0x0funky/agent-sprite-forge

Agent Sprite Forge is a set of agent skills for producing game art: from one approved master still it generates a character's action animations, and it also builds maps and tiles. It is aimed at 2D game developers who already drive Claude Code, Codex or Grok and want sprite packages rather than a single generated image.

What actually changes

The documented workflow is master → set → finish → export. You prompt the agent to create a master still; master_still.py writes the prompt, makes several takes, applies a targeted edit, and records the approved still in master.json. The agent then makes one image-to-video clip per action (idle, walk, run, attack, jump, hurt). Deterministic Python tools gate each take on area, feet, identity, zoom, edges, background, motion, end pose and timing, key it with a soft matte, register it, choose loops by measurement, retime one-shots, and package the result Agent Sprite Forge README.

Two mechanisms do the practical work. The soft-matte keyer replaces chroma-key fringing: the author reports purple fringe 0.704 → 0 and 271 s → 44 s for 145 frames. One-shot retiming cuts slow-motion generator footage to game length, reported at 4.1 s → 0.7 s for an attack. These are author-reported numbers from the 0.6 October 2026 live runs, not independent measurements validation record.

Use paths and prerequisites

Claude Code users install it as a plugin, which needs Python 3.10+ and numpy, Pillow and scipy. Codex and Grok users clone the repository and run the install script, which also writes a sha256 manifest and supports a later drift check. Video, sprite sets, packaging and scene loops need ffmpeg 5.1+ on PATH, with libvpx-vp9 and libx264. Start a fresh agent session so the skills load install and requirements.

Image and video generation needs either a configured API key for OpenAI, Gemini, xAI, BytePlus or fal.ai, or your own signed-in Codex or Grok CLI. Without either, or on explicit request, codeart2d draws code-generated art as a disclosed last resort. Providers are tried in a fixed order, and a key counts as consent to call without a per-call question. Every call, including local ones, is written to a spend ledger, and there is no budget cap unless you set one routes and providers.

Outputs and limits

Packages include animation.json 3.0 with a PNG atlas, VP9-alpha WebM, packed-alpha MP4, plus Godot SpriteFrames/Sprite3D and Aseprite JSON exports. Maps export to Tiled, Godot 4 and LDtk engine exports. The README explicitly warns that the 0.4.0 Godot, LDtk and Aseprite exports have only been proven at parse level; nobody has opened them in those editors.

The scripts are not the creative judge: numeric QA does not approve anatomy or motion, so the agent reviews contact sheets and you approve the master. Image-to-video models drift on fast limbs and jumps, so retakes on run and jump should be expected; the known-limitations document lists what is and is not proven known limitations.

The MIT license covers the repository's code and documentation only. Generated images and videos remain subject to each provider's terms, and the author advises using original characters or IP you control for commercial projects licensing.