrn-hatch-pet/bundle.tar.gz && tar -xzf "$t/bundle.tar.gz" -C "$t" && [ -d "$t/hatch-pet" ] && { [ ! -e ~/.claude/skills/hatch-pet ] || { mv ~/.claude/skills/hatch-pet "$t/.previous" && echo "Previous copy moved to $t/.previous"; }; } && mv "$t/hatch-pet" ~/.claude/skills/ && echo "Installed ~/.claude/skills/hatch-pet" (macOS, Linux) — or add --global to the npx line. The curl line replaces .claude/skills/hatch-pet/ only after the download succeeds, so files left there by another skill of the same name, or by an older release, do not mix in. A copy already there is moved aside, not deleted, and the line prints where.

Which clients pick it up on their own

A skill is a folder of text. Most of these read a skills folder and pick it up without being told; the rest take the same folder another way — an upload in the app, a parameter on an API call — and then choose it by its description just the same.

Claude Code.claude/skills/
Claude DesktopCustomize › Skills
ChatGPTSkills › Create › Upload
Cursor.cursor/skills/
VS Code.github/skills/
Codex CLI.agents/skills/
Gemini CLI.gemini/skills/
Grok Build.grok/skills/
Microsoft CopilotSkills › Upload a skill
PerplexityComputer › Skills › Upload a skill
DeepSeek Harness.dsh/skills/
Zed.agents/skills/
Devin Desktop.devin/skills/
Windsurf (legacy).windsurf/skills/
OpenAI Agents SDKInstructions or sandbox Skills
HTTP / APIa request parameter
This release
Versionnot versioned
Publishedno release date on file
PriceFree
Referencekaranmrn/hatch-pet

Versions

Its author publishes no version number, so there is nothing here to pin to: what you install is the folder as it stands today. Instructions change more often than APIs do — a skill can be rewritten entirely without anything it depends on moving.

Pinning

Nothing to pin to: this skill carries no version number of its own. What you install is what the folder holds on the day you install it.

Reviews

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