Pixel art skill for AI agents

pixel-art is a skill from the Summer skill library: a guide your AI agent reads when the task matches, so it builds the good version on the first try. Generate pixel-art sprites, items, tiles and portraits at a set resolution with a limited palette.


Status	Stable
Domains	2D art, Asset pipeline
Version	`1.0.4`
Engine version	`>=4.6`
Recommended set	Yes, installed by `--recommended`

When your agent uses it

Generating pixel-art assets — sprites, items, tiles, portraits — in a pixel style at a specific resolution (32x32, 64x64, 128x128)
A retro or low-resolution 2D game needs sprites, tiles, or portraits on a fixed grid with a limited palette

Install

summer setup installs every skill for your agent. To add only this one:

npx -y summer-engine@latest skills install pixel-art --agent claude-code

Swap claude-code for your agent, such as codex or cursor. See Skills for every option.

The skill

This skill generates pixel-art sprites, items, tiles, icons and portraits at a target resolution (32×32, 64×64, 128×128). Pixel art has hard constraints (grid alignment, limited palette, no anti-aliased edges) that diffusion models break by default. The prompt patterns and post-processing below make the output read as pixel art instead of a blurry small image. Backing operation: assets.generate_image with an explicit pixel-art prompt. Two things about that operation you have to know before writing a call:

There is no "pixel" style preset. style accepts exactly realistic, cartoon, anime, none; anything else is coerced to none. Only cartoon and anime do anything at all (they append a short suffix); realistic and none append nothing. So style: "pixel" is identical to style: "none" — the pixel look has to come entirely from the prompt. Use style: "none".
There is no options object and no negative prompt. Shape is aspectRatio (1:1 default, right for sprites and tiles), a minimum size is width + height, and seed repeats a look on Nano Banana models. Exclusions go in the prompt text. The model renders far above the pixel grid either way; the target resolution comes from the downscale below.

Pixel-perfect output is enforced in Summer Engine with Nearest texture filtering and by downscaling to the target resolution after generation.

When to use

“Generate a 32×32 sword icon for the inventory.”
“I need a pixel-art portrait of the merchant for the dialogue UI.”
“Make a 64×64 enemy sprite — a slime monster.”
“Generate a tileset for a grass / dirt / stone biome at 16×16 per tile.”
The game has a pixel-art aesthetic and the user wants assets in-style.

When NOT to use

The user wants a high-resolution painterly portrait → character-portrait.
The user wants animated frames (walk cycle, attack) → sprite-sheet (pixel art is harder for sprite sheets — read that skill’s caveats).
The user wants a tileable seamless texture (not pixel art) → tileable-texture.
The game is 3D / non-pixel — verify the user actually wants pixel before generating.

Steps

1. Lock the resolution and palette

Ask the user (or read .summer/GameSoul.md):

Resolution per asset: 16×16, 32×32, 64×64, 128×128 are standard. Sprites usually 32 or 64; portraits 64 or 128; icons 16 or 32.
Palette: named retro palette (NES 56-color, Game Boy 4-color green, PICO-8 16-color, Sweetie-16) OR custom hex list OR “no palette restriction.”
Outline: hard black outline, colored outline, or no outline?

Write to .summer/pixel-anchor.md so the rest of the cast/tileset stays consistent:

## Pixel anchor

base resolution: 32x32 per sprite
palette: PICO-8 16-color
outline: hard 1px dark outline (NOT pure black — use the palette's darkest color)
shading: 3-tone (light, mid, shadow), no gradients, no AA

2. Search for existing assets

assets.search({ query: "<subject> pixel", assetType: "2d_image", scope: "all" })

3. Build the prompt

Pattern:

pixel art <subject>, <resolution>, <palette>, <outline rule>, <shading rule>, no anti-aliasing, no blur, sharp pixel edges, transparent background

The model can’t actually generate at 32×32 — it generates at 1024×1024 with pixel-art style. You then downscale to the target resolution post-import for crisp pixels.

4. Generate

assets.generate_image({
  prompt: "pixel art slime monster, 32x32 sprite, PICO-8 palette, hard 1px outline in palette's darkest color, 3-tone shading, no anti-aliasing, no blur, sharp pixel edges, front-facing. Not blurry, no smooth gradients, no soft edges, not photorealistic, no 3D render.",
  model: "nano-banana-2",
  style: "none",
  removeBackground: true
})

Two deliberate choices there:

The negations live in the prompt. There is no negative_prompt argument. Diffusion models honor in-prompt negations less reliably than a real negative-prompt field, so state them as plain sentences at the end and expect to regenerate more often than you would on a provider UI that exposes the field.
removeBackground: true is its own argument. It runs a background-removal pass after generation and returns a PNG with true alpha. Prefer it over asking for “transparent background” in the prompt, which makes models paint a literal checkerboard.

