From aradotso-trending-skills-37
Generates game-ready 2D pixel-art sprite sheets, transparent PNG frames, and animated GIFs from natural-language prompts using Codex agent planning, image generation, and local Python post-processing for background removal, frame splitting, and export.
npx claudepluginhub joshuarweaver/cascade-ai-ml-agents-misc-1 --plugin aradotso-trending-skills-37This skill uses the workspace's default tool permissions.
```markdown
Guides Next.js Cache Components and Partial Prerendering (PPR) with cacheComponents enabled. Implements 'use cache', cacheLife(), cacheTag(), revalidateTag(), static/dynamic optimization, and cache debugging.
Guides building MCP servers enabling LLMs to interact with external services via tools. Covers best practices, TypeScript/Node (MCP SDK), Python (FastMCP).
Generates original PNG/PDF visual art via design philosophy manifestos for posters, graphics, and static designs on user request.
---
name: agent-sprite-forge
description: Generate game-ready 2D sprite sheets, transparent PNG frames, and animated GIFs from natural-language prompts using the Codex agent skill $generate2dsprite.
triggers:
- generate a 2D sprite
- create a sprite sheet
- make a pixel art animation
- use generate2dsprite to create
- create an animated GIF from a prompt
- generate a sprite bundle with cast projectile impact
- make a four-direction walk sprite sheet
- create game assets from a text prompt
---
# Agent Sprite Forge
> Skill by [ara.so](https://ara.so) — Daily 2026 Skills collection.
Agent Sprite Forge is a Codex agent skill (`$generate2dsprite`) that turns natural-language prompts into game-ready 2D pixel-art assets. The agent plans the asset, calls Codex's built-in image generation, then runs a deterministic local Python post-processor to clean up backgrounds, split frames, align cells, and export transparent PNGs and animated GIFs.
---
## How It Works
1. **Agent plans** the sheet layout, frame count, view angle, and action type.
2. **Codex generates** the raw sprite sheet image (built-in image generation — no external API needed).
3. **Local post-processor** (`generate2dsprite.py`) performs:
- Magenta (`#FF00FF`) chroma-key background removal
- Frame splitting based on grid layout
- Bounding-box extraction and alignment
- Rescaling
- Transparent PNG and animated GIF export
---
## Installation
### macOS / Linux
```bash
git clone https://github.com/0x0funky/agent-sprite-forge.git
cd ./agent-sprite-forge
python3 -m pip install -r ./requirements.txt
mkdir -p ~/.codex/skills
cp -R ./skills/generate2dsprite ~/.codex/skills/generate2dsprite
git clone https://github.com/0x0funky/agent-sprite-forge.git
cd .\agent-sprite-forge
python -m pip install -r .\requirements.txt
New-Item -ItemType Directory -Force -Path "$env:USERPROFILE\.codex\skills" | Out-Null
Copy-Item -Recurse -Force `
".\skills\generate2dsprite" `
"$env:USERPROFILE\.codex\skills\generate2dsprite"
Start a new Codex session after installation so the skill is loaded cleanly.
Pillow
numpy
Install manually if needed:
pip install Pillow numpy
agent-sprite-forge/
requirements.txt
skills/
generate2dsprite/
SKILL.md
agents/
openai.yaml # Codex agent config
references/
modes.md # Asset type / mode reference
prompt-rules.md # Prompt authoring rules
scripts/
generate2dsprite.py # Local post-processor
In a Codex session, use $generate2dsprite in your prompt. The agent reads SKILL.md, plans the asset, generates the sheet, then calls the local script.
Use $generate2dsprite to create <description>.
Use $generate2dsprite to create a 3x3 idle for an ultimate earth titan.
Use $generate2dsprite to create a golden divine boar 2x2 idle animation.
Use $generate2dsprite to create a side-view lightning knight attack animation.
Use $generate2dsprite to create Omegamon attack and right-move animation assets.
Use $generate2dsprite to create a fire mage cast animation with projectile and impact.
Use $generate2dsprite to create a wizard spell bundle with cast, projectile, and impact sprites.
Use $generate2dsprite to create a fireball projectile loop and a matching explosion impact.
Use $generate2dsprite to create a top-down 4x4 player_sheet for a wandering young samurai
with a red scarf and short katana. Make a four-direction walk sprite sheet with 4 frames
per direction. Row order: down, left, right, up. Same character, same outfit, same
proportions, same pixel scale in every frame. Solid #FF00FF background. Each frame must
fit fully inside its cell, with clear margin on all sides. Retro JRPG pixel-art style.
Use $generate2dsprite to create a side-view summon entrance effect for a thunder wolf spirit.
Attach or reference an image in your Codex session:
Use $generate2dsprite to create this male character teaching animation.
Use $generate2dsprite — make an animation of this crocodile playing with the stone in its hand.
Use $generate2dsprite to create a 2D side-scrolling game similar to Mega Man. It should
include attack mechanics, map elements, and all essential features. Design everything and
create all assets using this skill. It must be an actually playable game with a cyberpunk
story setting.
