anim8gen

Generate short game sprite animations with an agent skill.

anim8gen turns prompts like “a cat pounces,” “a knight swings a sword,” or “a pirate ship fights a kraken” into reviewable animation packages: generated frames, aligned sprites or scenes, contact sheets, and an interactive HTML preview.

The intended output is individual animation frames, including transparent-background sprites and full-frame scenes, plus an animated GIF.

It is designed for compact game loops and actions, not long-form video.

See It

Click a preview to open the interactive playback page.

anim8gen can produce tiny transparent sprites, character actions, and wider scene loops:

• Scene animation: Pirate Ship Kraken, Space Station Explosion
• Character action: Knight Sword Spark, Cat Pounce
• Small loops: Cat Tail Swish, Dragon Tail Flick

Full gallery: https://zeveck.github.io/anim8gen/

Install

Ask your agent to install both skills:

Install the anim8gen skill from github.com/zeveck/anim8gen.
anim8gen requires imagegen2, so also install the imagegen2 skill from
github.com/zeveck/imagegen2. After installing both, reload or restart the
agent so the skills are available.

anim8gen requires imagegen2 for image generation. A normal install should add the two skill directories only; it should not copy this repository's root anim8gen/ development workbench into your project.

Configure

Configure imagegen2 with an OpenAI API key. A typical setup is a project .env file:

OPENAI_API_KEY=sk-proj-your-key-here

imagegen2 loads .env itself and reports missing or invalid credentials. OpenAI may require API Organization Verification before GPT Image models are available to your API organization; if generation is denied even with a valid key, check the verification status in the OpenAI developer console.

Use

Ask your agent for a compact sprite animation. In Claude Code and similar agents, you can ask in natural language with Use anim8gen ... or invoke the skill directly with /anim8gen ....

These are user-level briefs. anim8gen expands them into stricter per-frame imagegen2 prompts with reference frames, transparent or scene background handling, alignment, and review.

Pirate Ship Kraken

Use anim8gen to make a wide 10-frame 16-bit RPG pixel art scene of a pirate
ship attacked by a kraken at sea, with the ship firing a cannon and the kraken
retreating.

Equivalent direct invocation:

/anim8gen make a wide 10-frame 16-bit RPG pixel art scene of a pirate ship
attacked by a kraken at sea, with the ship firing a cannon and the kraken
retreating.

Space Station Explosion

Use anim8gen to make a 4-frame 16-bit RPG pixel art scene of a large sci-fi
space station in deep space: intact station, flash, explosion, and debris.

Follow up with tweaks:

It should have one more frame of the pieces just floating in space.

have the debris frame twice

Knight Sword Spark

Use anim8gen to make a 3-frame transparent-background 16-bit RPG pixel art sprite
of a small brown-haired, blue-caped knight with a short sword, side view facing
right: ready, sword slash, then a small yellow spark at the sword tip.

Cat Tail Swish

Use anim8gen to make a 3-frame transparent-background 16-bit RPG pixel art
sprite of a cute orange tabby cat facing the viewer, sitting upright while its
tail swishes left and right.

Cat Pounce

Use anim8gen to make a 4-frame transparent-background 16-bit RPG pixel art
sprite of a cute orange tabby cat adventurer facing the viewer: crouch, pounce,
soft landing, then return to crouch.

Dragon Tail Flick

Use anim8gen to make a 3-frame transparent-background 16-bit RPG pixel art
sprite of a small cute green baby dragon, side view facing left, sitting with
its tail flicking upward and then curling back down.

Details that help:

• subject and action
• style, such as 16-bit RPG pixel art
• camera view, such as front, side, or isometric
• frame count, if important
• any reference image or sprite sheet to preserve identity

When references include PNG transparency, anim8gen cleans the internal copy before using it for generation. This removes visible chroma-key pixels, alpha-bleeds hidden RGB in fully transparent pixels, and reports hard binary alpha edges that can otherwise cause magenta or black artifacts. The original reference is always preserved. If exact source pixels are required, say to use the reference exactly as provided.

Preview Page

Each run creates an HTML preview page with playback controls, frame stepping, FPS control, and a checkerboard toggle for transparent sprites. The exported preview is written to assets/anim8gen/<id>/preview.html so it can be opened as a static artifact. The preview links the high-fidelity animated WebP when available and keeps GIF as a compatibility fallback. After a run, anim8gen serves this page locally by default so you can review the animation in motion.

Use the optional request word below when you want to suppress the default local preview server.

Optional Request Word

• noshow skips the preview server and does not start one.
• without noshow, anim8gen starts a local preview server and reports the preview link.

For example, this skips starting the preview server:

Use anim8gen noshow to make a 3-frame transparent-background 16-bit RPG pixel
art sprite of a cute orange tabby cat facing the viewer while its tail swishes
left and right.

Good Fits

• idle loops
• blinks, hops, pounces, emotes
• small object animations
• quick attacks and casts
• quick game asset exploration

Not a good fit for long cinematic animation, full directional sprite packs, complex multi-character scenes, or production animation authoring.

What Gets Produced

Each run keeps process state and provenance under .anim8gen/runs/<id>/. That hidden workspace contains the generated spec, raw candidates, accepted aligned frames, manifests, validation output, contact sheets, review notes, hidden preview HTML, and package reports.

The visible deliverable bundle is exported to assets/anim8gen/<id>/ by default. It contains:

• frames/ with the finished sprite or scene frames
• preview.html
• <id>.webp when animated WebP export is available
• <id>.gif
• raw/ only when the raw candidates materially differ from the final frames

The default visible output does not include tools, schemas, manifests, retry ledgers, package reports, or this repository's demo specs.

On the first package init, anim8gen adds a root .gitignore entry for .anim8gen/ so run provenance does not appear as untracked source files. The exported assets/anim8gen/<id>/ bundle is left visible so each project can decide whether to commit, move, or ignore final animation assets.

License

MIT. See LICENSE.