5. Downscale to target resolution

The generated image is 1024×1024 pixel-style. To get true crisp pixels at 32×32:

Import to the engine, then in the import dock set Filter: Nearest (no smoothing).
For a true 32×32 atlas/icon, downscale in an external editor (Aseprite, GIMP “nearest neighbor”) to 32×32 before importing. Aseprite’s “Sprite > Sprite Size” with Nearest gives the cleanest result.
In Summer Engine, set Project Settings → Rendering → Textures → Default Texture Filter: Nearest if the entire game is pixel art. This disables bilinear smoothing project-wide.

6. Import and wire

summer_import_from_url(url="<fileUrl>", path="res://sprites/slime.png")

For a Sprite2D:

summer_set_prop(
  scenePath="res://main.tscn",
  path="./Slime/Sprite2D",
  key="texture",
  value="res://sprites/slime.png"
)

texture is a property on the node, so it is summer_set_prop. summer_set_resource_property is for reaching inside a resource the node already holds (mesh size, material albedo) and needs all five of scenePath, nodePath, resourceProperty, subProperty, value — there is no two-argument form. Confirm Filter: Nearest is set in the import dock OR project-wide.

Prompt patterns

Goal	Prompt that works	Why
Item icon (32×32)	`pixel art iron sword icon, 32x32, NES palette, hard outline, 3-tone shading, no AA, sharp edges, transparent background, three-quarter view`	Three-quarter view reads better than pure side at 32px
Character sprite (64×64)	`pixel art knight character sprite, 64x64, PICO-8 palette, hard 1px outline, 3-tone shading, front-facing idle pose, no AA, sharp edges, transparent background`	Specifying “idle pose” prevents action poses that don’t tile into a sheet
Pixel portrait (128×128)	`pixel art portrait of a young witch, 128x128, custom muted fantasy palette, hard outline, 4-tone shading, bust framing, looking forward, no AA, no blur, transparent background`	Higher resolution allows 4-tone shading; 32px is too small for that
Tileset (16×16/tile)	`pixel art top-down tileset, grass-to-dirt transition, 16x16 per tile, 3x3 grid layout, NES palette, hard outline between tiles, 3-tone shading, no AA, sharp edges`	Tilesets render best in a labeled grid layout
Background object (64×64)	`pixel art mossy boulder, 64x64, fantasy palette, hard outline, 3-tone shading, no AA, transparent background, three-quarter view`	Background props benefit from three-quarter for depth
GB-style asset (Game Boy)	`pixel art skeleton enemy, 32x32, Game Boy 4-color green palette (#0f380f, #306230, #8bac0f, #9bbc0f), hard 1px outline, 2-tone shading, no AA`	Naming the 4 hex codes locks the palette

Bad prompts (and why)

Bad	Failure mode
`8-bit sword`	”8-bit” is interpreted loosely. Returns a smooth render of a sword with vague pixel feel. Specify resolution + palette + “no AA” explicitly.
`pixel art knight, photorealistic`	Conflicting directives. Model averages and gives you neither.
`pixel art at 32x32` with no negations	Model adds soft edges and gradient shading. Always spell out “no anti-aliasing, no blur, no smooth gradients” in the prompt itself — there is no negative-prompt argument to fall back on.
`pixel sprite walk cycle`	Walk cycles need consistent frames — single-prompt sprite sheets fail. Route to `sprite-sheet`.
`cute pixel art`	”Cute” without subject is undefined. Specify what.

Anti-patterns

Skipping the downscale. The model returns a 1024×1024 pixel-style image. If you import that as a 1024 texture, the “pixels” are actually 32-pixel blocks of soft color. Downscale to true target resolution OR set Filter: Nearest so the up-rendering doesn’t smooth.
No Filter: Nearest. The default texture filtering is bilinear. Set Nearest on import or project-wide for pixel art.
Reaching for negative_prompt or image_size. Neither exists on assets.generate_image, and a field it does not list does nothing, so the call looks like it worked and the output is off-style. Negations go in the prompt text; shape is aspectRatio, a minimum size width + height.
Inconsistent palette across the cast. Pick a named palette (PICO-8, NES, custom hex list) and re-use across every asset in the project. Different palettes = the project doesn’t read as one game.
Generating walk-cycle frames as one image. Sprite sheets via single-prompt are unreliable. Route to sprite-sheet.