For a typical sprite sheet, the output directory contains:
| File | Description |
|---|---|
raw-sheet.png | Original image from Codex generation |
raw-sheet-clean.png | After chroma-key removal |
sheet-transparent.png | Full sheet with transparency |
frame-00.png, frame-01.png, … | Individual extracted frames |
animation.gif | Assembled animated GIF |
prompt-used.txt | The exact prompt sent to generation |
pipeline-meta.json | Grid layout, frame count, frame size metadata |
For player walk sheets, additional per-direction outputs are generated:
| File | Description |
|---|---|
strip-down.png | Horizontal strip for down direction |
strip-left.png | Horizontal strip for left direction |
strip-right.png | Horizontal strip for right direction |
strip-up.png | Horizontal strip for up direction |
down.gif | Animated GIF for down walk |
left.gif | Animated GIF for left walk |
right.gif | Animated GIF for right walk |
up.gif | Animated GIF for up walk |
If you have a raw sheet image and want to run post-processing manually:
# Example: split a 3x3 sheet and export transparent frames + GIF
from PIL import Image
import numpy as np
def remove_magenta(img: Image.Image, tolerance: int = 30) -> Image.Image:
"""Replace #FF00FF background with transparency."""
rgba = img.convert("RGBA")
data = np.array(rgba, dtype=np.int32)
r, g, b, a = data[..., 0], data[..., 1], data[..., 2], data[..., 3]
mask = (
(r > 255 - tolerance) &
(g < tolerance) &
(b > 255 - tolerance)
)
data[..., 3] = np.where(mask, 0, a)
return Image.fromarray(data.astype(np.uint8), "RGBA")
def split_sheet(sheet_path: str, cols: int, rows: int, output_dir: str):
"""Split a sprite sheet into individual transparent frame PNGs and a GIF."""
import os
os.makedirs(output_dir, exist_ok=True)
sheet = Image.open(sheet_path).convert("RGBA")
total_w, total_h = sheet.size
frame_w = total_w // cols
frame_h = total_h // rows
frames = []
for row in range(rows):
for col in range(cols):
left = col * frame_w
top = row * frame_h
cell = sheet.crop((left, top, left + frame_w, top + frame_h))
clean = remove_magenta(cell)
idx = row * cols + col
out_path = os.path.join(output_dir, f"frame-{idx:02d}.png")
clean.save(out_path)
frames.append(clean)
print(f"Saved {out_path}")
# Export animated GIF
gif_path = os.path.join(output_dir, "animation.gif")
if frames:
frames[0].save(
gif_path,
save_all=True,
append_images=frames[1:],
loop=0,
duration=100, # ms per frame
disposal=2,
)
print(f"Saved {gif_path}")
# Usage
split_sheet("raw-sheet.png", cols=3, rows=3, output_dir="./output")
Reference skills/generate2dsprite/references/modes.md for the full list. Common modes:
| Mode | Description |
|---|---|
idle | Looping idle animation (e.g., 3x3 idle) |
attack | Attack action frames |
walk / player_sheet | Four-direction walk sheet (top-down RPG) |
spell_bundle | Cast + projectile + impact as separate sheets |
unit_bundle | Character unit with multiple action strips |
combat_bundle | Full combat set: idle, attack, hit, death |
projectile | Single-action projectile loop |
impact / explosion | Impact / explosion FX sheet |
fx_sheet | General visual effects sheet |
From skills/generate2dsprite/references/prompt-rules.md:
side-view, top-down, isometric, front-facing3x3, 2x4, 1x6 (columns × rows)idle, attack, walk, cast, deathsolid #FF00FF background for clean chroma-key removalretro JRPG pixel-art, 16-bit, 32x32, 64x64Same character, same outfit, same proportions, same pixel scale in every frameEach frame must fit fully inside its cell, with clear margin on all sidesUse $generate2dsprite to create a [view] [grid] [action] for [character description].
[Style notes.] [Consistency notes.] Solid #FF00FF background.
Each frame must fit fully inside its cell, with clear margin on all sides.
| Situation | Recommendation |
|---|---|
| Large creature / boss | Use 3x3 idle or 3x3 attack |
| Small spell or projectile | Use 1x4, 2x2, or 2x3 |
| Top-down RPG player | Use player_sheet mode, specify row order explicitly |
| Spell with phases | Use spell_bundle — agent generates cast, projectile, impact as separate assets |
| Reference image → sprite | Attach the image in Codex, describe the desired action |
| Inconsistent frames | Add "Same character, same outfit, same proportions, same pixel scale in every frame" to prompt |
| Clipped sprites | Add "Each frame must fit fully inside its cell, with clear margin on all sides" |
| Commercial use | Use original characters or IP you control |
Restart the Codex session. The skill directory must exist at ~/.codex/skills/generate2dsprite/ before the session starts.
ModuleNotFoundError: No module named 'PIL'pip install Pillow
The default tolerance is 30. If pink fringing remains around edges, increase it in the post-processor call, or add anti-aliasing: none, hard pixel edges to your generation prompt.
Explicitly state the grid in the prompt (e.g., 3x4 sheet, 3 columns, 4 rows). Ambiguous layouts cause the agent to guess.
Ensure the chroma-key step runs before GIF assembly. The transparent frames must be RGBA mode. If using disposal=2, confirm Pillow version ≥ 9.0.
Add explicit pixel dimensions to the prompt: each frame 64x64 pixels, total sheet 192x192.
MIT — see LICENSE.