Edge cases

User wants animated pixel sprites. Generate base sprite here, then per-frame variants via img2img with the base as referenceImageUrl. For more than 2-3 frames, route to sprite-sheet (and read its caveats).
User wants the entire game in pixel art. Set Project Settings → Rendering → Textures → Default Texture Filter: Nearest once. Saves you from re-setting it on every import.
User wants a high-res “pixel art” portrait that’s not actually pixelated (faux-pixel-aesthetic at full resolution). That’s character-portrait with a “pixel art aesthetic” prompt — not this skill.
User specifies a palette like “Sweetie-16” or “Endesga-32” and the model ignores it. Name the hex codes explicitly. Palette names alone are unreliable below the top 5-10 famous ones.
Tilesets need to tile cleanly. Pixel-art tile-edge cleanliness from raw generation is poor. Generate the tile grid, then fix edge seams by hand in Aseprite.

Without Summer Engine

In a session without Summer Engine tools (the assets profile; the summer-assets skill has the whole loop), do steps 1-5 and skip step 6 (import and wiring). In step 5, downscale with nearest-neighbour in an image editor; the engine settings there do not apply. Pass out with the person’s folder so the PNG lands there (the summer-assets skill says how), and tell them to turn texture filtering off in their engine.

Fallback (no MCP)

Print the call:

assets.generate_image({
  prompt: "<pixel art prompt with full anchor>. Not blurry, no smooth gradients, no anti-aliasing.",
  model: "nano-banana-2",
  style: "none",
  removeBackground: true
})

The Summer dashboard also exposes a negative-prompt control — if the user is running it there, tell them to set square + a real negative prompt. Tell the user to run via the Summer dashboard, downscale in Aseprite/GIMP to true target resolution with nearest-neighbor, then summer_import_from_url (or drop into res://sprites/) and set Filter: Nearest. If MCP is offline entirely: open Aseprite or Piskel and hand-author the asset. For pixel art at small resolutions, hand-authoring is often faster than fixing a generation.

Handoff

After the asset is wired:

More assets in the same style → re-invoke this skill, re-use the pixel anchor.
Animation frames for the sprite → sprite-sheet with the base sprite as anchor.
Pixel UI → re-invoke with UI subjects (icons, button frames) at appropriate resolution.
Tilemap setup → scene-composition for TileMap / TileMapLayer wiring.

From a shell

No Summer MCP tools in this session? Run each one as a command; when summer --version is missing or below 4.0, use npx -y summer-engine@latest in place of summer. Fields are flags in kebab-case (--scene-path res://main.tscn) or one --input '<json>', and summer ops describe <op> prints the exact input. The summer-cli skill has the rest.

In this skill	Command
`assets.generate_image`, `summer_assets_generate_image`	`summer assets generate-image`
`summer_assets_search`	`summer assets search`
`summer_docs_read`	`summer docs read`
`summer_import_from_url`	`summer engine import-from-url`
`summer_set_prop`	`summer engine set-prop`
`summer_set_resource_property`	`summer engine set-resource-property`

character-portrait: Generate one polished character bust for dialogue UI, character select, lore cards or codex entries.
sprite-sheet: Generate animated 2D character sprite sheets (walk, attack, idle, death) for AnimatedSprite2D.
tileable-texture: Generate a seamless tileable texture for walls, floors or terrain, wired as a StandardMaterial3D albedo.
asset-strategy: Route any ‘I need a [thing]’ asset request to the right skill: 2D, 3D, audio, video, VFX or animation.
create-asset-sheet: Generate a pack of 2D assets from one prompt (tile sheet, UI kit, character pack, biome), sliced.

Source: library/skills/pixel-art/SKILL.md, rendered from summer-engine@4.3.0 on npm.

​When your agent uses it

​Install

​The skill

​When to use

​When NOT to use

​Steps

​1. Lock the resolution and palette

​2. Search for existing assets

​3. Build the prompt

​4. Generate

​5. Downscale to target resolution

​6. Import and wire

​Prompt patterns

​Bad prompts (and why)

​Anti-patterns

​Edge cases

​Without Summer Engine

​Fallback (no MCP)

​Handoff

​See also

​From a shell

​Related skills